By Matt Kaplan Does the anticipation of sex make animals better breeders? It appears to for quails. When researchers placed male quails in environments they learned to associate with mating, the birds sired more offspring than their untrained counterparts. The findings may provide clues to the evolution of conditioned learning in a variety of animals, including humans. Conditioned learning--or conditioning--was most famously demonstrated by Ivan Pavlov more than 100 years ago. Pavlov would ring a bell and then feed a dog. After a while, the dog began salivating every time he heard the bell, suggesting he had learned to associate the sound with food. Since then, researchers have studied how conditioning develops, but few have looked at how it might have evolved. Psychologist Michael Domjan and colleagues at the University of Texas, Austin, set out to explore the question. If conditioning improves the odds of reproducing, they reasoned, the trait would be adaptive and spread through the population. The researchers placed male quails, which readily breed in captivity, in boxes with green walls or tilted floors for 5 minutes and then introduced them to a female for a romantic liaison. After 5 days of conditioning, one male was placed in a green or tilted box for 5 minutes, and another male was placed in an unfamiliar box. Then both were introduced to a single female within minutes of each other. © 2007 American Association for the Advancement of Science.

Keyword: Sexual Behavior
Link ID: 10691 - Posted: 06.24.2010

Ewen Callaway A type of drug has been found that starts working much faster against depression than current medications. Behavioural and molecular tests in rats show that the compounds kick into action in days, rather than weeks. But the drugs — called serotonin receptor agonists — won't be replacing Paxil (paroxetine) soon. None has yet been approved for treating depression in humans, and some have been scrapped because of concerns over side effects. But researchers are still keen to pursue them, because the most popular type of antidepressant, called selective serotonin reuptake inhibitors (SSRI), can take up to two months to start easing symptoms. And for one-third of people with depression, they don't work at all. "This is a very good first step in identifying and potentially having a rapidly acting antidepressant," says Ronald Duman, a drug expert at Yale University in New Haven, Connecticut. "But there's a lot of work to done." SSRI's such as Prozac have become a household name over the past three decades, garnering many millions of prescriptions every year in adults, children and even pets. The drugs work by stopping neurons from greedily keeping hold of a neurotransmitter called serotonin, so allowing more of the pleasure-providing molecule to reach protein receptors in nearby brain cells. ©2007 Nature Publishing Group

Keyword: Depression
Link ID: 10690 - Posted: 06.24.2010

Our ability to hear is made possible by way of a Rube Goldberg-style process in which sound vibrations entering the ear shake and jostle a successive chain of structures until, lo and behold, they are converted into electrical signals that can be interpreted by the brain. Exactly how the electrical signal is generated has been the subject of ongoing research interest. In a study published in the September 6 issue of the journal Nature, researchers have shed new light on the hearing process by identifying two key proteins that join together at the precise location where energy of motion is turned into electrical impulses. The discovery, described by some scientists as one of the holy grails of the field, was made by researchers at the National Institute on Deafness and Other Communication Disorders (NIDCD), one of the National Institutes of Health (NIH), and the Scripps Research Institute in La Jolla, CA. When a noise occurs, such as a car honking or a person laughing, sound vibrations entering the ear first bounce against the eardrum, causing it to vibrate. This, in turn, causes three bones in the middle ear to vibrate, amplifying the sound. Vibrations from the middle ear set fluid in the inner ear, or cochlea, into motion and a traveling wave to form along a membrane running down its length. Sensory cells (called hair cells) sitting atop the membrane "ride the wave" and in doing so, bump up against an overlying membrane. When this happens, bristly structures protruding from their tops (called stereocilia) deflect, or tilt to one side. The tilting of the stereocilia cause pore-sized channels to open up, ions to rush in, and an electrical signal to be generated that travels to the brain, a process called mechanoelectrical transduction.

