Karen Ravn The authors of a new study write that this plant bug, Coridromius tahitiensis, “lacks precopulatory courtship, and males instead pounce on nearby females, with whom they struggle violently in their attempt to mate.” If you lived on an exotic island where unsafe sex was all too common, you'd find ways to ward off unwanted attention. On Tahiti, the females of two related insect species have had to move their genitals to different sides of their bodies and even impersonate the opposite sex — all to avoid getting pierced in the abdomen by the sexual organs of the wrong males, biologists report. The two insects, which live side by side on the Pacific island of Tahiti and feed on the same plants, are known as Coridromius tahitiensis and Coridromius taravao. Both species follow the aptly named practice of traumatic insemination. With his genital organ reminiscent of a hypodermic needle, the male stabs a female in the side and shoots sperm into her abdomen. The ritual — shared by a number of other invertebrates, including bedbugs (Cimex lectularius) — can cause injury or infection for the female. Not only that, but insects that use this type of reproductive method are not particularly persnickety about partners, so a male of one species may try to mate with another male — or even with a member of another species. Such interspecies mating can be costly to both species in terms of wasted time, energy and sperm, says Nikolai Tatarnic, a biologist who is now curator of insects at the Western Australian Museum in Welshpool. © 2013 Nature Publishing Group,

Keyword: Sexual Behavior; Evolution
Link ID: 18535 - Posted: 08.20.2013

by Douglas Main, LiveScience Staff Writer Rock-a-bye owlet, in the treetop … Baby owls and baby mammals, including humans, sleep in an analogous manner, spending a similar amount of time in an awakelike phase called REM (rapid-eye movement), in which dreams are thought to occur, at least during adulthood, new research suggests. In both owls and humans, REM sleep decreases with increasing age. Baby humans spend about 50 percent of their snooze time in this REM phase, whereas that figure decreases to less than 25 percent in adults, according to a statement from the Max Planck Institute for Ornithology. (Applying the REM term to owls, whose eyes are fixed in their heads, may seem a stretch, but researchers use the phrase anyway.) In the new study, published in July in the journal Frontiers in Zoology, the researchers attached electroencephalograms (EEGs) and movement data loggers to 66 young barn owls to record how much time the animals spent in REM sleep and how much they moved while snoozing. They later removed the EEGs, which measure brain waves, and found that the birds mated normally and didn't appear to have suffered any negative effects from the devices, the statement noted. (7 Ways Animals Act Like Humans) "During this sleep phase, the owlets' EEG showed awakelike activity, their eyes remained closed, and their heads nodded slowly," said University of Lausanne researcher Madeleine Scriba in the statement. © 2013 Discovery Communications, LLC.

Keyword: Sleep; Development of the Brain
Link ID: 18534 - Posted: 08.20.2013

By Scicurious It’s something we feel we’ve always known: if you can’t sleep, you need to exercise more. Wear yourself out, make yourself good and tired, you’ll sleep like a baby! So when I started having trouble sleeping, I just figured I needed to work out more. Of course, it kind of figures that often, you have trouble sleeping because of life stress, which often means you’re really busy, which in turn means it probably puts MORE stress in your life just trying to find the time to work out. But that’s just details. So sometimes, when I catch myself constantly waking up in a panic over several days, I’ll fit in some hard exercise. Maybe I’ll go for a long run, or try a really hard new class or something. By the time I go to bed I am WIPED. Physically and mentally. My body is so exhausted that the feeling of lying down is one of total bliss. …so why can’t I SLEEP?!?! Turns out I was suffering under expectations that were a little too high for reality. First off, we’re not wrong. Exercise DOES improve sleep. It does. But not necessarily immediately. And perhaps, instead, we should ask a different question. Instead of asking how exercise impacts sleep, perhaps we should ask how sleep impacts exercise. The authors of this study were looking at exercise and sleep, especially in the elderly. We all sleep less as we get older, but chronic insomnia is a different beast entirely. When we don’t get enough sleep, we get snappish, have trouble concentrating, suffer from daytime sleepiness, and are more susceptible to things like getting sick, or getting in to accidents. © 2013 Scientific American

