Clots, Strokes -- but not for bleeding strokes] Dr. You'll do very well to include such produce in your daily diet! Nowhere has this been true than with Alzheimer's. In , the FDA concluded that the use of Triclosan containing products did not pose a human health hazard. At night however, the mechanism is opposite:
Cold Thermogenesis 6: The Ancient Pathway
Deja Vecu A variant of déjà vu has given researchers a more complex understanding of the memory mechanism.
Canadian psychologist Endel Tulving had previously broken memories into two categories—episodic and semantic. Semantic broadly relates to the idea of recalling a piece of data we have committed to memory. Episodic memories are more complex, using different parts of the brain, to conjure up memory but also to interpret it as something we have experienced.
Chris Moulin at Leeds University and, earlier, David Schacter of Harvard both had reported on individuals who felt strongly familiar with people, newspaper accounts, and other subject matter with which they had no possible connection. Moulin and Conway concluded that … the deja vecu of their patients was similarly located in the temporal lobes….
Presented with a visual illusion, chronic schizophrenics could see much more clearly than a control group of normally functioning people. Yet despite this miniscule number, the auditory system is the fastest of the five senses. Researchers credit this discrepancy to a series of lightning-fast calculations in the brain that translate minimal input into maximal understanding.
The condition is linked to the same factors—high cholesterol, high blood pressure, smoking, obesity, diabetes—that play a role in many heart attacks. Just like in the heart, the condition causes narrowing or blockage in brain blood vessels. The review of the book by William Grimes in the Times is not terribly profound, and it more or less suggests that brain surgery is no less, no more complicated than other forms of surgical endeavor.
It does make clear that Firlik is a fairly vivid writer who can communicate about her world in terms the layperson can surely understand. Molecular layer of the cerebellar cortex in a case of dementia praecox S. Central nervous system of the Hirudo medicinalis G. One hundred years ago Santiago Ramón y Cajal and Camillo Golgi were jointly awarded the Nobel Prize for Physiology or Medicine for their work on revealing the structure of the brain.
This will be a permanent exhibition, but it will also tour other cities in Spain and around the world. The early period, commencing with a detailed study of the nervous system, and containing contain drawings of some of the most important pioneers in neuroscience, including Cajal, Golgi, Retzius, Nissl, Dogiel and Alzheimer.
Hippocampus of a Brainbow mouse J. Adult stem cells from human brain N. Mapping the Mind—in Detail Julie H. See Forbes , November 14, , pp. There are a dozen or so labs looking at neural circuitry of fruit flies, but Simpson is working a wider canvas than most. Most are looking at a narrow brain function: Researchers at MIT, the University of Hong Kong, and others cut a channel in the optic nerve of 53 newly born hamsters.
These short amino acids are capable of creating a molecular scaffold that can bridge such gaps. This was again tried with adult hamsters, and significant vision returned to them. Also see the Proceedings of the National Academy of Sciences. T eacher Education in Finland The Finnish education system, whatever its dilemmas, gets the very highest marks when compared with the offerings of other nations in Europe and around the world.
For this reason it is stimulating to see what has been going on there in teacher education. Current Trends and Future Scenarios. The author notes that even insular Finland must, like every other country, take account of a rapid changing society which means adding strategic and tactical flexibility to its processes in order for the nation to keep up with the times.
This contrasts, for instance, with the practices of several U. It is noted that the Finnish teacher understands that he or she must be committed to a life-long pattern of re-education. Apparently, as in the U. There still is stability in teacher employment in the primary grades. The history of education in almost every country, however, is littered with tales of intractable systems that fail to change at a rate that will keep up with the transformation society is undergoing: Finland, today, has the same complaint.
This is reinforced by the fact that central government controls so much of what is going on: Disappointingly, the article does not come to terms with the high stress atmosphere that characterizes schools every where today. That has led to a rash of student depression and even sporadic outbreaks of suicide. In the most recent test, which focused on science, Finland's students placed first in science and near the top in math and reading, according to results released late last year.
Parents of newborns receive a government-paid gift pack that includes a picture book. Some libraries are attached to shopping malls, and a book bus travels to more remote neighborhoods like a Good Humor truck. There are fewer disparities in education and income levels among Finns. All year-old students took the PISA test. Even with the potential risks that inhibitors may pose, researchers are moving forward a host of drugs that may slow and stop amyloid development: High doses of gamma-secretase inhibitors cause severe toxic effects in mice as a consequence of disrupting the Notch signal, raising serious concerns about this potential therapy.
Nevertheless, a drug candidate developed by pharmaceutical maker Eli Lilly has passed safety tests in volunteers. This kind of test is called a phase I clinical trial.
Moreover, researchers have identified molecules that modulate gamma-secretase so that A-beta production is blocked without affecting the cleavage of Notch. In Dale B. Schenk and his colleagues at Elan Corporation in South San Francisco made a groundbreaking discovery: Other researchers are pursuing nonimmunological strategies to stop the aggregation of A-beta.
Several companies have identified compounds that interact directly with A-beta to keep the peptide dissolved in the fluid outside brain neurons, preventing the formation of harmful clumps. Neurochem in Quebec is developing Alzhemed, a small molecule that apparently mimics heparin, the natural anticoagulant. In blood, heparin prevents platelets from gathering into clots, but when this polysaccharide binds to A-beta, it makes the peptide more likely to form deposits.
Of course, less physical and social activity on the part of the aged, and the less challenging environments oldsters live in, impair production of neurons and maintenance of neural circuitry. The evidence seems to point to the fact that older brains can be retrained through pertinent exercises to retain their functionality. When the ear is attentive and working hard, it funnels clearer information to brain centers that handle memory and perception.
Merzenich claims his software enables the brain, according to cognitive testing, to perform as if it were ten years younger. There is a host of research on plasticity, but this whole area of exploration is still quite controversial, and investigators still do not know how long the effects of brain training, even when effective, endure.
Also, she notes that challenged people tend to have better sustained brain function than people who have cashed in their chips and become too laid back. We remember well a chap we knew in the early 80s who, nearing retirement, got a grant from the Ford Foundation and became the oldest freshman at Harvard.
He thought, wrongly we think, that you cannot do much about the body, but that you can recharge the brain. He, incidentally, had never gotten a college education, but had paid for his kids to go to the best universities in the land, so he thought he deserved his chance at bat. It was a bizarre experience, since the grad students and teachers were fixated on getting ahead, and his fellow students were fastened on getting grades. Only he had the luxury of trying to get an education.
For the Ford Foundation, he only had to write a paper about the experience. In the early stages the honorees were involved with basic research that tried to describe the disease mechanism. With the turn of the century, researchers are looking more closely at treatments, trying to do something to at least stall the dementia progress. We have been impressed at the wide swathe of institutions represented by the winners: Flexing Your Brain The literature is now littered with hypotheses that say the brain can be stretched and be rewired, overcoming the deterioration of age and other mental defects, even surging beyond the capabilities that were apparent there at birth.
But we think the Japanese are really onto something. Train Your Brain in Minutes a Day. Having studied test subjects in his lab, Nintendo programmers have devised a hand-held game that includes drills that stimulate the brain most.
Nintendo has definitely penetrated older segments of its home market, well beyond teen age enthusiasts. The revive-your-brain market is open for the taking. But the company has turned things on end. People are clamoring for it not just for games, but also to keep a household budget, play the guitar, and study the Buddhist scripture Heart Sutra.
