A hormone patch may protect women with schizophrenia or other severe mental illnesses from psychotic feelings. Australian scientists found that women given the sex hormone oestrogen were less likely to report suffering hallucinations or delusions. Writing in the Archives of General Psychiatry Journal, they said the hormone might be enhancing blood flow to the brain. A UK mental health charity said funding was now needed for bigger studies. While men do have some oestrogen in their bodies, it is produced in much greater concentrations in the female body, where, among other functions, it helps regulate the menstrual cycle. The link between oestrogen and mental illness was first recognised more than a century ago, but only recently has it been considered as a possible treatment. The researchers from Monash University in Melbourne recruited more than 100 women with diagnosed schizophrenia, half of whom were given a patch containing estradiol - the most common form of oestrogen. The other half also wore a patch, but with no active drugs, and both groups carried on taking their normal medication. Over the next month, their symptoms and feelings were recorded on a weekly basis. The group given estradiol had a greater improvement in psychotic symptoms over that period, and were less likely to report other negative changes in their condition. (C)BBC

Keyword: Schizophrenia; Hormones & Behavior
Link ID: 11902 - Posted: 08.05.2008

By John Pearson and Michael Platt The insight that neurological functions could be localized in the brain—that activities such as speech, vision and hearing take place in fixed locations, with the aid of specialized neural circuits—has served as one of the driving ideas in neuroscience. Less often appreciated is the companion notion that the power of the brain, the key to its flexibility and coordination, lies not just in the capacities of these dedicated processing centers, but also in the connections among them. It is not enough, as the phrenologists proposed centuries ago, to have islands of specialized function for each of the brain’s activities. For modern neuroscientists, the whole story must lie not just in the brain’s compartmentalization, but in its communication. Nevertheless, modern neuroscience techniques often focus on localization at the expense of communication. Whole-brain imaging techniques such as functional MRI, for example, have allowed researchers to gain some insight into which regions of the brain are more active during a given behavior. But the most direct technique available for studying brain function during behavior—measuring the electrical activity of individual neurons—typically focuses on a specific location within the brain. This is not only because the technical challenges posed by simultaneous recordings in several brain areas are daunting, but also because many regions remain poorly understood, and others frequently share so many connections with the rest of the brain that they often appear to be involved in everything. Most of the time, the neural circuits involved are sufficiently complex that neuroscientists are simply trying to get a handle on what role, if any, a particular brain area plays in behavior; try to factor in communication among several of them, and most hypotheses become too complicated to test directly. In effect, studying information flow within the brain becomes a bit like tapping into a massive network switchbox: there’s a constant stream of information flowing past, but without a clever experiment, it’s nearly impossible to tell just where that information is going or how it’s being used. Unfortunately, these are the very questions neuroscientists suspect are most crucial for understanding one of the most complex of human behaviors: how we make decisions. © 1996-2008 Scientific American Inc

Keyword: Brain imaging
Link ID: 11901 - Posted: 06.24.2010

By BENEDICT CAREY Even the most fabulous, high-flying lives hit pockets of dead air, periods when the sails go slack. Movie stars get marooned in D.M.V. lines. Prime ministers sit with frozen smiles through interminable state events. Living-large rappers endure empty August afternoons, pacing the mansion, checking the refrigerator, staring idly out the window, baseball droning on the radio. Scientists know plenty about boredom, too, though more as a result of poring through thickets of meaningless data than from studying the mental state itself. Much of the research on the topic has focused on the bad company it tends to keep, from depression and overeating to smoking and drug use. Yet boredom is more than a mere flagging of interest or a precursor to mischief. Some experts say that people tune things out for good reasons, and that over time boredom becomes a tool for sorting information — an increasingly sensitive spam filter. In various fields including neuroscience and education, research suggests that falling into a numbed trance allows the brain to recast the outside world in ways that can be productive and creative at least as often as they are disruptive. In a recent paper in The Cambridge Journal of Education, Teresa Belton and Esther Priyadharshini of East Anglia University in England reviewed decades of research and theory on boredom, and concluded that it’s time that boredom “be recognized as a legitimate human emotion that can be central to learning and creativity.” Copyright 2008 The New York Times Company