Keyword: Sleep
Link ID: 18533 - Posted: 08.20.2013

By James Gallagher Health and science reporter, BBC News A lifetime of too much copper in our diets may be contributing to Alzheimer's disease, US scientists say. However, research is divided, with other studies suggesting copper may actually protect the brain. The latest study in Proceedings of the National Academy of Sciences showed high levels of copper left the brain struggling to get rid of a protein thought to cause the dementia. Copper is a vital part of our diet and necessary for a healthy body. Tap water coming through copper pipes, red meat and shellfish as well as fruit and vegetables are all sources of dietary copper. Barrier The study on mice, by a team at the University of Rochester in New York, suggested that copper interfered with the brain's shielding - the blood brain barrier. Mice that were fed more copper in their water had a greater build-up of the metal in the blood vessels in the brain. The team said this interfered with the way the barrier functioned and made it harder for the brain to get rid of a protein call beta amyloid. One of the hallmarks of Alzheimer's disease is the formation of plaques of amyloid in the dying brain. Lead researcher Dr Rashid Deane said: "It is clear that, over time, copper's cumulative effect is to impair the systems by which amyloid beta is removed from the brain." BBC © 2013

Keyword: Alzheimers; Neurotoxins
Link ID: 18532 - Posted: 08.20.2013

By RICHARD A. FRIEDMAN, M.D. Fully 1 in 5 Americans take at least one psychiatric medication. Yet when it comes to mental health, we are facing a crisis in drug innovation. Sure, we have many antidepressants, antipsychotics, hypnotic medications and the like. But their popularity masks two serious problems. First, each of these drug classes is filled with “me too” drugs, which are essentially just copies of one another; we have six S.S.R.I. antidepressants that essentially do the same thing, and likewise for the 10 new atypical antipsychotic drugs. Second, the available drugs leave a lot to be desired: patients with illnesses like schizophrenia, major depression and bipolar disorder often fail to respond adequately to these medications or cannot tolerate their side effects. Yet even though 25 percent of Americans suffer from a diagnosable mental illness in any year, there are few signs of innovation from the major drug makers. After a series of failed clinical trials in which novel antidepressants and antipsychotics did little or no better than placebos, the companies seem to have concluded that developing new psychiatric drugs is too risky and too expensive. This trend was obvious at the 2011 meeting of the American Society for Clinical Pharmacology and Therapeutics, where only 13 of 300 abstracts related to psychopharmacology and none related to novel drugs. Instead, they are spending most of their research dollars on illnesses like cancer, heart disease and diabetes, which have well-defined biological markers and are easier to study than mental disorders. © 2013 The New York Times Company

Keyword: Depression; Schizophrenia
Link ID: 18531 - Posted: 08.20.2013

What if a psychiatrist could tell whether someone was about to commit suicide simply by taking a sample of their blood? That’s the promise of new research, which finds increased amounts of a particular protein in the bloodstream of those contemplating killing themselves. The test was conducted on only a few people, however, and given that such “biomarkers” often prove unreliable in the long run, it’s far from ready for clinical use. Suicide isn’t like a heart attack. People typically don’t reveal early symptoms to their doctor—morbid thoughts, for example, instead of chest pain—and there’s no equivalent of a cholesterol or high blood pressure test to identify those at most risk of killing themselves. "We are dealing with something more complex and less accessible," says Alexander Niculescu III, a psychiatrist at the Indiana University School of Medicine in Indianapolis. So some researchers are eager to find physical signs, called biomarkers, that can be measured in the bloodstream to signal when a person is at a high likelihood of committing suicide. Over the past decade, Niculescu and his colleagues have been refining a method for identifying biomarkers that can distinguish psychological states. The technique depends on blood samples taken from individuals in different mental states over time—for example, from people with bipolar disorder as they swing between the disorder’s characteristic high and low moods. The researchers test those samples for differences in the activity, or expression, of genes for of different proteins. After screening the blood samples, the scientists “score” a list of candidate biomarker genes by searching for related results in a large database of studies by other groups using a program that Niculescu compares to the Google page-ranking algorithm. In previous published studies, Niculescu and other groups have used the technique to probe for biomarkers in disorders such as bipolar disorder, psychosis, and alcoholism. © 2012 American Association for the Advancement of Science.