Since its introduction in , the DS, which responds in writing and speech, has spurred software makers to fill the Japanese market with an eclectic array of reference guides, digital books and study tools. See The Boston Globe , March 10, No less than students are enrolled. But with such an enormous course enrollment, Tal D. Their studies show that rewiring of the brain involves the formation and elimination of synapses, the connections between neurons. The technique offers a new way to examine how learning can spur changes in the organization of neuronal connections in the brain.
To study those kinds of changes in a living animal, Svoboda and his colleagues started with transgenic mice that were engineered to produce green fluorescent protein within neurons in a portion of the brain that processes tactile sensory inputs from the whiskers.
To observe changes in these neurons at high resolution, the scientists constructed a 2-photon laser scanning microscope. Importantly, it helps us understand that the brain is constantly remaking itself, often due to external stimulus. In back-to-back papers published online, Rockefeller University scientists established possible new targets for drugs. First, PLD1 regulates the shuttling of beta-amyloid precursor protein beta-APP , a large molecule produced naturally in the body and found in many different cells, including brain cells.
It covers a variety of needs and interests. In general they now suspect that the affliction is really a host of conditions that tend to look alike at the macro level. But it probably stems from a host of causes, the brain having taken multiple assaults from external forces. And the wiring foul ups that cause it vary so widely that scans and other technical devices may show circuitry in far different parts of the brain are amiss from patient to patient.
The brain works as a unit. Everything is connected to everything else, and what we really need to be looking at more is abnormality in the circuitry level. As much as anybody, he can be credited as well with the creation of the modern computer.
He worked with the great theoretical physicist John von Neumann and the philosopher Ludwig Wittgenstein, an Austrian star at Cambridge. As we are discovering now in our neurological investigations, it is researchers such as Turing who can cross over many disciplines that best illuminate the complexities of the brain.
The chemical connections between neurons, called synapses, are thought to be critical to the formation of those networks and hence the laying down of memories.
In a group led by Thomas Arendt of the University of Leipzig in Germany showed that the number of synapses in the hippocampus, a brain structure crucial for learning and memory, falls during hibernation.
At the end of hibernation this protein clears away, and it is possible that the understanding of its comings and goings in the human brain would be helpful to understanding various disease mechanisms.
This site, and the sites it links to, also provide a reasonable picture of the organization of the brain. Is Singularity Upon Us? In Ubiquity , Ray Kursweil speculates that a better brain is close at hand: A thousand dollars of computation will equal the 10, trillion calculations per second that I estimate is necessary to emulate the human brain by The software side will take a little longer.
In order to achieve the algorithms of human intelligence, we need to actually reverse-engineer the human brain, understand its principles of operation. And there again, not surprisingly, we see exponential growth where we are doubling the spatial resolution of brain scanning every year, and doubling the information that we're gathering about the brain every year. Most objective observers realize that we really do not have a clue as to how anti-depressants work, that they do not work very well, and that they are very crude drugs that are used promiscuously.
The side effects are uncharted, and we have long been puzzled as to why it takes so long for them to kick in beneficially, although negative side effects often show up quickly. Now we are finally getting some hints as to how serotonin really gets activated:.
The energy levels of the fields were six times smaller than that of conventional cell phones and unlikely to harm healthy cells, the researchers say. The fibrils subsequently dissolved and remained dissolved for at least one week after being irradiated, indicating that the treatment was not only effective at breaking up the fibrils but also resulted in a lower tendency of the proteins to re-aggregate, according to the researchers.
Autopsies, however, show an amazing reduction in plaque. Schneider began to get her life back. Electrodes were surgically inserted in her brain and attached by wires to two pacemakers implanted in her chest…. Within eight weeks Ms. Movement disorders can result from a variety of stimuli, ranging from diseases to oxygen starvation to drug side effects. Perceptions here can be manipulated by expectations suggestions. Hypnosis has a long history, to include its uses for medical problems, but nobody quite ever has known how it works.
The subjects are primarily Dominicans, many from the Washington Heights neighborhood where the Taub is located. Late-onset is complex, stemming from a combination of genes, only one of which has been identified. Mayeux is involved with a host of neurological activities at Columbia as well. Such genius has long been associated with serious mental illness, especially schizophrenia and drug abuse. Drugs and Brain Rot To some extent, Nancy Andreasen works hard at telling us what we already sort of know.
Last Fall in the Times September 16, , p. That is, many conditions in the brain and elsewhere are due to accelerated deterioration. And drugs, by implication, are given out much too promiscuously. Andreasen had told us that she had moved her focus to creativity, but it is clear that she still has a hand in the schizophrenia game.
Airport screeners may miss target items when they are surrounded by other very similar items. As well, they also easily miss targets with slight variances from what they have in mind: Sadly, the site does not provide information on current research nor on how a lay person should evaluate the several medications being ladled out rather freely for such problems.
More restraint in their use seems to be indicated. Born Dualists Yale has many Blooms, but not many Roses. Paul Bloom is a Yale cognitive psychologist who believes that we come into this world making with a epistemological structure that distinguishes between body and soul from the get-go. Even if, in his own belief, they are just a continuum, not separate and alien parts of the human make-up. Says Bloom in Edge:. In the domain of bodies, most of us accept that common sense is wrong. We concede that apparently solid objects are actually mostly empty space, consisting of tiny particles and fields of energy.
Perhaps the same sort of reconciliation will happen in the domain of souls, and it will come to be broadly recognized that our dualist belief system, though intuitively appealing, is factually mistaken. But I am skeptical. The notion that our souls are flesh is profoundly troubling to many, as it clashes with religion.
Dualism and religion are not the same: You can be dualist without holding any other religious beliefs, and you can hold religious beliefs without being dualist. But they almost always go together. And some very popular religious views rest on a dualist foundation, such as the belief that people survive the destruction of their bodies. If you give up on dualism, this is what you lose.
The Anti-Depressants Not one peer-reviewed article really can link serotonin deficiency to any mental disorder. When you witness the hit and miss ways pharma-psychiatrists administer these drugs, you become aware that we are plagued with questions about drug effectiveness, side effects, and long term impact.
Xia Zhang at the University of Saskatchewan notes, however, that more research would be needed to see whether it could someday be used to treat depression in human beings. See SFN release on marijuana-like compounds , October 26, Nicotine may, in some instance, improve memory and counter certain diseases. In some experiments with rats, those treated with nicotine perform better on certain functions than a control group. His research established that hormones secreted from the brain's pituitary gland promote growth.
Walter Dandy, who succeeded Cushing, figured out in that air could be used to enable X-rays of the brain. His technique remained the best way to see into the skull to identify brain tumors and other problems until the invention of computer aided tomography CAT in Another 78 Hopkins faculty have secondary or joint appointments in neuroscience, including two dozen or so whose primary appointments are in the departments of Neurology, Neurosurgery or Psychiatry.
In the Department of Neurology, there are roughly 75 primary faculty, in the Department of Neurosurgery, The Department of Psychiatry, founded almost years ago, boasts full-time faculty with primary appointments.
Participants conduct simple mathematical calculations and read aloud passages from novels—activities that stimulate their frontal cortex and can prevent dementia. There are several efforts to test the efficacy of such elder age projects. Many people from ARF have moved over to this new endeavor. Somehow it seems ironic to read about a Schizophrenia social at a recent meeting of the Society for Neuroscience in Washington, but, one when gets over chuckling, one can only rejoice that this young group has a clear sense of community that will serve as a catalyst for the researchers it is abetting.