Keyword: Hearing
Link ID: 10689 - Posted: 09.06.2007

By NICHOLAS BAKALAR Elderly people taking statins had fewer of the twisted nerve-cell fibers that are common in the brains of patients with Alzheimer’s disease, researchers reported last week in a study based on brain autopsies. The significance of the finding remains unclear, but this is the first time the potential effects of the cholesterol-lowering statins on brain pathology have been assessed by autopsy. Epidemiological studies of statins and Alzheimer’s have had mixed results. The researchers examined the brains of 110 men and women ages 65 to 79 who were enrolled in a larger study of dementia and had donated their brains for research. All were under 80 at enrollment, and one-third had taken statins for an average of five years before death. Simvastatin (Zocor) and lovastatin (Mevacor or Altocor) were the most common prescriptions. Even though there was no difference in the incidence of apparent dementia in statin users compared with nonusers, the statin users had fewer small brain lesions and fewer of the twisted fibers called neurofibrillary tangles, even after controlling for sex, age at death, brain weight and other variables. There was also an association between statin use and the presence of fewer amyloid plaques, the dead and dying nerve cells that are also typical of Alzheimer’s, but it did not reach statistical significance. Copyright 2007 The New York Times Company

Keyword: Alzheimers
Link ID: 10688 - Posted: 06.24.2010

By Linda Carroll Janine Geredes is the kind of person many of us love to hate. No matter how much the Northern California woman eats, she never gets fat. While the rest of us obsess over every morsel passing through our lips, convinced we’ll pack on the pounds if we let our guard down for just one moment, Geredes worries she’ll become unappealingly bony if she doesn’t eat enough. “I’ve always had to work to keep weight on,” says Geredes, 43, who is 5 feet 6 inches tall and weighs 118 pounds. “When I was a growing up I was teased for being so thin. But now, people are always saying, ‘I wish I could eat like you. You stay so thin. You must work out a ton.’ I don’t. My son and daughter are the same way. I’ve always figured it was genetic.” As it turns out, Geredes may be right. Scientists now say they have discovered the “skinny” gene. And they’ve found this lucky batch of DNA in a variety of animals, according to a report published Tuesday in the journal Cell Metabolism. "This gene is in every organism from worms to humans," says the study’s senior author, Dr. Jonathan Graff, an associate professor of developmental biology and internal medicine at the University of Texas Southwestern Medical Center. "We all have it. It's very striking." © 2007 MSNBC.com © 2007 Microsoft

Keyword: Obesity; Genes & Behavior
Link ID: 10687 - Posted: 06.24.2010

How do people become expert musicians? And why is it that, of the millions who take lessons as children, relatively few continue to play music as adults? Many people tell me they love listening to music, but their music lessons “didn’t take”. I think they are being too hard on themselves. The chasm between musical experts and everyday musicians that has grown so wide in our culture makes people feel discouraged, and for some reason this is uniquely so with music. But, although many people say their music lessons didn’t take, cognitive neuroscientists have found otherwise. Even just a small exposure to music lessons as a child creates neural circuits for music-processing that are enhanced and more efficient than in those who lack training. Lessons teach us to listen better and accelerate our ability to discern structure and form in music, making it easier for us to tell what music we like and what we don’t like. But what about that class of people we all acknowledge are true musical experts – the Alfred Brendels, Sarah Changs, Wynton Marsalises and Tori Amoses? Do they have a set of abilities – or neural structures – that are a totally different sort from those the rest of us have (a difference of kind), or do they just have more of the same basic stuff all of us are endowed with (a difference of degree)? And do composers and songwriters have a fundamentally different set of skills from players? © Copyright 2007 Times Newspapers Ltd.