Keyword: Depression
Link ID: 18530 - Posted: 08.20.2013

By ANAHAD O'CONNOR Nationwide, roughly a third of all visits to emergency rooms for injuries are alcohol related. Now a new study suggests that certain beverages may be more likely to be involved than others. The study, carried out over the course of a year at the Johns Hopkins Hospital in Baltimore, found that five beer brands were consumed most often by people who ended up in the emergency room. They were Budweiser, Steel Reserve, Colt 45, Bud Ice and Bud Light. Three of the brands are malt liquors, which typically contain more alcohol than regular beer. Four malt liquors accounted for nearly half of the beer consumption by emergency room patients, even though they account for less than 3 percent of beer consumption in the general population. Previous studies have found that alcohol frequently plays a role in emergency room admissions, especially those stemming from car accidents, falls, homicides and drownings, said the lead author of the study, David H. Jernigan of the Johns Hopkins Bloomberg School of Public Health. The new study, published in the journal Substance Use and Misuse, is the first to look at whether certain brands or types of liquor are overrepresented. Dr. Jernigan said that the breakdown of liquor consumption in the study may be particular to Baltimore, and that he and his colleagues are hoping to study other cities as well. The findings could have policy implications, potentially influencing labeling requirements and marketing for higher-alcohol beers, Dr. Jernigan said. Copyright 2013 The New York Times Company

Keyword: Drug Abuse; Aggression
Link ID: 18529 - Posted: 08.20.2013

By Scott Barry Kaufman So yea, you know how the left brain is really realistic, analytical, practical, organized, and logical, and the right brain is so darn creative, passionate, sensual, tasteful, colorful, vivid, and poetic? No. Just no. Stop it. Please. Thoughtful cognitive neuroscientists such as Rex Jung, Darya Zabelina, Andreas Fink, John Kounios, Mark Beeman, Kalina Christoff, Oshin Vartanian, Jeremy Gray, Hikaru Takeuchi and others are on the forefront of investigating what actually happens in the brain during the creative process. And their findings are overturning conventional notions surrounding the neuroscience of creativity. The latest findings from the real neuroscience of creativity suggest that the right brain/left brain distinction is not the right one when it comes to understanding how creativity is implemented in the brain. Creativity does not involve a single brain region or single side of the brain. Instead, the entire creative process– from the initial burst of inspiration to the final polished product– consists of many interacting cognitive processes and emotions. Depending on the stage of the creative process, and what you’re actually attempting to create, different brain regions are recruited to handle the task. Importantly, many of these brain regions work as a team to get the job done, and many recruit structures from both the left and right side of the brain. In recent years, evidence has accumulated suggesting that “cognition results from the dynamic interactions of distributed brain areas operating in large-scale networks.” © 2013 Scientific American

Keyword: Laterality; Attention
Link ID: 18528 - Posted: 08.20.2013

By April Neale An innovative two-part series, "Brains on Trial with Alan Alda," airing Wednesday, September 11 and 18, 2013, 10-11 p.m. on PBS (check local listings), explores how the growing ability to separate truth from lies, even decode people’s thoughts and memories, may radically affect how criminal trials are conducted in the future. As brain scanning techniques advance, their influence in criminal cases is becoming critically important. Brains on Trial centers around the trial of a fictional crime: a robbery staged in a convenience store that has been filmed by the store’s security cameras. A teenager stands accused of the attempted murder of the store clerk’s wife who was shot during the crime. While the crime is fictional, the trial is conducted before a real federal judge and argued by real practicing attorneys. The program is divided into two-parts: the first hour examines the guilt phase of the trial concluding with the jury’s verdict; the second hour looks at the sentencing phase, when arguments for and against a severe sentence are heard. As the trial unfolds, Alda visits with neuroscientists whose research has already influenced some Supreme Court decisions, as well as Duke University law professor Nita Farahany, a member of the Presidential Commission for the Study of Bioethical Issues. On these visits, neuroscientists show how functional MRIs and other brain scanning techniques are exploring lie detection, facial recognition, memory decoding, racial bias, brain maturity, intention, and even emotions. The research Alda discovers is at the center of a controversy as to how this rapidly expanding ability to peer into people’s minds and decode their thoughts and feelings could – or should – affect trials like the one presented in the program. As DNA evidence has played a major role in exonerating innocent prisoners, Brains on Trial asks if neuroscience can make the criminal justice system more just.