We are looking forward to getting on top of schizophrenia research trends. The researchers knew this because they had introduced a radioactive tracer that selectively binds to the same type of receptor in the brain, the mu-opioid variety, as the endorphins. More of the tracer was floating around unbound, suggesting the receptor sites were occupied by the endorphins.
Mrazek, chairman of psychiatry at Mayo. Gualberto Ruaho, president of Genomas , a company working on genetic tests for drug use. Some users of Paxil, for instance, have not been able to metabolize the drug satisfactorily, leading to toxic and sometimes fatal results. Mrazek of the Mayo Clinic said he used the tests to help choose antidepressants, particularly for children.
There has been concern that some children can turn suicidal or aggressive on antidepressants…. Few offer such genetic tests though the pharmacogenomics laboratory at the University of Louisville performed to in the last year.
We propose a research strategy to achieve this goal, and discuss its potential impact. The effects of developmental variations or abnormalities, traumatic brain injury, or neurodegenerative disease can all be captured as specific structural variants of the human connectome. As a physician and scientist, he had minutely researched the mechanical aspects of running and developed training procedures built around his knowledge of the body.
Read about his training methods at Nevada Track Stats. On the fiftieth anniversary of his run, the BBC asked him if the victory was the most significant event of his life.
He withdrew from private practice and limited himself to research after a serious auto accident which also ended his running. This was in , the year in which Queen Elizabeth knighted him. His other books include Fair Play. Psychiatry and the Auto-Immune System Serguei Fetissov of the Karolinska Institute in Sweden has tied the auto-immune system to anorexia nervosa and bulimia.
There is the suspicion that a host of mental disorders can arise from autoantibodies, which have gone astray and attacked human tissue. Of course, it has become awfully popular to blame a host of ailments on wayward immunity systems, another trend that is a bit overdone. Fetissov suggests that melanocortins that carry messages between nerve cells in the brain suffer from the assault. Such fits can currently be controlled only by drugs.
And, once bursting is suppressed this way, the neurons revert rapidly to normal behaviour. See The Economist , February 5, , p. All sorts of electro-simulative therapies are gaining currency. Toys to Diagnose Autism? In particular autistic children will gaze quite differently at robots than normal children. Robots for Stroke Victims MIT scientists have created a group of machines that help stroke victims regain mobility by retraining limbs and stimulating brain activity.
Professors Hogan and Krebs first introduced a machine in to help arm and shoulder movement. Interactive Motion Technologies Inc. See the Wall Street Journal , August 21, , p. Asthma and Stress Richard J. Subjects under stress demonstrated greater inflammation when inhaling allergens; brain scans suggest the stimulus may come from a specific part of the brain. See the New York Times , September 6, , p. T he Brain Marches on Two genes linked to brain size have evolved substantially over the last 60, years.
The finding is discussed by Bruce T. Lahn of the University of Chicago in Science. Apparently the report on these genes microcephalin and ASPM , known as alleles, also implies that their development has led to increased brain function, a claim generating much controversy.
In fact, it is not entirely clear that the genes relate either to brain size or cognitive function, and there may be other genes related to size in certain populations lacking these particular genes.
See the New York Times , September 9, , p. Seeing, Hearing, and Smelling the World The Howard Hughes Medical Institute has cleverly put a simple little primer about the senses on its website www. Other foundations and government agencies should take note, particularly those involved with neuroscience. This is an outstanding way to bring an out-of-the-way institution to the notice of the general public. See Biospectral Index technology at www. We are not entirely clear how well the Society for Neuroscience, created in to knit together neurologists in the States, meshes its activities with the global body.
Spices and Rotten Odors Kensaku Mori and colleagues at the University of Tokyo have deciphered how spices cover up the smell of spoiled foods with neural help from the brain.
Apparently both the rotten foods and the spices activate the same olfactory bulb—at least amongst the rats with which they experimented. The average human nose can detect nearly 10, distinct scents, a feat that requires about 1, olfactory genes, or roughly 3 per cent of the human genome. If that works, they plan to use future, more powerful computers to link such simulated columns together into something that mimics a brain.
Pierce Laboratory, and University of Dresden … got 11 volunteers to lie inside magnetic brain scanners with separate straws leading to the fronts of their noses … and the back above the palate.
Dana Small of the Yale team said it suggested that the brain changed smell perceptions based on eating…. See the New York Times , August 23, , p. See The Economist , July 30, , p. Of course, now the thesis has to be proven. H eart and Mind The things you do to avoid heart disease and cancer also help keep your brain in high gear. Her nostrums include eating right, staying socially connected, and keeping mentally active: The close interrelationship between the two suggests that brain mood can strongly affect digestion, and, in turn, the digestive process has side effects in brain process.
Langley, a British physician who believed that it was one of three parts … of the automatic nervous system, which controls involuntary behaviors like breathing and circulation. Gershon revived his thinking and was widely mocked at first. To learn about Langley and receptors, see www.
In this case, it is too much serotonin rather than too little. Centralization in computerdom not only creates overload but it makes the system very vulnerable to attacks from outside agents. Essays in Cognitive Psychology. Basically data unconsciously imprinted on the brain at some point can make a scene or experience seem very familiar at a later date, even if one has not really encountered the scene or experience before.
McGregor styles the title of the hourlong production he has made for his Random Dance, a resident troupe at Sadlers Wells. McGregor and a handful of neuroscientists from the department of experimental psychology at Cambridge University.
To learn about Ataxia, see www. A Drink a Day A study shows that a drink or day or less helps prevent cognitive decline in women. Moderate drinkers fared better than heavy drinkers, or those who did not drink at all.
See the Wall Street Journal , January 20, , p. The nurses had been tracked for a number of health issues since , though this particular study ran from with a follow-up two years later. BPA plastics are widely used in a variety of drinking liquid containers, some 6 billion pounds of BPA produced annually. For further details on the research, see http: In this particular study, those who were brain damaged demonstrated an absence of fear, avoiding the risk averse behavior shown by the normal range of human beings Wall Street Journal , July 21, , pg.
This article expands on the growing body of theory in behavioral economics and neuroeconomics. Previously, in other risk and decision studies, psychologists have revealed that we tend to use different parts of our brain for near-term and long-term decisions, with emotion often coming more into play for matters involving some immediacy. Of course, we always knew that bankers, hedge fund operators, and actuaries had too much ice water in their veins. All this seems to have been put together by an aggressive attorney at something called the Brain Injury Law Office.
You can learn more about Attorney Johnson and his sites at http: His glossary of terms is helpful to an initiate www. For more Brain-Made-Simple type information, see http: We will feel fear, for instance, when we sense it in others, because of our empathy cells. This further raises the question of where one can feel and anticipate what others are thinking about.
However, scientists in the Bay Area have an opposing view of how such diseases came about. Askkenazi in the West e. Jews historically have been driven into high intelligence occupations, and they have suffered from inbreeding. Hormone Bolsters Trust Scientists have long known that oxytocin, present in the body during childbirth and lactation, creates close feelings and mating among sundry mammals.
Ernest Fehr, an economist at the University of Zurich and lead author on a paper from a research team there, thinks the hormone may help those who are pathologically distrustful. Using students, the researchers tested the inclination to make investments in an experimental game. Those inhaling oxytocin, on average, invested 17 percent more than those in a placebo group, and 45 percent of the inhalers invested all their money, as opposed to 21 percent in the control group.