Keyword: Attention
Link ID: 11900 - Posted: 06.24.2010

By NATALIE ANGIER Here is a fun and easy experiment that Rachel Herz of Brown University suggests you try at home, but only if you promise to eat your vegetables first, floss afterward, and are not at risk of a diabetic coma. Buy a bag of assorted jelly beans of sufficiently high quality to qualify, however oxymoronically, as “gourmet.” Then, sample all the flavors in the bag systematically until you are sure you appreciate just how distinctive each one is, because expertise is important and you may never get another excuse this good. Now for the meat of our matter: pinch your nostrils shut and do the sampling routine again. Notice the differences? That’s right — now there are none. Every bean still tastes sweet, but absent a sense of smell you might as well be eating sugared pencil erasers. And if in midchew you unbind your nose, what then? At once the candy’s candid charms return, and you can tell your orange sherbet from a buttered popcorn. We’ve all heard about the mysterious powers of smell and its importance in love, friendship and food. Yet a simple game like What’s My Bean, and our consistent surprise at the impact of shutting down our smell circuits, shows that we don’t really grasp just how deep the nose goes. At the International Symposium on Olfaction and Taste held in San Francisco late last month, Dr. Herz and other researchers discussed the many ways our sense of smell stands alone. Olfaction is an ancient sense, the key by which our earliest forebears learned to approach or slink off. Yet the right aroma can evoke such vivid, whole body sensations that we feel life’s permanent newness, the grounding of now. Copyright 2008 The New York Times Company

Keyword: Chemical Senses (Smell & Taste); Emotions
Link ID: 11899 - Posted: 06.24.2010

By Greg Miller Early Saturday morning, a Molotov-cocktail-like device set fire to the home of a developmental neurobiologist at the University of California, Santa Cruz (UCSC). His family escaped by climbing down a fire escape from a second-story window. Around the same time, a similar device destroyed the car of another UCSC researcher. As ScienceNOW went to press, no one had claimed responsibility for the attacks, but the university and police suspect they are the work of animal-rights extremists. In recent years, universities and law enforcement officials in the United States have had to grapple with increasingly personal threats, harassment, and attacks on animal researchers and their families (Science, 21 December 2007, p. 1856). California has been an epicenter of such animal-rights extremism: Several biomedical researchers at UC Los Angeles have been targeted in recent years, and more recently, scientists at other University of California (UC) campuses have endured harassment and had their homes vandalized. Twenty-four UC Berkeley researchers and seven staff members have been harassed in recent months, according to a university spokesperson. In February, six masked intruders tried to force their way into the home of a UCSC researcher during a birthday party for her young daughter. Concerns were sparked again last week in Santa Cruz by pamphlets discovered in a downtown coffee shop and turned in to police. Titled "Murderers and Torturers Alive and Well in Santa Cruz," they contained the photographs, home addresses, and phone numbers of 13 UCSC faculty members, along with "threat-laden language" condemning animal research, says Captain Steve Clark of the Santa Cruz police. © 2008 American Association for the Advancement of Science.

Keyword: Animal Rights
Link ID: 11898 - Posted: 06.24.2010

Daniel Cressey Whales subjected to military sonar will neither dive nor feed, according to an unpublished 2007 report from the UK military, obtained by Nature after a request under the Freedom of Information Act 2000. The impact of sonar on whales has become an increasingly fraught issue in recent years, with submarine exercises being linked to several high-profile mass strandings. The US Navy has admitted concerns over sonar’s effects on marine mammals, although actual evidence for harm has been in short supply. submarineSubmarines' sonar has been implicated in whale strandings.Punchstock But military-sponsored tests now suggest that low levels of sonar, which do not cause direct damage to whales, could still cause harm by triggering behavioural changes. The UK military report details observations of whale activity during Operation Anglo-Saxon 06, a submarine war-games exercise in 2006. Produced for the UK’s Defence Science and Technology Laboratory, it states the results are “potentially very significant”. The study used an array of hydrophones to listen for whale sounds during the war games. Across the course of the exercise, the number of whale recordings dropped from over 200 to less than 50. “Beaked whale species ... appear to cease vocalising and foraging for food in the area around active sonar transmissions,” concludes the report. © 2008 Nature Publishing Group