Keyword: Miscellaneous
Link ID: 18527 - Posted: 08.20.2013

By Brady Dennis, Insomniacs of the world: If you think taking a long run today will make you sleep better tonight, think again. While exercise has long been a prescription for insomnia, new research suggests that exercise doesn’t immediately translate into a better night’s sleep — unless you stick with it for months. A study published Thursday in the Journal of Clinical Sleep Medicine found that aerobic exercise can lead to more rest at night for people who suffer from existing sleep problems, but only if they maintain an exercise regimen for roughly four months. “Exercise isn’t a quick fix. . . . It takes some time and effort,” the study’s lead author, Kelly Glazer Baron, a clinical psychologist and director of the behavioral sleep program at Northwestern University’s Feinberg School of Medicine, said in an interview. “It’s a long-term relationship.” Studies have long suggested that aerobic exercise can contribute to better sleeping habits. But much of the research on the daily effects of exercise on sleep was conducted with healthy sleepers. Tuesday’s study, by contrast, looked at the long-term effects of exercise in people already suffering from sleep disorders. © 1996-2013 The Washington Post

Keyword: Sleep
Link ID: 18526 - Posted: 08.19.2013

The EnChroma Color Blindness Test measures the type and extent of color vision deficiency. The test takes between 2-5 minutes to complete. Your test results may be anonymously recorded on our server for quality assurance purposes. This test is not a medical diagnosis. Please consult an eye care professional for more information regarding color vision deficiency. Copyright 2013 EnChroma, Inc.

Keyword: Vision
Link ID: 18525 - Posted: 08.19.2013

A few weeks back, I wrote about special lenses that were developed to give doctors “a clearer view of veins and vasculature, bruising, cyanosis, pallor, rashes, erythema, and other variations in blood O2 level, and concentration,” especially in bright light. But these lenses turned out to have an unintended side effect: they “may cure red-green colorblindness.” I’m severely red-green colorblind, so I was eager to try these $300 lenses. Turns out they didn’t help me; the company said that my colorblindness is too severe. They have helped many others, though (their Amazon reviews makes that clear). After my column appeared, I heard from another company that makes color-enhancing glasses — this time, specifically for red-green colorblind folks. The company’s called EnChroma, and the EnChroma Cx sunglasses are a heartbeat-skipping $600 a pair. “Our lenses are specifically designed to address color blindness,” the company wrote to me, “and utilize a 100+ layer dielectric coating we engineered for this precise purpose by keeping the physiology of the eyes of colorblind people in mind.” I asked to try out a pair. (You can, too: there’s a 30-day money-back guarantee.) To begin, you figure out which kind of colorblindness you have — Protan or Deutan — by taking the test at enchroma.com. Turns out I have something called Strong Protan. (“Protanomaly is a type of red-green color vision deficiency related to a genetic anomaly of the L-cone (i.e. the red cone).”) I’d never heard of it, but whatever. © 2013 The New York Times Company

Keyword: Vision
Link ID: 18524 - Posted: 08.19.2013

By SABRINA TAVERNISE BALTIMORE — At Everest Greenish Grocery, a brightly lit store on a faded corner of this city, nothing is more popular than a chocolate-flavored little cigar. They are displayed just above the Hershey bars along with their colorful cigarillo cousins — white grape, strawberry, pineapple and Da Bomb Blueberry. And they were completely sold out by 9 one recent evening, snapped up by young people dropping by for a snack or stopping in during a night of bar hopping. “Sorry, no more chocolate,” the night clerk, Qudrad Bari, apologetically told a young woman holding a fruit drink. In 2009, Congress passed a landmark law intended to eliminate an important gateway to smoking for young people by banning virtually all the flavors in cigarettes that advocates said tempted them. Health experts predicted that the change would lead to deep reductions in youth smoking. But the law was silent on flavors in cigars and a number of other tobacco products, instead giving the Food and Drug Administration broad discretion to decide whether to regulate them. Four years later, the agency has yet to assert that authority. And a rainbow of cheap flavored cigars and cigarillos, including some that look like cigarettes, line the shelves of convenience stores and gas stations, often right next to the candy. F.D.A. officials say they intend to regulate cigars and other tobacco products, but they do not say how or when. Smoking opponents contend that the agency’s delay is threatening recent progress in reducing smoking among young people. © 2013 The New York Times Company