The practical implications in terms of future treatments is still unclear. See the New York Times , June 2, ; http: The drug, D-cycloserine, an antibiotic, does nothing to soothe panic or calm nerves.
Instead, it increases learning and memory, and may help people overcome their fears faster…. D-cycloserine is known to act on these receptors…. See the New York Times , March 22, , p. See Fortune Small Business , May , p. More on Nerve Regeneration Though all our biology tests say nerves cannot be regenerated, we keep finding examples to the contrary. Now the Schepens Eye Research Institute www. Next, it wants to see how much vision was restored as a consequence.
See Business Week , March 21, , p. That word is … stop. Dail and Robert W. The brain apparently requires a consolidation period to fasten connections between neurons in the brain where the exercise pattern becomes implanted. Mental Health Portal This portal of the National Institutes of Health provides numerous links to mental health resources as well as posting current bits of news in the mental health field www.
You do have to know what you are looking for, though, because it is just a collection, and it does not highlight more significant developments. All About Autism In our Letters section, we review the state of our knowledge about autism. Despite all the shouting, we still know extremely little about it.
Further, we suspect the scientific community is not looking hard enough for the environmental factors that probably lie behind the surge in cases amongst newborns. The authors suggest using rather concrete biological instead of behavioral criteria for autism.
This suggests that there is something deficient in language perception. The Many Fathers of Neoroscience Just like good ideas, and the earthly children of the gods, neuroscience can claim a host of fathers, with nobody having an absolute claim on its paternity.
We will cast our votes for a couple of fellows here. He did considerable work with cholera, tetanus, and diphtheria, was a philosopher, and a poet as well. He won the Nobel Prize in http: But we could easily choose Santiago Ramon y Cajal. Starting off in artistic directions, he eventually made his way into science. Using and improving on a silver nitrate staining technique from the Italian Golgi, he did conclusive studies in Barcelona that led to his definitive proof of neuron theory in Cajal and Golgi shared the Nobel Prize in Like Sherrington, he made a multitude of contributions to the field.
It is impressive that Sherrington and Cajal made so many discoveries in neuroscience but that their interests and contributions ranged well beyond neuroscience. Generalists seem to outdo specialists at every turn. See the Wall Street Journal , March 29, , pp. Increasingly, mental disability is becoming cultural grist for writers, dramatists, and others in the arts. Tony Shalhoub, the taxi driver in the show about Nantucket called Wings, which is now in rerun, has starred for several seasons in a very successful TV series featuring an insightful detective named Monk with obsessive compulsive behavior.
Neurological disorders are slowly moving to center stage in our society. R ewiring the Body Business Week March 7, , pp.
Alan Brown at Columbia University is probing the connections between flu in pregnancy and subsequent schizophrenic offspring. Ian Lipkin and Norwegian researchers are looking at the relationship between viruses and autism, as well as looking for other autism causes. The use of botox botulinum toxin has temporarily frozen muscle groups associated with tics, the effect lasting several months. Electrodes for Depression Deep-brain stimulation is also being used in other settings.
Toronto Western Hospital in Canada has a pilot study going. The work is based on the discovery by Dr. Of the million people worldwide taken to be depression afflicted, a quarter, give or take, do not respond to any treatment, the electrode and battery implant being a godsend. See The Economist , March 5, , pp. Also see Neuron, www. In some children, OCD waxes and wanes with the onset or departure of strep infections. The term Pandas was coined by Dr. We have previously noted that there is a small but vocal fraternity that believes there is a direct connection between physical illnesses of various sorts and such disorders as autism and obsessive compulsive disorder in items and in the original entry above.
We ourselves believe there is much to be gained by much more research on the part bacterial and viral infections and environmental influences play in a host of conditions.
This line of thinking is slipping into the mainstream with the New York Times Magazine May 22, , pp. Swedo at the National Institute of Mental Health whom we mentioned previously. In general researchers are pretty well defended against theses that promote infectious or chemical bases of OCD and other conditions.
So far the biggest impetus for a broader national effort on autism has come from grassroots initiatives on the part of affected parents and relatives. Learn more about the autism specials in these webpages: Ashley Bush of Australia has pursued that line of investigation.
See more on Bush on Brain Stem. A fairly reasonable article on the debate can be found in the Seattle Times at www.
Usually those who connect up autism with mercury believe the problem arises in vaccinations, especially spray type vaccines www0. Mainstream thinking generally is scornful of any linkage between mercury, metals, etc. By and large, most research is pursuing a genetic basis for both conditions, and yet that does not seem to offer a good enough explanation of the rising incidence of these diseases. The chemical basis of many neurological conditions probably deserves greater funding and focus.
Unfortunately neurological investigators generally lack any real grounding in biochemistry. For more on the connection between vaccines and autism, see Stitch in Time. In her thirties she began to find that her mind was just not clicking in the same way.
Just before she turned 45, she realized that she had forgotten the title of a film plus more that she had just seen with her husband. She went to see Dr. Enrolling in a study he was doing, she found out that she had average memory impairment for her age. After tests for deterioration and various attempts to sharpen the memory, she discovered in fact that her loss was not so much due to brain degeneration but to brain damage suffered much earlier in life.
Talking with her brother, she uncovered a number of early whacks she took on the head that probably accounted for her later impairment. It is more common than is realized for early concussive effects to show up in later brain impairment, so, signally, much breakdown we attribute to age is actually due to events that occurred much earlier in life.
Adderall immediately brought new focus to her brain, but found that it simultaneously dulled some aspects of life, taking away some of the mental twists and turns she commonly enjoyed. C holine Choline, a vitamin B-like compound, is found to be a critical ingredient in embryonic brain development. In high demand by the fetus during pregnancy, the mother may not have adequate supplies during that stage. To this end, eggs, meat, milk are critical diet elements for pregnant women.
It helps form a neurotransmitter as well as aiding in critical brain cell subdivision. Choline, along with folic acid, therefore, plays a key role in avoiding birth defects. Your Brain and the Neuroscience of Everyday Life. From a review in The Guardian , May 15, One joint study involves Kronos Science Laboratories www. The joint study will examine blood and brain tissue from 1, known to have had the disease, comparing results to 1, who have not had disease.
Focus on Brain Growth and Inflammation At an autism summit held in Malibu under auspices of Cure Autism Now Foundation, sundry neuroscientists claimed a more coherent picture of autism development is now emerging. Infants and toddlers move their bodies differently. From 6 months to 2 years, their heads grow much too fast. Parts of their brain have too many connections, while other parts are underconnected…. Moreover, their brains show signs of chronic inflammation in the same areas that show excessive growth.
The inflammation appears to last a lifetime. By 2 years, excessive white matter is found in the frontal lobes, the cerebellum and association areas, where higher-order processing occurs. In large part, the circuitry is just not working right, with local areas over-connected, and long-range networks under-connected.
A utism and Allergies Kaiser Permanente research looking at data on 88, children show mothers suffering from asthma, allergies, or certain types of skin disease notably psoriasis have a higher risk of giving birth to an autistic child. The study, published in the Archives of Pediatrics and Adolescent Medicine, wonders if there is common genetic basis for allergy and autism which would explain the linkage.
In summer , it is expected to sell the first of five versions. Reputedly it will also publish research documenting results in early See Fortune Small Business , Dec.