Keyword: Hearing; Animal Migration
Link ID: 11897 - Posted: 06.24.2010

By Drake Bennett In September of 1856, in the face of a growing rebellion, Napoleon III dispatched Jean-Eugene Robert-Houdin to Algeria. Robert-Houdin was not a general, nor a diplomat. He was a magician - the father, by most accounts, of modern magic. (A promising young escape artist named Ehrich Weiss would, a few decades later, choose his stage name by adding an "i" to "Houdin.") His mission was to counter the Algerian marabouts, conjurers whose artful wizardry had helped convince the Algerian populace of Allah's displeasure with French rule. A French colonial official assembled an audience of Arab chieftains, and Robert-Houdin put on a show that, in its broadest outlines, would be familiar to today's audiences: he pulled cannonballs out of his hat, he plucked lit candelabra out of the air, he poured gallon upon gallon of coffee out of an empty silver bowl. Then, as he recounted in his memoirs, Robert-Houdin launched into a piece of enchantment calculated to cow the chieftains. He had a small wooden chest with a metal handle brought onto the stage. He picked a well-muscled member of the audience and asked him to lift the box; the man did it easily. Then Robert-Houdin announced, with a menacing wave of his hand, that he had sapped the man's strength. When the volunteer again took hold of the box, it would not budge - an assistant to Robert-Houdin had activated a powerful magnet in the floor of the stage. The volunteer heaved at the box, his frustration shading into desperation until Robert-Houdin's assistant, at a second signal, sent an electric shock through the handle, driving the man screaming from the stage. The chieftains were duly impressed, and the rebellion quelled. © 2008 NY Times Co.

Keyword: Vision; Attention
Link ID: 11896 - Posted: 06.24.2010

By THE ASSOCIATED PRESS NEW YORK (AP)-- Biogen Idec Inc. (NASDAQ:BIIB) and Elan Corp. defended their multiple sclerosis drug Tysabri on Friday after reporting two new cases of a potentially fatal side effect, saying the treatment is still worth the risk to patients. There are no plans to pull the drug off the market, and the company said its current monitoring program for cases of a rare but sometimes fatal brain disorder is adequate. The announcement of two new cases of the rare viral infection called progressive multifocal leukoencephalopathy, or PML, sent shares for both companies plummeting and reignited already simmering concerns about the drug's sales potential. It was pulled from the market in 2005 after being linked to the rare brain disease but was reintroduced under restricted sales conditions in mid-2006. "These cases underscore the importance of continued clinical vigilance so PML can be discovered and managed appropriately," said Dr. Cecil B. Pickett, president of research and development at Biogen. He and several other executives tried to allay concerns over additional cases during a conference call with financial investors and analysts Friday morning. The company said it would also hold calls with several physician and patient groups. The risks associated with the drug are clearly labeled, the company said, and all patients are not only notified but have to sign a waiver acknowledging the risks. PML almost always occurs in people with a severe immune deficiency, as is the case with most patients taking Tysabri. Copyright 2008 The Associated Press

Keyword: Multiple Sclerosis; Neuroimmunology
Link ID: 11895 - Posted: 08.02.2008

Helen Philips The Human Brain - With one hundred billion nerve cells, the complexity is mind-boggling. Learn more in our cutting edge special report. The brain is the most complex organ in the human body. It produces our every thought, action, memory, feeling and experience of the world. This jelly-like mass of tissue, weighing in at around 1.4 kilograms, contains a staggering one hundred billion nerve cells, or neurons. The complexity of the connectivity between these cells is mind-boggling. Each neuron can make contact with thousands or even tens of thousands of others, via tiny structures called synapses. Our brains form a million new connections for every second of our lives. The pattern and strength of the connections is constantly changing and no two brains are alike. It is in these changing connections that memories are stored, habits learned and personalities shaped, by reinforcing certain patterns of brain activity, and losing others. While people often speak of their "grey matter", the brain also contains white matter. The grey matter is the cell bodies of the neurons, while the white matter is the branching network of thread-like tendrils - called dendrites and axons - that spread out from the cell bodies to connect to other neurons. © Copyright Reed Business Information Ltd.