Keyword: Drug Abuse
Link ID: 18523 - Posted: 08.19.2013

By Cristy Gelling Repairing a faulty communication line between the gut and the brain can quell the urge to overeat, an experiment that cured chubby mice of their junk food addiction indicates. A similar strategy might be used to treat compulsive eating in people. Some scientists have proposed that, in both mice and humans, overeating can resemble drug addiction; the more food a person consumes, the less responsive the brain becomes to the pleasure of eating. By restoring normal communication between the gut and brain, researchers were able to resensitize overfed rodents to the pleasures of both fatty and healthy foods. "The therapeutic implications are huge,” says neuroscientist Paul Kenny of the Scripps Research Institute in Jupiter, Fla., who was not involved in the study. In the brain, a chemical called dopamine surges in response to pleasurable experiences like eating, sex and taking drugs. But brain-scanning studies suggest that obese individuals have muted dopamine reponses to food. These changes could lead overeaters to seek more and more food to satisfy their cravings, suggests study leader Ivan de Araujo of Yale University. De Araujo and his colleagues looked for ways to restore the dopamine response of overfed mice by studying the signals sent by their guts. In previous work, the researchers found that mice get a dopamine rush when fat is introduced directly into the small intestine via catheters. This shows that the gut communicates with the brain’s reward center even when the mouse can’t taste food. © Society for Science & the Public 2000 - 2013

Keyword: Obesity; Drug Abuse
Link ID: 18522 - Posted: 08.17.2013

Drinking several servings of soda a day is associated with behaviour problems such as aggression, a new study of preschoolers suggests. When researchers looked at 2,929 children in the U.S., they found 43 per cent of parents said their child had at least one serving of soda a day and four per cent had four or more servings daily. Four per cent of parents in the study reported their children had four or more servings of pop a day. Sugar and caffeine are potential triggers for behaviour, but parenting practices and home environment are also an influence.Four per cent of parents in the study reported their children had four or more servings of pop a day. Sugar and caffeine are potential triggers for behaviour, but parenting practices and home environment are also an influence. (Reuters) "In this large sample of five-year-old urban U.S. children, we found strong and consistent relationships between soda consumption and a range of problem behaviours, consistent with the findings of previous studies in adolescents," Shakira Suglia of Columbia University's Mailman School of Public Health in New York and her coauthors concluded in Friday's issue of the Journal of Pediatrics. Children who consumed four or more servings of soda per day were more than twice as likely to destroy things belonging to others, to get into fights and to physically attack people compared with children who drank no soda. Drinking four servings of soft drinks was associated with increased aggressive behaviour, even after accounting for factors such as TV viewing, candy consumption, maternal depression and intimate partner violence. © CBC 2013

Keyword: Aggression; Obesity
Link ID: 18521 - Posted: 08.17.2013

By Susana Martinez-Conde Want to know an effective way to reduce pain from burns? Cover the affected red area, so you are unable to look at it. Ideally, use a blue bandage. Painfully hot stimuli applied to red skin feel more painful than applied to blue skin, a new research article published in Frontiers in Human Neuroscience shows. The scientists, Matteo Martini, Daniel Perez-Marcos and Maria Victoria Sanchez-Vives from the University of Barcelona, used immersive virtual reality in combination with the application of real heat stimuli to the wrists of experimental subjects. Participants saw their virtual arms get increasingly red, blue, or green as the heat rose, and indicated, by pressing a button, when the sensation became painful. In an additional experimental condition, a gray dot close to the virtual arm became red as the temperature increased, but the color of the arm itself remained unaltered. The results showed that subjects experienced pain earlier (that is, at lower physical temperatures) when the arm was red than when it was blue. Also, the experience of increased pain was not associated to seeing red per se, but it mattered whether the color was on the body or not. A patch of red near –but not on– the virtual arm resulted in significantly less pain than that recorded with the arm itself becoming red. © 2013 Scientific American

Keyword: Pain & Touch; Emotions
Link ID: 18520 - Posted: 08.17.2013

by Linda Geddes "IT WAS like red-hot pokers needling one side of my face," says Catherine, recalling the cluster headaches she experienced for six years. "I just wanted it to stop." But it wouldn't – none of the drugs she tried had any effect. Thinking she had nothing to lose, last year she enrolled in a pilot study to test a handheld device that applies a bolt of electricity to the neck, stimulating the vagus nerve – the superhighway that connects the brain to many of the body's organs, including the heart. The results of the trial were presented last month at the International Headache Congress in Boston, and while the trial is small, the findings are positive. Of the 21 volunteers, 18 reported a reduction in the severity and frequency of their headaches, rating them, on average, 50 per cent less painful after using the device daily and whenever they felt a headache coming on. This isn't the first time vagal nerve stimulation has been used as a treatment – but it is one of the first that hasn't required surgery. Some people with epilepsy have had a small generator that sends regular electrical signals to the vagus nerve implanted into their chest. Implanted devices have also been approved to treat depression. What's more, there is increasing evidence that such stimulation could treat many more disorders from headaches to stroke and possibly Alzheimer's disease (see "The many uses of the wonder nerve"). © Copyright Reed Business Information Ltd.