First, he finds himself infatuated with the amygdala, not because it is the seat of fear and emotion named after the Greek word for almond, but simply because he likes the ring of the word. He is taken, too, with the idea of earworms which are tunes that lodge themselves in our heads and play over and over again: But it can also harm the ability to hear and produce melody. He wonders if they both do not stem from lesions in some common part of the brain.
Yet you can have one complaint without the other—good in speech and horrible in music, good in music and defective in speech. The amygdala has nothing to do with aphasia or amusia, but his very fixation with the word reminds him humorously of the tangled web many lesion sufferers weave with words and music. De-plaquing When amyloid beta peptide plaque was removed from the brains of mice, nerve cells lost their swelling and regained their normal structure.
Gene-Jack Wang is using positron-emissions tomography to study over-eaters. There is sundry research afoot to see if various drugs can turn off brain centers that support appetite.
Lawyers are following the research, aware that the trail of data may create culpability for food companies if certain ingredients like fat and sugar are found to stimulate neural processes that lead to excessive appetite. Forbes , January 10, , pp. See The Economist , December 4, , pp. The lingo of this trade has always and still is subject to such imprecision that different practitioners commonly, throughout the 20 th century, have rendered different diagnoses at the same time when looking at one patient, or when looking at a group of patients with roughly the same symptoms.
The DSM Diagnostic and Statistical Manual of Mental Disorders came along in , but only when Robert Spitzer out of Columbia took over as its director did this volume achieve any rigor or wide respect. Nonetheless, Spitzer by what he wrote and by what he rejected deeply shaped the psychiatric field during the latter half of the 20th century. When he took on the DSM, nobody wanted the job.
Spitzer brought a little commonsense to disease nomenclature, which is an achievement in itself when you consider that several of the chieftains in this trade are impractical, fuzzy headed, and even a little mad. Neurons at the Wheel Rat neurons on top of a multi-electrode array have been hooked up to a desktop computer and a flight simulator to control vertical and horizontal movements of the simulated aircraft.
This is an outgrowth of work done on the Animat project with Steve Potter www. For more on Animat, see www. A leading company in the field is Memory Phamaceuticals, headed by Nobel prize winner Eric Kandel, who has long studied memory and learning with the help of Aplysia, a big sea slug whose neurons are easy to study. His company, as well as Helicon Therapeutics, is working on compounds that makes neural pathways work better. Marc Caron and Dr.
High levels of serontin lead to better moods, and often, lower production is associated with sour moods and depression. However, we always urge researchers to carefully scrutinize results coming out of the Duke facility. If the results hold up, this gene TPH2 difficulty may explain why certain patients with depression symptoms do not respond to drug treatment, since there seems to be a correlation between those with this particular defect and those for whom serontin-inducers are ineffective.
See also the Wall Street Journal , December 10, , p. Brain Scans Gone Crazy We have already cited numerous studies based on brain scans—functional magnetic-resonance imaging. And when viewing the opposition, all had increased blood flow in the region where humans consciously assert control over emotions…. B1 reports that brain scans employing functional magnetic resonance imaging reveal that monks with a history of intense meditation over 10, hours show much higher rates of high-frequency brain activity.
T he Biology of Autism Dr. Marcel Just of Carnegie Mellon and Dr. Just posits that there is less connectivity in the brains of autistic persons. See The Economist , August 7, , p. The article cited is in the August issue of Brain see www. The Stylish Neurologist The very well decked out Dr. Clearly the sight of her puts more bounce in the step of patient and doctor alike. When you go up to visit the medicine men in Boston, we recommend a trip along Newbury Street in any event—to get away from it all.
Chances are you will meet some doctors of all trades similarly escaping from the studied seriousness that afflicts Boston. Boston Scientific, big in the drug-coated stent business and in other aspects of cardiology, has already paid up for a chunk of the company. See Business Week , October 2, , p.
Loosely the whole site deals with artificial intelligence and various efforts to look at intelligence and to simulate consciousness. We particularly enjoyed the section on How to Build a Brain. Probably the way to survey the articles here is to look at the author listing at www. Chudler has taken several days off from brain research and other weighty endeavors to construct a page of jokes and other amusing stuff for kids.
You will want to learn, for instance, what the right hemisphere of the brain said to the left when they could not agree on anything. Autism Website for Parents One of our readers, the parent of an autistic child, has found two websites quite useful. First, the Autism Research Institute at www. Trials in rats, as well as come in human beings, have sometimes resulted in improvement.
We had previously commented on this in Item To be sure, this is still a primitive field in which you have to be chary of the practitioners: Apparently Gerry Zaltman of Harvard got the neuro-ball rolling towards the end of the 20th century. Brighthouse Neurostrategies Group in Atlanta ran with it, looking at consumer preferences in conjunction with Emory University, but not dealing with specific products or advertising tactics.
The surging incidence of autism in America baffles the medical establishment. The causes are not well understood. The condition stems from neurological abnormalities in the brain, which show up as cognitive and sensory disorders in a child. Something as basic as forced eye contact or the presence of strangers can trigger sensory overload.
Auditory processing deficiencies mean the child may have trouble understanding even the purpose of speech. Thinking in Pictures , by Temple Grandin Vintage, , is an autism classic. This delightful, insightful book does not provide all the answers to the mysteries of autism.
Rather, the autistic author illuminates the mind, behavior and outlook on the world of the autistic. Oliver Sacks writes in his elegant foreword: Grandin is a world-famous expert on cattle psychology and behavior.
A third of all cattle and hogs in the U. Grandin deploys superior visual spatial skills, which she describes as resembling a video library or computer graphics program in her imagination and memory many autistics have heightened visual abilities for reasons not well understood.
A change in a daily routine can cause an autistic person to have a tantrum…I have often observed that the senses of some people with autism resemble the acute senses of animals. The book provides many insights into animal behavior. Indeed, Grandin seems more comfortable with her animal friends than with homo sapiens. Teaching a person with autism the social graces is like coaching an actor for a play. Every step has to be planned…. When people are responding to each other with emotion rather than intellect, I need to have long discussions with friends who can serve as translators.
There appear to be genetic links between autism and the depression, anxiety disorder and schizophrenia often found in artists, poets, and creative writers.
The results were published in the May issue of the Archives of Neurology. Other small collateral studies have reached the same conclusion. Apparently, it is thought, reduced use of insulin present in the brain leads to the same plaque build-up often found in brains of. His results were published in The Archives of Neurology in Read about Wolozin and his work on sundry brain diseases at www.
The thought is that excess cholesterol, high blood pressure, etc. According to this idea, the disease is caused by the accumulation of sticky plaques made of beta-amyloid. Yet rat brains injected with beta-amyloid, Dr. However, scientists with alternate theories are having a hard time getting published in prestige journals such as Science or Nature. We ourselves know of one significant researcher who has been turned down on 11 grants over the last year. Of course, this is not the first time dominant, wrong-headed theories have impeded promising research, but it is useful to note that our highly centralized funding processes, subject as they are to narrow ideologues, are significantly flawed, not always distributing funds to the best advantage.
He died on September 26, at age 54, probably from love. Of course, this bacterium is very common, so the link may prove tenuous. See The Economist , March 20, , pp. Roughly, he thinks plaque and the metals interact to produce brain deterioration.
Now a firm called Prana is trying to commercialize his ideas, believing it has a drug in development that will go right to the heart of the disease. Since we believe researchers are generally chasing down blind alleys in their pursuit of the causes and cure of the disease, we are fascinated with these developments down under.
