Lab experiments suggest that a pregnant mother's exposure to certain chemicals in the environment can cause reproductive problems not only for her own children, but also for several more generations of her family. As this ScienCentral News video explains, research with pregnant rats revealed what genetics researchers thought was impossible. One chemical is used in insecticides. The other is a fungicide used on vineyards and orchards. They are known to alter levels of reproductive hormones, but there were no signs — until now — that such chemicals could alter our genes — the DNA code we pass on to our children. "We've made a discovery that has made us sit back and think about some general biology questions in a number of different areas," says biologist Michael Skinner, director of Washington State University's Center for Reproductive Biology. "If disease can be induced by environmental factors, and then subsequently be carried forward to the subsequent generations, then we have come up with potentially a new paradigm for disease development." When Skinner gave high doses of the chemicals to pregnant rats, he discovered sperm count problems in 90 percent of all male descendants over the next four generations. Something he calls a "transgenerational phenomenon." © ScienCentral, 2000-2006.

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 8376 - Posted: 06.24.2010

A team of researchers, led by investigators at Washington University School of Medicine in St. Louis, has found that a gene variant for a bitter-taste receptor on the tongue is associated with an increased risk for alcohol dependence. The research team studied DNA samples from 262 families, all of which have at least three alcoholic individuals. The families are participating in a national study called the Collaborative Study of the Genetics of Alcoholism (COGA). COGA investigators report in the January issue of the American Journal of Human Genetics on the variation in a taste receptor gene on chromosome 7 called TAS2R16. "In earlier work, we had identified chromosome 7 as a region where there was likely to be a gene influencing alcoholism risk," says principal investigator Alison M. Goate, D. Phil., the Samuel and Mae S. Ludwig Professor of Genetics in Psychiatry at Washington University. "There's a cluster of bitter-taste receptor genes on that chromosome, and there have been several papers suggesting drinking behaviors might be influenced by variations within taste receptors. So we decided to look closely at these taste receptor genes." Because taste receptors tend to vary a lot in the general population, Goate and colleagues had the opportunity to look at a large number of differences in genetic sequences and determine whether certain sequences might influence risk. In this study, they concentrated on TAS2R16, which helps regulate the response to bitter tastes. They found a single base variation in the TAS2R16 receptor gene that seemed to put people at an increased risk for alcoholism. In cell culture experiments, Goate found that the variant receptor produced by this gene was less responsive to bitter compounds.

Keyword: Chemical Senses (Smell & Taste); Drug Abuse
Link ID: 8375 - Posted: 01.11.2006

By Amy R. Coombs As anyone on a new year's diet can attest, gaining weight is much easier than burning it off. Humans aren't the only ones capable of packing on the pounds, however. New research indicates that insects store fat in one of the same ways mammals do. Identifying the fat management pathways insects and mammals have in common may eventually help scientists develop new ways to fight obesity, say the researchers. Fat cells form when a unique class of stem cells make a critical decision: They either become osteoblasts, which develop into bone cells, or preadipocytes, which give rise to fat cells. Exactly which messages tell a stem cell to become a fat cell rather than a bone cell remain a mystery, however. To learn more about the process, Jonathan Graff, a molecular biologist at the University of Texas Southwestern Medical Center in Dallas, studied a set of genes known to impact development in humans, flies, and many other animals. To see if the set, called the Hedgehog suite, also influences the development of fat cells, Graff and his research team bred mutant flies missing select Hedgehog genes. Flies without the genes were fatter, survived starvation better, and had higher overall levels of lipid and fat related proteins than did flies with an intact gene suite, the team reports this month in Cell Metabolism. © 2006 American Association for the Advancement of Science.

Keyword: Obesity
Link ID: 8374 - Posted: 06.24.2010

Researchers at Rutgers, The State University of New Jersey, believe they have located a place in the brain where songbirds store the memories of their parents' songs. The discovery has implications for humans, because humans and songbirds are among the few animals that learn to vocalize by imitating their caregivers. In a paper published today in the Proceedings of the National Academy of Sciences, David Vicario and Mimi Phan of Rutgers, and Carolyn Pytte of Wesleyan University, report that songbirds store the memory of caregivers' songs in a part of the brain involved in hearing. This suggests the auditory version of the caregiver's song is stored first, and that it may serve to guide the vocal learning process. The paper is titled "Early Auditory Experience Generates Long-Lasting Memories That May Subserve Vocal Learning in Songbirds." "There is independent evidence, notably from work done by Patricia Kuhl of the University of Washington in Seattle, that something similar may underlie the acquisition of human speech by infants and, thus, be part of the mechanism that allows kids to learn any human language if they start early enough," Vicario says. Vicario, Phan and Pytte worked with zebra finches, tiny songbirds native to Australia and favored by researchers because they breed well in captivity and all year- round. There are other animals that also learn vocalizations by imitating members of their species – whales, dolphins and parrots, for instance – but they take a long time to mature, are endangered or are too difficult to work with in laboratories.