Keyword: Hearing
Link ID: 10686 - Posted: 06.24.2010

Michael Hopkin The genes that underpin schizophrenia may have been favoured by natural selection, according to a survey of human and primate genetic sequences. The discovery suggests that genes linked to the debilitating brain condition conferred some advantage that allowed them to persist in the population — although it is far from clear what this advantage might have been. Researchers led by Bernard Crespi of Simon Fraser University in Burnaby, Canada, examined 76 DNA sequences linked to schizophrenia. They compared these human sequences with one another and with those of primates such as chimps and macaques, as well as with some from mice, rats, cows and dogs. Of the 76 genes studied, 28 showed evidence of being favoured by natural selection. They showed less variation than other control sequences from elsewhere in the genome, and had less evidence of having been jumbled up by the random mixing of genes that occurs during sexual reproduction. These findings suggest that these schizophrenia-linked sequences may have conferred an evolutionary advantage, the researchers explain in Proceedings of the Royal Society B1. The genetic data provide no clues as to the kind of advantage that schizophrenia-linked genes might have offered. "That is the big question and we don't really have a good answer to that," admits Crespi's colleague Steve Dorus of the University of Bath, UK. ©2007 Nature Publishing Group

Keyword: Schizophrenia; Genes & Behavior
Link ID: 10685 - Posted: 06.24.2010

By Constance Holden Scientists are excited over what they see as a possible breakthrough in the treatment of schizophrenia: the first human trials showing efficacy for a completely new class of antipsychotic drugs. The study represents the "leading edge of a new generation of medications" for schizophrenia, says Yale University drug researcher John Krystal. Over the past half-century, many drugs have been introduced to treat schizophrenia, which afflicts about 1% of the population. But all of them have activity at the same target: the D2 dopamine receptor. The "dopamine hypothesis" is based on the fact that excess dopamine causes psychosis. In recent years, however, scientists have been probing another theory, the "glutamate hypothesis." Glutamate is the brain's main excitatory neurotransmitter and activates other neurochemicals. The theory is that low activity in a certain type of glutamate receptor (NMDA) paradoxically leads to excess glutamate elsewhere, damaging brain connections. This results in psychosis, thought disorder, and the dulling of emotions associated with schizophrenia. In animal studies, compounds that act on glutamate receptors seem to block the effects of psychosis-mimicking amphetamines better than do most conventional drugs. In a paper published online Sunday in Nature Medicine, researchers from Eli Lilly and Co. in Indianapolis, Indiana, have shown that these compounds work in humans as well. © 2007 American Association for the Advancement of Science

Keyword: Schizophrenia
Link ID: 10684 - Posted: 06.24.2010

Mary Muers Eating as much as you like but never getting fat sounds like a dieter's dream. But it's a reality for mice missing a key gene, researchers have found. These mice set up a futile cycle of making and breaking unnecessary proteins, burning fat along the way. As a result they eat more food but weigh less than normal mice. The discovery has raised hopes of novel ways to tackle obesity and diabetes. The missing gene in this case codes for an enzyme needed to chemically digest some amino acids — the building blocks of proteins. This results in the build-up of an amino acid called leucine, which in turn tricks cells into making new, unnecessary proteins and then destroying them. This pointless cycle burns up excess calories so the mice stay trim, regardless of the extra food they munch. Obesity results from an imbalance in the simple equation of energy input versus energy output, because excess fuel is turned into fat. The notion that making and breaking down biological molecules can waste spare calories is not new to scientists; it has been posited as an explanation for why some lucky people can naturally eat more but stay slim. But this study, published in Cell Metabolism1 today, is the first time wasteful protein turnover has been shown in practice. ©2007 Nature Publishing Group

Keyword: Obesity
Link ID: 10683 - Posted: 06.24.2010

Men look for beauty, while women go for wealth when it comes to assessing future partners, researchers say. An Indiana University team looked at the behaviour of 46 people taking part in a speed-dating session. They found that the men were more likely to go for the more attractive women, while women opted for those who could give the best financial security. Men were also likely to want to date more women, the Proceedings of the National Academy of Sciences reported. Speed-dating is becoming an increasingly popular way for singles to meet, involving scores of mini-dates whereby couples get a few minutes to get to know each other. Researchers said speed-dating offered a good model to analyse the factors people take into account when choosing partners as it offered a "microcosm" of daily life. During the research, participants were asked what they were looking for. The most common response was to find someone who was like themselves. But once the speed-dating sessions began, participants began conforming to set patterns, according to the analysis of questionnaires filled in. The report said men sought the more attractive women and the women were drawn to material wealth and security. Furthermore, while men on average wanted to see every second woman again, the women wanted to meet only a third of men. Lead researcher Peter Todd said the study showed the public reverted to type when choosing a mate. "While humans may pride themselves on being highly evolved, most still behave like the stereotypical Neanderthals when it comes to choosing a mate. " (C)BBC