The Aussies discovered the cause of ulcers while researchers in the U. So far this work has reversed the disease in mice: The problem is that there is only a brief period in which a drug could be effective in any event. Most strokes are ischemic, caused by a clot that temporarily blocks blood flow to part of the brain.
The damage spreads fast over 5 or 6 hours, unless there is a rapid intervention. Paion in Germany is working on a good clot buster. The other approach being attempted by Pfizer, Ono in Japan, and an AstraZeneca-Renovis partnership is to uncover an agent that will insulate nerve cells against damage by trapping free radicals. Cerovive, from the latter, is the most rigorously tested thus far.
See Forbes , March 29, , pp. Commentators feel, however, that both approaches only amount to partial solutions and that a multifaceted attack will have to be staged on strokes as they occur. Spinal Cord Cell Regeneration Dr. D3 , talked about nerve cell regeneration in the case of spinal cord injuries.
The axons of damaged cells may have a hard time repairing themselves partially because of myelin. As a neurologist, he has dealt with a host of brain diseases firsthand, and here you will find an extensive bibliography, audios, etc.
As well, this is just about as good a website as you find for any author: It not only has plentiful detail, but it is beautifully designed, right down to the typefaces. Such aesthetic care is almost universally lacking in all the sites we encounter, even those with heavy financial backing. Only the homepage, which is pretty but not intuitive, is awkward, but once you get past it, the site is a thing of beauty. This is all to say that Sacks clearly understands the link between science and art.
We are learning in all fields, from business to medicine, that understanding flows not only from quantitative data but from narratives that capture every stray fact. Stories or histories will tell us as much or more than bits of data.
Again and again, it seems, those lucky enough to be fine writers often make better investigators than their colleagues. Sacks can look at neurons, but he also tells the story of patients that may reveal aspects of how a disease works.
As well, he probes his own history to understand memory and other aspects of the psyche. Even books about fern collecting expeditions, such as his Oaxaca Journal , occasionally delve back into his childhood, which is never far from his mind. Janet Frame It is not only neurologists and scientists who are helped by putting pen to paper. Janet Frame, of New Zealand, just died on January 29, , after a trying lifetime of mental illness.
Institutionalized at 21 and subject to all the dreadful treatments such as electro-shock that have been attempted with very troubled patients, she was only saved from lobotomy because her fine writing surfaced and her surgeon was moved to let well enough alone. Later she was to write Faces in the Water , clearly an autobiographical novel, at the urging of a London psychiatrist. Fortunately, her writing not only saved her from the knife, but it was also therapeutic in a way that neither analysis nor drugs could ever be.
We probably never will fully understand why soulful expression plays such a part in the relief of all sorts of illness, mental and otherwise. The brains of vertebrates are made of very soft tissue. Vertebrate brains are surrounded by a system of connective tissue membranes called meninges that separate the skull from the brain.
Blood vessels enter the central nervous system through holes in the meningeal layers. The cells in the blood vessel walls are joined tightly to one another, forming the blood—brain barrier , which blocks the passage of many toxins and pathogens  though at the same time blocking antibodies and some drugs, thereby presenting special challenges in treatment of diseases of the brain.
Neuroanatomists usually divide the vertebrate brain into six main regions: Each of these areas has a complex internal structure. Some parts, such as the cerebral cortex and the cerebellar cortex, consist of layers that are folded or convoluted to fit within the available space.
Other parts, such as the thalamus and hypothalamus, consist of clusters of many small nuclei. Thousands of distinguishable areas can be identified within the vertebrate brain based on fine distinctions of neural structure, chemistry, and connectivity. Although the same basic components are present in all vertebrate brains, some branches of vertebrate evolution have led to substantial distortions of brain geometry, especially in the forebrain area.
The brain of a shark shows the basic components in a straightforward way, but in teleost fishes the great majority of existing fish species , the forebrain has become "everted", like a sock turned inside out. In birds, there are also major changes in forebrain structure. Here is a list of some of the most important vertebrate brain components, along with a brief description of their functions as currently understood:. The most obvious difference between the brains of mammals and other vertebrates is in terms of size.
On average, a mammal has a brain roughly twice as large as that of a bird of the same body size, and ten times as large as that of a reptile of the same body size. Size, however, is not the only difference: The hindbrain and midbrain of mammals are generally similar to those of other vertebrates, but dramatic differences appear in the forebrain, which is greatly enlarged and also altered in structure.
In non-mammalian vertebrates, the surface of the cerebrum is lined with a comparatively simple three-layered structure called the pallium. In mammals, the pallium evolves into a complex six-layered structure called neocortex or isocortex.
The elaboration of the cerebral cortex carries with it changes to other brain areas. The superior colliculus , which plays a major role in visual control of behavior in most vertebrates, shrinks to a small size in mammals, and many of its functions are taken over by visual areas of the cerebral cortex.
The brains of humans and other primates contain the same structures as the brains of other mammals, but are generally larger in proportion to body size. It takes into account the nonlinearity of the brain-to-body relationship. Dolphins have values higher than those of primates other than humans,  but nearly all other mammals have EQ values that are substantially lower. Most of the enlargement of the primate brain comes from a massive expansion of the cerebral cortex, especially the prefrontal cortex and the parts of the cortex involved in vision.
It has been estimated that visual processing areas occupy more than half of the total surface of the primate neocortex. It takes up a much larger proportion of the brain for primates than for other species, and an especially large fraction of the human brain. The brain develops in an intricately orchestrated sequence of stages. Neurons are created in special zones that contain stem cells , and then migrate through the tissue to reach their ultimate locations.
Once neurons have positioned themselves, their axons sprout and navigate through the brain, branching and extending as they go, until the tips reach their targets and form synaptic connections. In a number of parts of the nervous system, neurons and synapses are produced in excessive numbers during the early stages, and then the unneeded ones are pruned away.
For vertebrates, the early stages of neural development are similar across all species. The neural plate folds inward to form the neural groove , and then the lips that line the groove merge to enclose the neural tube , a hollow cord of cells with a fluid-filled ventricle at the center. At the front end, the ventricles and cord swell to form three vesicles that are the precursors of the forebrain , midbrain , and hindbrain.
At the next stage, the forebrain splits into two vesicles called the telencephalon which will contain the cerebral cortex, basal ganglia, and related structures and the diencephalon which will contain the thalamus and hypothalamus.
At about the same time, the hindbrain splits into the metencephalon which will contain the cerebellum and pons and the myelencephalon which will contain the medulla oblongata. Each of these areas contains proliferative zones where neurons and glial cells are generated; the resulting cells then migrate, sometimes for long distances, to their final positions. Once a neuron is in place, it extends dendrites and an axon into the area around it.
Axons, because they commonly extend a great distance from the cell body and need to reach specific targets, grow in a particularly complex way. The tip of a growing axon consists of a blob of protoplasm called a growth cone , studded with chemical receptors. These receptors sense the local environment, causing the growth cone to be attracted or repelled by various cellular elements, and thus to be pulled in a particular direction at each point along its path.
The result of this pathfinding process is that the growth cone navigates through the brain until it reaches its destination area, where other chemical cues cause it to begin generating synapses.
Considering the entire brain, thousands of genes create products that influence axonal pathfinding. The synaptic network that finally emerges is only partly determined by genes, though. In many parts of the brain, axons initially "overgrow", and then are "pruned" by mechanisms that depend on neural activity. In the first stages of development, each axon from the retina is guided to the right general vicinity in the midbrain by chemical cues, but then branches very profusely and makes initial contact with a wide swath of midbrain neurons.