Keyword: Miscellaneous
Link ID: 11894 - Posted: 06.24.2010

Tamsin Osborne Remember when your mum told you that playing outside was good for you? She may have had a point, at least as far as your eyesight is concerned. Researchers in Australia have found an association between high levels of outdoor activity and low rates of short-sightedness, or myopia, in children. The prevalence of childhood myopia has increased dramatically in recent decades. With rates of 80% in some East Asian populations, the search is on for possible causes. "We know that there are genetic associations with myopia," says Kathryn Rose of the University of Sydney in Australia. "But the rapid changes in myopia prevalence are not consistent with a simple genetic determination, since gene pools do not change sufficiently fast." Suspecting that environmental factors might also be involved, Rose and colleagues set about investigating the effect that time spent outdoors has on the prevalence of myopia. In the study, 2367 12-year-old Australian schoolchildren underwent eye examinations and completed questionnaires about their daily activities. The lowest rates of myopia were associated with the highest rates of outdoor activity, irrespective of how much near work, such as reading, the children did. © Copyright Reed Business Information Ltd

Keyword: Vision
Link ID: 11893 - Posted: 06.24.2010

By Nathan Seppa The constant stress of "fight-or-flight" mode out of deep sleep may exacerbate other health problems over time. A common breathing disorder that disrupts sleep also, over time, increases the risk of death, a study in the August Sleep suggests. But people who use a nighttime breathing apparatus face less risk, the research shows. Obstructive sleep apnea is a disorder marked by gaps in breathing during sleep that rob the blood of oxygen until a person gasps for air. People with apnea stop breathing many times in an hour, which can jar them out of restful sleep and wreak havoc with blood pressure, heart rate and internal stress responses. In the United States, about one in six people may have sleep apnea, with one-fourth of those cases severe, Terry Young, an epidemiologist at the University of Wisconsin–Madison, estimates. Sleep apnea has received widespread attention as a health problem in the past 15 years, but data generated by Young’s team suggest 85 percent of sleep apnea cases still go undetected. While studies have suggested it carries risks, no study had, until now, tracked a population of healthy, middle-aged individuals for more than a decade to measure apnea’s effects. © Society for Science & the Public 2000 - 2008

Keyword: Sleep
Link ID: 11892 - Posted: 06.24.2010

By Tina Hesman Saey Dumb flies (and perhaps people) may need a little more shuteye, or a shot of dopamine, to boost their brain power. Fruit flies need sleep in order to learn, a study in the August 5 Current Biology shows. Keeping Drosophila up for hours after their normal bedtime impaired the flies’ ability to learn a complex task. But activating a particular receptor for the neurotransmitter dopamine in a brain structure called the mushroom bodies erased the learning deficits, researchers from Washington University in St. Louis found. The new study raises the possibility that learning is impaired not because sleep sneaks up on us when we’re supposed to be paying attention, but because staying awake too long erodes some biological process in the brain critical for learning and forming memories, says David Dinges, an experimental psychologist at the University of Pennsylvania School of Medicine in Philadelphia. Such hard evidence for a direct link between sleep and learning has eluded researchers who study sleep in people and other animals, says Marcos Frank, a sleep researcher at the University of Pennsylvania School of Medicine. That’s not for lack of trying. Scientists have amassed reams of data demonstrating behavioral evidence for the connection, but humans and other mammals are complex, making molecular studies difficult. © Society for Science & the Public 2000 - 2008

Keyword: Sleep; Learning & Memory
Link ID: 11891 - Posted: 06.24.2010

Chronic exposure to estrogen can impair memory, U.S. researchers report. The brain area affected is the prefrontal cortex, which controls working memory and allows a person to remember information pertaining to a certain task. Also affected are the ability to plan, respond to changing conditions and moderate or control one's behaviour. The pre-frontal cortex has estrogen receptors, meaning it binds to estrogen. Researchers conducted tests on rats, administering them to animals that had been given estrogen and to those who hadn't. Those who were exposed to estrogen performed poorly compared to those who hadn't been exposed, in both memory and waiting tests that involved pressing levers and responding to a stimulus. "That's the test where we really saw the most striking effects with estradiol," said Susan Schantz, lead author of the study. The estradiol-treated rats "were not as good at waiting," she said. The rats that had received estrogen were a lot more active that the rats that didn't receive estrogen, the researchers found. © CBC 2008

Keyword: Hormones & Behavior; Learning & Memory
Link ID: 11890 - Posted: 06.24.2010