Keyword: Pain & Touch
Link ID: 18519 - Posted: 08.17.2013

by Laura Poppick, LiveScience Researchers have widely examined homosexual behavior in mammals and birds, but have addressed it less frequently in insects and spiders. To assess the range of evolutionary explanations for same-sex intercourse in the invertebrate world, a team of biologists from Tel Aviv University in Israel and the Swiss Federal Institute of Technology in Zurich, Switzerland examined roughly 100 existing studies on the topic and compiled the first comprehensive review of homosexuality in invertebrates. The review was published earlier this month in the journal Behavioral Ecology and Sociobiology. The team focused on male-male interactions to simplify the analysis, and found that most of these encounters occurred as accidents. Whereas larger animals have developed more complicated homosexual motivations — like maintaining alliances, which has been found in certain primate and seagull species — insects seem to mistakenly partake in it in a hasty attempt to secure mates. [Gay Animals: Alternate Lifestyles in the Wild] "They have evolved to mate quick and dirty," said study co-author Inon Scharf, an evolutionary ecologist at Tel Aviv University. "They grab every opportunity to mate that they have because, if they become slow, they may give up an opportunity to mate." In some cases, males carry around the scent of females they have just mated with, sending confusing signals to other perusing males. In other cases, males and females look so similar to one another that males cannot tell if a potential mate is a female until he mounts "her" and prepares for the act, Scharf said. © 2013 Discovery Communications, LLC.

Keyword: Sexual Behavior; Evolution
Link ID: 18518 - Posted: 08.17.2013

by Sara Reardon It can be nearly impossible to know what is happening in the mind of someone who has experienced a severe brain injury, but two new methods could offer some clues. Together, they provide not only a better indication of consciousness but also a more effective way to communicate with some vegetative people. The way that a seemingly unconscious person behaves does not always reflect their mental state. Someone in a completely vegetative state may still be able to smile simply through reflex, while a perfectly alert person may be left unable to do so if a brain injury has affected their ability to move. So a different way to assess mental state is needed. Marcello Massimini at the University of Milan in Italy and his colleagues have developed a possible solution by stimulating brains with an electromagnetic pulse and then measuring the response. The pulse acts like striking a bell, they say, and neurons across the entire brain continue to "ring" in a specific wave pattern, depending on how active the connections between individual brain cells are. The team used this method to assess 20 people with brain injuries who were either in a vegetative state, in a minimally conscious state, or in the process of emerging from a coma. The team compared the patterns from these people with the patterns recorded from 32 healthy people who were awake, asleep or under anaesthesia. In each of the distinct states of consciousness, the researchers found, the neurons "shook" in a distinctive pattern in response to the electromagnetic pulse. © Copyright Reed Business Information Ltd

Keyword: Consciousness
Link ID: 18517 - Posted: 08.17.2013

NICHOLAS SPITZER is a professor of neuroscience at the University of California. His research concentrates on the ways in which neurons take on specialised functions to enable signalling in the brain. He is editor-in-chief of BrainFacts.org, a public information service about the brain and nervous system, and is instrumental in the BRAIN Initiative, a research project backed by the White House to advance new technologies to help map the brain. What do you know about the brain that the rest of us don’t? The structure and function of the brain are determined by genes and environment. We think we know this—it’s nature and nurture—but what many don’t realise is that this remains true throughout life. People think the brain is malleable only when we’re young. But that’s just not true. The forms of plasticity we see in the young brain are sustained in the mature brain. By plasticity I mean the ability of the brain to change its structure and function in response to changes in the environment. In addition to the classical ways the brain changes (the strength of the connections, synapses and neurons) we now understand a third kind of brain plasticity in which the neurotransmitter molecules—the signals from one neuron to another—can actually switch. What does this mean for human development? Our experiments have mainly been done on adult rats. A finding that is directly related to the human condition is that putting the animals on different photoperiods [day and night cycles] changes the neurotransmitter identity in the hypothalamus [a part of the brain] and this changes the animal’s behaviour. When animals are on a short day (rats are nocturnal so a short day is good) they make dopamine, the reward chemical. On the long day the neurons switch from dopamine to somatostatin, which retards growth. © The Economist Newspaper Limited 2013.

Keyword: Biological Rhythms
Link ID: 18516 - Posted: 08.17.2013