Keyword: Language; Sexual Behavior
Link ID: 8373 - Posted: 06.24.2010

Helen Pearson If you're the type to stumble about as though drunk on first getting out of bed, scientists can now back up your behaviour as reasonable. A team has shown that people are as woozy when they wake as they are after drinking several beers. Sleep researchers have long been interested in the symptoms of sluggishness and disorientation that people experience after awakening, which they call sleep inertia. Now they have measured exactly how hopeless our early-morning brains are at carrying out everyday tasks. To do this, Kenneth Wright at the University of Colorado, Boulder, and his co-workers looked at the mental handicap caused by sleep inertia, and compared it with the detriment of having stayed up all night. They allowed nine volunteers to enjoy roughly eight hours' nightly slumber for four weeks, the final week taking place in the lab. After a final pleasant night's sleep, they woke each person and immediately, without even a cup of coffee, asked them to calculate a string of sums. A minute after waking, they scored how many problems each one totted up correctly over two minutes. The test was then repeated after 20 minutes and again at regular intervals until the subjects had gone a full 26 hours without sleep. ©2006 Nature Publishing Group

Keyword: Sleep
Link ID: 8372 - Posted: 06.24.2010

By Eric Jaffe "If we find any gross abnormalities in your brain, would you like a radiologist to tell you about it?" Tobias Egner asks me. He is about to wheel me into the dark gullet of an fMRI machine at the Functional MRI Research Center at Columbia University, a leading neuroscience lab where he is a research fellow. I say yes to his question and ask if anyone ever says no. "If you answer no, we cannot do the test," Egner says. He speaks with a soft certainty and a German accent; if this were a movie, he'd be played by Willem Dafoe, a la The Life Aquatic With Steve Zissou. "Ready to roll?" In the last decade, fMRI (or functional magnetic resonance imaging) has become a premier—and scrutinized—tool of neuroscience. I wanted to see for myself how the technology works. On a visit to Columbia's lab to view an experiment, I mentioned an interest in participating, and two researchers within earshot accepted my offer. I signed on with Egner to become one of about 20 subjects in a study of how the brain manages conflicting information. To me, this means choosing every night at 7 between the Seinfeld rerun on Fox and the one on TBS. To Egner, it means studying how the amygdala, the brain's emotional hub, resolves the millions of emotional conflicts people experience every day. To watch my mind in action, Egner will use the fMRI machine's magnetic coil to scan my brain every two seconds for blood rushes, which show an increase in neural activity. The more common MRI uses magnetic resonance imaging to scan the body for abnormal tissue, in order to diagnose a tumor or an injury. The added "f" for functional means the machine will look at my brain while I perform mental tasks, so it can see which regions are most active. From a control room facing me, Egner will capture the results on a computer. ©2005 Washingtonpost.Newsweek Interactive Co. LLC

Keyword: Brain imaging
Link ID: 8371 - Posted: 06.24.2010

By Ker Than A new study finds that a cell once believed to serve neurons instead may perform the crucial function of regulating blood flow in the brain. The discovery challenges a basic assumption in neuroscience and could have implications for interpreting brain scans and understanding what occurs during brain trauma and Alzheimer's disease. Oxygen is the main fuel of biological cells. It is transported throughout the body by way of the circulatory system. Not surprisingly, the brain is one of the most voracious consumers of oxygen, and a basic assumption in neuroscience is that the more active a brain region is, the more oxygen (and thus blood) its neurons require. This assumption forms the foundation for sophisticated brain imaging techniques such as PET and functional MRI scans. By scanning the brain while subjects perform certain tasks, scientists have been able to pinpoint specialized brain regions for phenomena such as emotion or language. Star-shaped brain cells called astrocytes were traditionally thought of as housekeeping cells that helped nourish the brain under the direction of the neurons. The new study found that the astrocytes can directly control blood flow without being told. 2006 LiveScience.com.

Keyword: Glia; Brain imaging
Link ID: 8370 - Posted: 01.11.2006

By CRAIG SMITH ALBERT Hofmann, the father of LSD, walked slowly across the small corner office of his modernist home on a grassy Alpine hilltop here, hoping to show a visitor the vista that sweeps before him on clear days. But outside there was only a white blanket of fog hanging just beyond the crest of the hill. He picked up a photograph of the view on his desk instead, left there perhaps to convince visitors of what really lies beyond the windowpane. Mr. Hofmann will turn 100 on Wednesday, a milestone to be marked by a symposium in nearby Basel on the chemical compound that he discovered and that famously unlocked the Blakean doors of perception, altering consciousnesses around the world. As the years accumulate behind him, Mr. Hofmann's conversation turns ever more insistently around one theme: man's oneness with nature and the dangers of an increasing inattention to that fact. "It's very, very dangerous to lose contact with living nature," he said, listing to the right in a green armchair that looked out over frost-dusted fields and snow-laced trees. A glass pitcher held a bouquet of roses on the coffee table before him. "In the big cities, there are people who have never seen living nature, all things are products of humans," he said. "The bigger the town, the less they see and understand nature." And, yes, he said, LSD, which he calls his "problem child," could help reconnect people to the universe. Copyright 2006 The New York Times Company