By Emily Anthes Birds of a feather don’t just flock together—they also work together to obtain food. Recent research makes rooks the first nonprimates observed to successfully cooperate to retrieve a food-laden platform, according to a June 22 study in the journal Proceedings of the Royal Society B: Biological Sciences. Scientists at the University of Cambridge tested the rooks, which are Eurasian members of the crow family, by placing dishes of food on a platform out of reach of a bird enclosure. A single string looped from the enclosure to the platform and back again. Moving the platform closer required pulling on both ends of the string simultaneously, a feat that is only possible if two birds work together, each tugging on one end. The researchers found that rook pairs spontaneously learned how to solve the problem. “We were amazed that the rooks performed so well,” says lead author Amanda Seed, now at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. “It’s really hard to coordinate your actions. If you wait an extra second, you miss your chance.” Chimpanzees, and possibly a few other primates, are the only other species that have proved themselves capable of the same task. Rooks are extremely social birds, living in colonies of hundreds of members, and are likely to have faced evolutionary pressure to learn to cooperate, Seed says. © 1996-2008 Scientific American Inc.

Keyword: Intelligence; Evolution
Link ID: 11889 - Posted: 06.24.2010

It may not be just your diet, but how you spice it that keeps diabetes under control. A natural yellow pigment in the curry spice turmeric, already known to have other health benefits, can also improve symptoms of diabetes in mice. "Maybe obese people can become normal in their sugars without necessarily losing the weight," says physician and research scientist Drew Tortoriello. "Obviously, losing weight is the optimum way to go, but maybe along the way while they're working towards that goal we can help with a little bit of these natural remedies." Tortoriello and his colleagues fed lean mice a high fat diet and, similarly to people, they became obese and diabetic. The researchers then added a high dose of turmeric's pigment, called curcumin, to the same high fat diet of half the mice. "We noticed a very significant drop in their blood sugars. So basically after two weeks of consuming curcumin orally, their diabetes was essentially gone," says Tortoriello. He adds that the treated mice no longer had fatty livers and inflammation of the fat or adipose tissue was reduced. The mice that got the curcumin actually ate more of the food, apparently enjoying the taste. Yet, they lost a small amount of weight. And although they remained obese, these symptoms of obesity were reduced. © ScienCentral, 2000-2008.

Keyword: Obesity
Link ID: 11888 - Posted: 06.24.2010

Linda Geddes A gene variant has been identified that appears to be associated with female-to-male transsexuality – the feeling some women have that they belong to the opposite sex. While such complex behaviour is likely the result of multiple genes, environmental and cultural factors, the researchers say the discovery suggests that transsexuality does have a genetic component. The variation is in the gene for an enzyme called cytochrome P17, which is involved in the metabolism of sex hormones. Its presence leads to higher than average tissue concentrations of male and female sex hormones, which may in turn influence early brain development. Clemens Tempfer and his colleagues at the Medical University of Vienna in Austria discovered the variant after analysing DNA samples from 49 female-to-male (FtM) and 102 male-to-female (MtF) transsexuals, as well as 1669 non-transsexual controls. The variant was more common in men than women, although it doesn’t seem to be implicated in MtF transsexuality as the proportion of MtF transsexuals with it was similar to that in non-transsexual men. In women, however, there were some differences: 44% of FtM transsexuals carried it, compared with 31% of non-transsexual women. While there are many women with the variant who are not transsexual and many FtM transsexuals who lack it, the finding raises the possibility that the variant makes women more likely to feel that their bodies are of the wrong sex, and that this is a result of their brains having been exposed to higher than average levels of sex hormones during development. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior; Genes & Behavior
Link ID: 11887 - Posted: 06.24.2010

Drug addiction dramatically shifts a person’s attention, priorities, and behaviors towards a focus almost entirely on seeking out and taking drugs. Now, an animal study funded by the National Institute on Drug Abuse, part of the National Institutes of Health, has identified some of the specific long-term adaptations in the brain’s reward system that may contribute to this shift. These long-lasting brain changes may underlie the maladaptive learning that contributes to addiction and to the propensity for relapse, even after years of abstinence from the drug. The study was published in Neuron on July 30, 2008. Investigators from the University of California, San Francisco (UCSF) using an animal model of addiction, were able to distinguish brain changes in rats trained to self-administer cocaine, versus those animals that were trained to self-administer natural rewards such as food, or sucrose for several weeks. The investigators also were able to look at how much the "expectation" of receiving the drug influenced those brain changes by comparing rats trained to self-administer the drug versus animals who received the same amount of cocaine, but received it passively, i.e. they could not control their own drug taking by self-administration. It has been hypothesized that persistent drug seeking alters the brain’s natural reward and motivational system. The current study focuses on how drug seeking alters the communication between brain cells in this critical circuitry. In the normal processes of learning and memory formation there is a well documented strengthening of communication between brain cells, this process is known as "long-term potentiation" (LTP). The new study reports that LTP was similar in the rats that had learned to self administer cocaine, food or sucrose, but with a critical distinction. The increase in LTP due to cocaine persisted for up to three months of abstinence, but the increase in response to natural rewards dissipated after only three weeks. Importantly, the nature of the cocaine experience had a strong effect on the outcome, since rats exposed to cocaine when they did not expect it (passive infusions) displayed no LTP, neither transient nor long lasting.