Keyword: Sexual Behavior; Evolution
Link ID: 10682 - Posted: 09.04.2007

By BEN DAITZ, M.D. ALBUQUERQUE, In 1598, Joyce Gonzalez’s great- great- great- great -great -great -great -great -great -great -grandfather followed the famous conquistador Juan de Oñate from Spain to Mexico, then north on the Camino Real, the Royal Road to Santa Fe. In the 1800s, one of Mary Ann Chavez’s distant relatives, possibly a French fur trapper and trader from Quebec, also made his way into northern New Mexico. Mrs. Chavez and Mrs. Gonzalez, though not related, share a Hispanic heritage and a fascination with genealogy. They also share the burden of having forebears with genetic diseases that, like the remote mountain villages in this region, have remained largely hidden from medical diagnosis and treatment. Now, thanks to the efforts of patient advocates and the work of a clinic here at the University of New Mexico Medical School, these illnesses are finally being confronted and studied. “We call it the family curse,” said Mrs. Chavez, 73, “and you don’t know you’ve got it until you’re 40 or 50 when your eyelids start to droop, and you begin to have trouble swallowing and get muscle weakness.” The illness is called oculopharyngeal muscular dystrophy, or OPMD, and the largest group of Americans affected are Hispanics living in northern New Mexico. They are descendants of the wandering French-Canadian or, perhaps, early Spanish colonists. Mrs. Chavez’s son, her brother and innumerable aunts, uncles and cousins have all inherited the disease. Copyright 2007 The New York Times Company

Keyword: Movement Disorders; Genes & Behavior
Link ID: 10681 - Posted: 06.24.2010

By ANAHAD O’CONNOR Few foods have a reputation for curing insomnia quite like warm milk. According to age-old wisdom, milk is chock full of tryptophan, the sleep-inducing amino acid that is also well known for its presence in another food thought to have sedative effects, turkey. But whether milk can induce sleep is debatable, and studies suggest that if it does, the effect has little to do with tryptophan. To have any soporific effect, tryptophan has to cross the blood-brain barrier. And in the presence of other amino acids, it ends up fighting — largely unsuccessfully — to move across. One study by researchers at the Massachusetts Institute of Technology demonstrated this in 2003. The study, which was published in The American Journal of Clinical Nutrition, showed that eating protein-rich foods — like milk — decreased the ability of tryptophan to enter the brain. The trick, the study showed, is to eat foods high in carbohydrates, which stimulate the release of insulin. Insulin, in turn, makes it easier for tryptophan to enter the brain. Copyright 2007 The New York Times Company

Keyword: Sleep
Link ID: 10680 - Posted: 06.24.2010

By BENEDICT CAREY The number of American children and adolescents treated for bipolar disorder increased 40-fold from 1994 to 2003, researchers report today in the most comprehensive study of the controversial diagnosis. Experts say the number has almost certainly risen further since 2003. Many experts theorize that the jump reflects that doctors are more aggressively applying the diagnosis to children, and not that the incidence of the disorder has increased. But the magnitude of the increase surprises many psychiatrists. They say it is likely to intensify the debate over the validity of the diagnosis, which has shaken child psychiatry. Bipolar disorder is characterized by extreme mood swings. Until relatively recently, it was thought to emerge almost exclusively in adulthood. But in the 1990s, psychiatrists began looking more closely for symptoms in younger patients. Some experts say greater awareness, reflected in the increasing diagnoses, is letting youngsters with the disorder obtain the treatment they need. Copyright 2007 The New York Times Company