The retina, before birth, contains special mechanisms that cause it to generate waves of activity that originate spontaneously at a random point and then propagate slowly across the retinal layer. These waves are useful because they cause neighboring neurons to be active at the same time; that is, they produce a neural activity pattern that contains information about the spatial arrangement of the neurons.
This information is exploited in the midbrain by a mechanism that causes synapses to weaken, and eventually vanish, if activity in an axon is not followed by activity of the target cell. The result of this sophisticated process is a gradual tuning and tightening of the map, leaving it finally in its precise adult form. Similar things happen in other brain areas: In some cases, as with the retina-midbrain system, activity patterns depend on mechanisms that operate only in the developing brain, and apparently exist solely to guide development.
In humans and many other mammals, new neurons are created mainly before birth, and the infant brain contains substantially more neurons than the adult brain. The two areas for which adult neurogenesis is well established are the olfactory bulb, which is involved in the sense of smell, and the dentate gyrus of the hippocampus, where there is evidence that the new neurons play a role in storing newly acquired memories.
With these exceptions, however, the set of neurons that is present in early childhood is the set that is present for life. Glial cells are different: There has long been debate about whether the qualities of mind , personality, and intelligence can be attributed to heredity or to upbringing—this is the nature and nurture controversy.
Genes determine the general form of the brain, and genes determine how the brain reacts to experience. Experience, however, is required to refine the matrix of synaptic connections, which in its developed form contains far more information than the genome does. In some respects, all that matters is the presence or absence of experience during critical periods of development.
The functions of the brain depend on the ability of neurons to transmit electrochemical signals to other cells, and their ability to respond appropriately to electrochemical signals received from other cells. The electrical properties of neurons are controlled by a wide variety of biochemical and metabolic processes, most notably the interactions between neurotransmitters and receptors that take place at synapses.
Neurotransmitters are chemicals that are released at synapses when an action potential activates them—neurotransmitters attach themselves to receptor molecules on the membrane of the synapse's target cell, and thereby alter the electrical or chemical properties of the receptor molecules.
With few exceptions, each neuron in the brain releases the same chemical neurotransmitter, or combination of neurotransmitters, at all the synaptic connections it makes with other neurons; this rule is known as Dale's principle.
The great majority of psychoactive drugs exert their effects by altering specific neurotransmitter systems. This applies to drugs such as cannabinoids , nicotine , heroin, cocaine , alcohol, fluoxetine , chlorpromazine , and many others. The two neurotransmitters that are used most widely in the vertebrate brain are glutamate , which almost always exerts excitatory effects on target neurons, and gamma-aminobutyric acid GABA , which is almost always inhibitory.
Neurons using these transmitters can be found in nearly every part of the brain. Some general anesthetics act by reducing the effects of glutamate; most tranquilizers exert their sedative effects by enhancing the effects of GABA.
There are dozens of other chemical neurotransmitters that are used in more limited areas of the brain, often areas dedicated to a particular function.
Serotonin , for example—the primary target of antidepressant drugs and many dietary aids—comes exclusively from a small brainstem area called the raphe nuclei. As a side effect of the electrochemical processes used by neurons for signaling, brain tissue generates electric fields when it is active. When large numbers of neurons show synchronized activity, the electric fields that they generate can be large enough to detect outside the skull, using electroencephalography EEG  or magnetoencephalography MEG.
EEG recordings, along with recordings made from electrodes implanted inside the brains of animals such as rats, show that the brain of a living animal is constantly active, even during sleep. In mammals, the cerebral cortex tends to show large slow delta waves during sleep, faster alpha waves when the animal is awake but inattentive, and chaotic-looking irregular activity when the animal is actively engaged in a task.
During an epileptic seizure , the brain's inhibitory control mechanisms fail to function and electrical activity rises to pathological levels, producing EEG traces that show large wave and spike patterns not seen in a healthy brain. Relating these population-level patterns to the computational functions of individual neurons is a major focus of current research in neurophysiology.
All vertebrates have a blood—brain barrier that allows metabolism inside the brain to operate differently from metabolism in other parts of the body. Glial cells play a major role in brain metabolism by controlling the chemical composition of the fluid that surrounds neurons, including levels of ions and nutrients. Brain tissue consumes a large amount of energy in proportion to its volume, so large brains place severe metabolic demands on animals.
The need to limit body weight in order, for example, to fly, has apparently led to selection for a reduction of brain size in some species, such as bats. Information from the sense organs is collected in the brain. There it is used to determine what actions the organism is to take. The brain processes the raw data to extract information about the structure of the environment. Next it combines the processed information with information about the current needs of the animal and with memory of past circumstances.
Finally, on the basis of the results, it generates motor response patterns. These signal-processing tasks require intricate interplay between a variety of functional subsystems. The function of the brain is to provide coherent control over the actions of an animal. A centralized brain allows groups of muscles to be co-activated in complex patterns; it also allows stimuli impinging on one part of the body to evoke responses in other parts, and it can prevent different parts of the body from acting at cross-purposes to each other.
The human brain is provided with information about light, sound, the chemical composition of the atmosphere, temperature, head orientation, limb position, the chemical composition of the bloodstream, and more.
In other animals additional senses are present, such as the infrared heat-sense of snakes, the magnetic field sense of some birds, or the electric field sense of some types of fish.
Each sensory system begins with specialized receptor cells,  such as light-receptive neurons in the retina of the eye, or vibration-sensitive neurons in the cochlea of the ear. The axons of sensory receptor cells travel into the spinal cord or brain, where they transmit their signals to a first-order sensory nucleus dedicated to one specific sensory modality. This primary sensory nucleus sends information to higher-order sensory areas that are dedicated to the same modality.
Eventually, via a way-station in the thalamus , the signals are sent to the cerebral cortex, where they are processed to extract the relevant features, and integrated with signals coming from other sensory systems. Motor systems are areas of the brain that are involved in initiating body movements , that is, in activating muscles.
Except for the muscles that control the eye, which are driven by nuclei in the midbrain, all the voluntary muscles in the body are directly innervated by motor neurons in the spinal cord and hindbrain. The intrinsic spinal circuits implement many reflex responses, and contain pattern generators for rhythmic movements such as walking or swimming.
The descending connections from the brain allow for more sophisticated control. The brain contains several motor areas that project directly to the spinal cord. At the lowest level are motor areas in the medulla and pons, which control stereotyped movements such as walking, breathing, or swallowing. At a higher level are areas in the midbrain, such as the red nucleus , which is responsible for coordinating movements of the arms and legs.
At a higher level yet is the primary motor cortex , a strip of tissue located at the posterior edge of the frontal lobe. The primary motor cortex sends projections to the subcortical motor areas, but also sends a massive projection directly to the spinal cord, through the pyramidal tract. This direct corticospinal projection allows for precise voluntary control of the fine details of movements.
Other motor-related brain areas exert secondary effects by projecting to the primary motor areas. Among the most important secondary areas are the premotor cortex, basal ganglia, and cerebellum. In addition to all of the above, the brain and spinal cord contain extensive circuitry to control the autonomic nervous system , which works by secreting hormones and by modulating the "smooth" muscles of the gut. Many animals alternate between sleeping and waking in a daily cycle.