Keyword: Drug Abuse; Learning & Memory
Link ID: 11886 - Posted: 06.24.2010

Malcolm Ritter -- Here's a couch potato's dream: What if a drug could help you gain some of the benefits of exercise without working up a sweat? Scientists reported Thursday that there is such a drug -- if you happen to be a mouse. Sedentary mice that took the drug for four weeks burned more calories and had less fat than untreated mice. And when tested on a treadmill, they could run about 44 percent farther and 23 percent longer than untreated mice. Just how well those results might translate to people is an open question. But someday, researchers say, such a drug might help treat obesity, diabetes and people with medical conditions that keep them from exercising. "We have exercise in a pill," said Ron Evans, an author of the study. "With no exercise, you can take a drug and chemically mimic it." Evans, of the Salk Institute for Biological Studies in La Jolla, Calif., and the Howard Hughes Medical Institute reports the work with colleagues in a paper published online Thursday by the journal Cell. They also report that in mice that did exercise training, a second drug made their workout much more effective at boosting endurance. After a month of taking that drug and exercising, mice could run 68 percent longer and 70 percent farther than other mice that exercised but didn't get the drug. © 2008 Discovery Communications, LLC.

Keyword: Obesity
Link ID: 11885 - Posted: 06.24.2010

Peter Aldhous You can think of it as recreating a deadly disease in the Petri dish. Scientists have grown motor neurons by "reprogramming" skin cells taken from a patient with the neurodegenerative disease amyotrophic lateral sclerosis (ALS). Now they aim to study the cells to gain a better understanding of what goes wrong in the condition, and to screen for drugs that might help prevent the damage. ALS affects cells in the spinal cord that send nerves into the muscles, controlling movement. Patients with the disease become progressively paralysed, and may eventually be unable to breathe. Famous sufferers include the US baseball player Lou Gehrig, who died of the condition in 1941, and the British theoretical physicist Stephen Hawking. Reprogrammed cells It is not possible to culture the affected cells directly from a patient's spinal cord. So researchers led by Kevin Eggan of the Harvard Stem Cell Institute, and Christopher Henderson of Columbia University, New York, took skin cells from an 82-year-old woman with ALS, and her sister, aged 89, who also has the disease. The researchers first used the genetic reprogramming technique pioneered by Shinya Yamanaka of Kyoto University in Japan to make cells known as induced pluripotent stem cells (iPS cells) from both women's skin cells. © Copyright Reed Business Information Ltd.

Keyword: Stem Cells; ALS-Lou Gehrig's Disease
Link ID: 11884 - Posted: 06.24.2010

American scientists say they are closer to understanding why some mothers suffer post-natal depression. They found mice lacking a chemical receptor in their brains developed similar symptoms. The study suggests the receptor helps stop brain cells firing too often in response to changes in hormone levels during pregnancy and birth. A British specialist said the research, published in Neuron, could lead to better treatments for the disorder. Between 5% and 25% of all new mothers are thought to suffer some form of post-natal depression, and can find it hard to cope with the demands of the baby, or even to form a bond with it. The precise reasons why some women develop it and some do not are uncertain, but the team at the University of California in Los Angeles say they may have some more answers. They focused their work on a chemical messaging system in the brain already known to play a key part in the regulation of mood and anxiety. A chemical called GABA can decrease the activity of certain nerve cells after coming into contact with receptors on that cell's surface. The Californian team noticed that a particular type of this receptor appeared to be highly active during pregnancy and the period after birth in mice. Their theory is that this variety of receptor might help, in normal circumstances, to keep control over the brain's response to huge hormonal changes during and immediately after pregnancy. Failure to do this effectively may be the root of some post-natal mood problems, they said. (C)BBC

Keyword: Depression; Hormones & Behavior
Link ID: 11883 - Posted: 07.31.2008