Keyword: Schizophrenia; Depression
Link ID: 10679 - Posted: 09.04.2007

By JAMIE TALAN Hailey Ems was born weeks early, on the floor of an upstairs bathroom as emergency medical technicians huddled on a staircase trying to figure out how to get the stretcher upstairs. When she didn’t meet the normal developmental milestones of the first year — crawling, standing and finding her first words — doctors tested her for cerebral palsy and muscular dystrophy. Nothing turned up positive. Finally, it was her 10-year-old brother who announced one day, “I don’t think Hailey can hear.” She was 14 months old, and her brother was right. Had Hailey been born in the hospital, she would have been given a hearing test. When she arrived in 2001, such screening was voluntary but routine in the Cincinnati hospital where her mother, Mary, intended to give birth; today, it is mandatory in 40 states and commonly performed in the other 10. But hearing specialists worry that many deaf or hearing-impaired babies who fail the screening are not making it to the next level of testing — a more vigorous hearing exam in which an audiologist uses an EEG-like machine that records the brain’s response to sound. Copyright 2007 The New York Times Company

Keyword: Hearing; Development of the Brain
Link ID: 10678 - Posted: 06.24.2010

By LINDA SIMON One night, sitting in the dark in my car, I see, out of the corner of my eye, something flashing. An emergency vehicle has pulled up behind me, I think, the lights on its roof spinning ominously. It has come to retrieve a body, to speed someone to the hospital, to gather the injured. I turn my head, expecting to see a disaster. But nothing is there. Just the flashing. I know this is not a good sign. The next morning, in a room flooded with sunlight, there is another development: shadowy spots tumble and swirl, as if tenacious, persistent flies were circling my head. Eye floaters are common, of course, and I have noticed them before, but never like this. Now I am assaulted by shadows that come and go and come again. They swarm like a plague, like warnings of darkness. I present myself to the doctor for investigation: myself, which overnight has become my eye. First it is numbed, then the pupil is dilated, then it is peered into through a special magnifying lens. I sit in the dark examining room and think dark thoughts. The flashes flash from time to time, capriciously, or maybe urgently. The eye doctor looks intently. How are you doing? he asks; You’re doing well, he answers. I do not reply except to comment, Not so well, really. Copyright 2007 The New York Times Company

Keyword: Vision
Link ID: 10677 - Posted: 06.24.2010

By HENRY FOUNTAIN Cats may live in their own world, but they have to survive in this one. So when walking, they are no different from humans or other animals: they use vision to create short-term memories. Even if visual input is removed, studies have shown, a cat can go several steps among obstacles before losing its way. But to really remember something, David A. McVea and Keir G. Pearson of the University of Alberta report in the journal Current Biology, a cat has to do, rather than see. The act of stepping over an object can make for a long-lasting memory of it. Mr. McVea said the work built on their previous research showing that cats remembered information about an obstacle even after it was removed. They had cats step their forelegs over a three-inch barrier, then distracted the animal while the barrier was lowered. When the cat moved again, it raised its rear legs as if the barrier were still there. “That memory of that obstacle lasts for as long as that cat stands there,” Mr. McVea said, though because of the difficulties of herding cats, the longest they were able to distract one was 10 minutes. Copyright 2007 The New York Times Company

Keyword: Learning & Memory
Link ID: 10676 - Posted: 06.24.2010

By Sally Squires Alcohol, nicotine and cocaine are a few of the substances known to be addictive. Now some scientists wonder whether food should be added to the list. "Are there certain things in food that act on the brain and set up a classic addictive process, like tolerance, withdrawal and craving?" asks psychologist Kelly Brownell, who organized a recent scientific meeting on food addiction at Yale University. While the research is still scanty, the evidence that exists "is extremely interesting and provocative, and suggests to me that something is there," Brownell says. That's not news to the many Lean Plate Club members who recently e-mailed me about their own food struggles. Most asked not to be named, reflecting the sense that they feel stigmatized by behaviors they have trouble controlling. "I feel addicted to food at times," one wrote. "Food is like a drug to me. It can change my emotional state. For many years, I have 'used' food as a feel-good panacea, self-medicating with warm chocolate chip cookies or a pint of Chunky Monkey. I will sit down with a food I like in an upset state of mind and will eat it all immediately, beyond the feeling of fullness. It's like a compulsion to finish the entire thing." © 2007 The Washington Post Company