Arousal and alertness are also modulated on a finer time scale by a network of brain areas. A key component of the arousal system is the suprachiasmatic nucleus SCN , a tiny part of the hypothalamus located directly above the point at which the optic nerves from the two eyes cross. The SCN contains the body's central biological clock. Neurons there show activity levels that rise and fall with a period of about 24 hours, circadian rhythms: The SCN continues to keep time even if it is excised from the brain and placed in a dish of warm nutrient solution, but it ordinarily receives input from the optic nerves, through the retinohypothalamic tract RHT , that allows daily light-dark cycles to calibrate the clock.
The SCN projects to a set of areas in the hypothalamus, brainstem, and midbrain that are involved in implementing sleep-wake cycles. An important component of the system is the reticular formation , a group of neuron-clusters scattered diffusely through the core of the lower brain.
Reticular neurons send signals to the thalamus, which in turn sends activity-level-controlling signals to every part of the cortex. Damage to the reticular formation can produce a permanent state of coma. Sleep involves great changes in brain activity. There are two types of sleep: Three broad types of distinct brain activity patterns can be measured: During deep NREM sleep, also called slow wave sleep , activity in the cortex takes the form of large synchronized waves, whereas in the waking state it is noisy and desynchronized.
Levels of the neurotransmitters norepinephrine and serotonin drop during slow wave sleep, and fall almost to zero during REM sleep; levels of acetylcholine show the reverse pattern. For any animal, survival requires maintaining a variety of parameters of bodily state within a limited range of variation: The basic principle that underlies homeostasis is negative feedback: In vertebrates, the part of the brain that plays the greatest role is the hypothalamus , a small region at the base of the forebrain whose size does not reflect its complexity or the importance of its function.
Some of these functions relate to arousal or to social interactions such as sexuality, aggression, or maternal behaviors; but many of them relate to homeostasis.
Several hypothalamic nuclei receive input from sensors located in the lining of blood vessels, conveying information about temperature, sodium level, glucose level, blood oxygen level, and other parameters. These hypothalamic nuclei send output signals to motor areas that can generate actions to rectify deficiencies. Some of the outputs also go to the pituitary gland , a tiny gland attached to the brain directly underneath the hypothalamus.
The pituitary gland secretes hormones into the bloodstream, where they circulate throughout the body and induce changes in cellular activity. The individual animals need to express survival-promoting behaviors, such as seeking food, water, shelter, and a mate. The motivational system works largely by a reward—punishment mechanism. When a particular behavior is followed by favorable consequences, the reward mechanism in the brain is activated, which induces structural changes inside the brain that cause the same behavior to be repeated later, whenever a similar situation arises.
Conversely, when a behavior is followed by unfavorable consequences, the brain's punishment mechanism is activated, inducing structural changes that cause the behavior to be suppressed when similar situations arise in the future. Most organisms studied to date utilize a reward—punishment mechanism: Rewards and punishments function by altering the relationship between the inputs that the basal ganglia receive and the decision-signals that are emitted.
The reward mechanism is better understood than the punishment mechanism, because its role in drug abuse has caused it to be studied very intensively. Research has shown that the neurotransmitter dopamine plays a central role: Almost all animals are capable of modifying their behavior as a result of experience—even the most primitive types of worms.
Because behavior is driven by brain activity, changes in behavior must somehow correspond to changes inside the brain. Already in the late 19th century theorists like Santiago Ramón y Cajal argued that the most plausible explanation is that learning and memory are expressed as changes in the synaptic connections between neurons. Neuroscientists currently distinguish several types of learning and memory that are implemented by the brain in distinct ways:.
The field of neuroscience encompasses all approaches that seek to understand the brain and the rest of the nervous system. The brain is also the most important organ studied in psychiatry , the branch of medicine that works to study, prevent, and treat mental disorders. The oldest method of studying the brain is anatomical , and until the middle of the 20th century, much of the progress in neuroscience came from the development of better cell stains and better microscopes.
Neuroanatomists study the large-scale structure of the brain as well as the microscopic structure of neurons and their components, especially synapses. Among other tools, they employ a plethora of stains that reveal neural structure, chemistry, and connectivity.
In recent years, the development of immunostaining techniques has allowed investigation of neurons that express specific sets of genes. Also, functional neuroanatomy uses medical imaging techniques to correlate variations in human brain structure with differences in cognition or behavior. Neurophysiologists study the chemical, pharmacological, and electrical properties of the brain: Thousands of experimentally developed drugs affect the nervous system, some in highly specific ways.
Recordings of brain activity can be made using electrodes, either glued to the scalp as in EEG studies, or implanted inside the brains of animals for extracellular recordings, which can detect action potentials generated by individual neurons. The same techniques have occasionally been used to study brain activity in human patients suffering from intractable epilepsy , in cases where there was a medical necessity to implant electrodes to localize the brain area responsible for epileptic seizures.
Another approach to brain function is to examine the consequences of damage to specific brain areas. Even though it is protected by the skull and meninges , surrounded by cerebrospinal fluid , and isolated from the bloodstream by the blood—brain barrier, the delicate nature of the brain makes it vulnerable to numerous diseases and several types of damage. In humans, the effects of strokes and other types of brain damage have been a key source of information about brain function.
Because there is no ability to experimentally control the nature of the damage, however, this information is often difficult to interpret. In animal studies, most commonly involving rats, it is possible to use electrodes or locally injected chemicals to produce precise patterns of damage and then examine the consequences for behavior. Computational neuroscience encompasses two approaches: On one hand, it is possible to write a computer program to simulate the operation of a group of neurons by making use of systems of equations that describe their electrochemical activity; such simulations are known as biologically realistic neural networks.
On the other hand, it is possible to study algorithms for neural computation by simulating, or mathematically analyzing, the operations of simplified "units" that have some of the properties of neurons but abstract out much of their biological complexity. The computational functions of the brain are studied both by computer scientists and neuroscientists. Computational neurogenetic modeling is concerned with the study and development of dynamic neuronal models for modeling brain functions with respect to genes and dynamic interactions between genes.
Recent years have seen increasing applications of genetic and genomic techniques to the study of the brain  and a focus on the roles of neurotrophic factors and physical activity in neuroplasticity. It is now possible with relative ease to "knock out" or mutate a wide variety of genes, and then examine the effects on brain function.
More sophisticated approaches are also being used: The oldest brain to have been discovered was in Armenia in the Areni-1 cave complex. The brain, estimated to be over 5, years old, was found in the skull of a 12 to year-old girl. Although the brains were shriveled, they were well preserved due to the climate found inside the cave.
Early philosophers were divided as to whether the seat of the soul lies in the brain or heart. Aristotle favored the heart, and thought that the function of the brain was merely to cool the blood.
Democritus, the inventor of the atomic theory of matter, argued for a three-part soul, with intellect in the head, emotion in the heart, and lust near the liver. In his treatise on epilepsy he wrote:. Men ought to know that from nothing else but the brain come joys, delights, laughter and sports, and sorrows, griefs, despondency, and lamentations.
And by the same organ we become mad and delirious, and fears and terrors assail us, some by night, and some by day, and dreams and untimely wanderings, and cares that are not suitable, and ignorance of present circumstances, desuetude, and unskillfulness.
All these things we endure from the brain, when it is not healthy The Roman physician Galen also argued for the importance of the brain, and theorized in some depth about how it might work.
Galen traced out the anatomical relationships among brain, nerves, and muscles, demonstrating that all muscles in the body are connected to the brain through a branching network of nerves. He postulated that nerves activate muscles mechanically by carrying a mysterious substance he called pneumata psychikon , usually translated as "animal spirits".