Keyword: Obesity; Drug Abuse
Link ID: 10675 - Posted: 06.24.2010

Carl Zimmer William McGrew spent much of the 1970s observing chimpanzees in Tanzania. One day the chimps did something odd. As two chimpanzees groomed each other's hair, they each lifted an arm overhead. They clasped hands, forming a kind of primate A-frame. McGrew and his collaborator, Caroline Tutin, had just spent months observing another chimpanzee community just a hundred miles away, and they had never seen that gesture before. But at their new field site, the A-frame handshake turned out to be common. A special chimpanzee handshake may not seem like much of a discovery, but McGrew realized that it could change the way we think about human nature itself. In our own species, handshakes are a sign of culture. Travel the world, and you'll find a dizzying range of handshakes and other forms of greeting, from the military salute to the cheek kiss, to the high five, to the hongi of New Zealand--pressing noses to exchange a sacred breath. These greetings are not hard-wired into our genomes. Each one was invented in a particular place and time, and then spread from one person to another. It's the same process that has given rise to all the cultural variation that makes humans so endlessly interesting, from languages to dances to technology. Biologists long believed that culture is unique to humans, because it depended on qualities that only humans were believed to possess--things like the capacity for language and imitation. Animals simply acted on individual instinct; they couldn't follow trends. And yet McGrew saw what looked like a local chimpanzee custom. © 2007 Forbes.com LLC™

Keyword: Evolution; Language
Link ID: 10674 - Posted: 06.24.2010

By MALCOLM RITTER NEW YORK -- Scientists are casting a wide net to find better treatments for the crushing depression and uncontrolled manias of bipolar disorder, and some approaches they're testing seem pretty surprising. Like skin patches that prevent seasickness. Or a drug that fights Lou Gehrig's disease. And then there's a newly invented device that resembles a hair dryer in a beauty salon. Some of the strategies were identified by logic, and others by pure chance. Scientists already have evidence that they may someday prove useful against bipolar disorder, also called manic-depression. Doctors yearn for better therapies to treat the condition, which can rip careers and marriages apart and drive people to suicide. It is so complex and mysterious that researchers haven't developed a medication specifically for it since lithium, more than half a century ago. Bipolar disorder appears in various forms and degrees of severity in about one in every 25 American adults at some point in their lives, according to a major study published in May. The disorder is characterized in part by episodes of mania, which are periods of boosted energy and restlessness that can run for a week or more. © 2007 The Associated Press

Keyword: Schizophrenia
Link ID: 10673 - Posted: 06.24.2010

Alison Abbott Psychiatrists have welcomed the unveiling by a US drug company of the first new class of schizophrenia drugs since the 1950s. According to early clinical-trial data, the prototype drug — codenamed LY2140023 and produced by Eli Lilly researchers in Indianapolis, Indiana — seems to be as effective as olanzapine, the best currently available drug. The drug's developers hope that it will offer psychiatrists a new alternative for treating their patients, and one that may offer greater benefits in relation to the side effects. According to the World Health Organization, schizophrenia affects around 1% of the population worldwide. Its broad range of debilitating symptoms can include delusions, hallucination, disordered thinking, social withdrawal and emotional 'flatness'. Current anti-schizophrenia drugs all work the same way, by reducing levels of the neurotransmitter dopamine in the brain. But they do not control the disease well in all patients and often have unpleasant side effects. The new drug, LY2140023, is converted in the body into a second compound, called LY404023, which acts by damping down the activity of a different neurotransmitter, glutamate. Lilly researchers say that the trial is an important proof of principle that their new approach to the disease works, but they don't yet know if this particular compound will make it into the clinic. "Our study is the first conclusive evidence for a role of glutamate in the pathophysiology of schizophrenia," says James Monn, one of the research team. ©2007 Nature Publishing Group

Keyword: Schizophrenia
Link ID: 10672 - Posted: 06.24.2010