Keyword: Drug Abuse
Link ID: 8369 - Posted: 01.07.2006

By JR Minkel In 2002 a clinical trial of an experimental Alzheimer's vaccine was halted when a few patients began experiencing brain inflammation, a result of the immune system mounting an attack against the body. Now some researchers claim that inducing a mild autoimmune reaction could actually protect the central nervous system from a spectrum of neurodegenerative conditions, from glaucoma and spinal cord injury to Parkinson's and Alzheimer's disease. "This is a hot-button issue right now," says Howard Gendelman of the University of Nebraska Medical Center in Omaha. It all started with glaucoma. Once thought to result primarily from high pressure in the eyeball constricting the optic nerve, the disease has lately come to be seen as a form of neurodegeneration, propagating from the injured optic nerve to healthy cells in the brain. Before monkey studies had demonstrated as much, neuroimmunologist Michal Schwartz of the Weizmann Institute in Rehovot, Israel, observed in the late 1990s that crushing a small portion of a rat optic nerve creates a large zone of sickened cells. She and her team also found that T cells, the immune system's attackers, gathered at these wounds. © 1996-2006 Scientific American, Inc.

Keyword: Neuroimmunology; Regeneration
Link ID: 8368 - Posted: 06.24.2010

By Carolyn Gramling Pound for pound, females appear to be better at holding their liquor than males, and now scientists may have found one reason why. A new study in rats suggests that hormone levels in the brain may mediate alcohol's potency, giving females a leg up at certain times during their hormonal cycle. The gender gap in alcohol metabolism is no secret. Women metabolize alcohol more slowly than men and that makes them more susceptible to alcoholic liver disease, heart muscle damage, and brain damage. Rat studies suggest that males and females in their teenage years are equally affected by the equivalent of a stiff drink, but females are less sensitive to alcohol's sedative powers when they become adults. And, given an open "tab," female rats drink more than the males, but their consumption varies across their hormonal cycle. These findings suggest that hormone levels may mediate alcohol's potency, say H. Scott Swartzwelder of Duke University Medical Center in Durham, North Carolina. To examine this link more closely, Swartzwelder and colleagues studied the sedative effects of alcohol by injecting the equivalent of about 20 drinks of alcohol into adolescent and adult rats of both genders and throughout the females' estrous cycle. The researchers then observed how long it took for the rats to stand up on all four feet from a prone position. © 2005 American Association for the Advancement of Science.

Keyword: Drug Abuse; Sexual Behavior
Link ID: 8367 - Posted: 06.24.2010

By Dennis O'Brien Do you generally trust other people? How do you react when you're frightened? Are you faithful to your spouse? The answer to these loaded questions may be tied to a natural chemical known mainly for helping mothers give birth. It's called oxytocin, and it's released by the brain during labor and to stimulate milk during breast feeding. Doctors have used a synthetic version for decades to induce contractions in pregnant women. Researchers also have linked increased levels of the so-called "attachment hormone" to sexual activity and the reaction to a good massage. "It's pretty wild stuff," said Dr. Thomas Insel, an oxytocin expert who is director of the National Institute of Mental Health. Last month, NIMH researchers published research involving 15 men whose brains were scanned after they sniffed oxytocin and then viewed several photos of threatening or frightened faces. The scans recorded two-thirds less activity in their amygdalae - the brain region that registers fear - than a control group that wasn't exposed to oxytocin. Differences were greatest when the men looked at threatening faces, suggesting the hormone plays a key role in regulating fear. © 2006 by The Baltimore Sun.

Keyword: Hormones & Behavior; Emotions
Link ID: 8366 - Posted: 06.24.2010

Babies exposed to certain infections shortly before and after birth have a greater risk of cerebral palsy, Australian research suggests. Scientists tested over 1,300 babies, including 443 with cerebral palsy, for viruses, including the herpes group B virus, which can cross the placenta. The British Medical Journal study showed the cerebral palsy risk doubled with exposure to herpes group B virus. Cerebral palsy can cause physical impairments and mobility problems. It results from the failure of a part of the brain to develop before birth or in early childhood or brain damage and affects one in 400 births. The team from the Adelaide Women's and Children's Hospital found exposure to viral infections was common in all newborns - especially if they were born premature. This implied infections before birth may also be linked to pre-term delivery, the researchers said. But the team concluded only exposure to the herpes B virus, which causes chicken pox and shingles, seemed to be linked with cerebral palsy. A different herpes virus, group A, causes common cold sores and genital herpes. However, the researchers added that other factors such as growth restriction, clinical events and genetic susceptibility to infections could be a factor and plan to look at these in further research. (C)BBC

Keyword: Development of the Brain; Movement Disorders
Link ID: 8365 - Posted: 01.07.2006

Female hormones circulating in the brain determine masculine behavior, at least in mice. Estrogen--the quintessential female hormone responsible for regulating the reproductive cycle--turns lady mice into wannabe male mice when it is allowed to penetrate the brain during development, according to new research. Neuroscientist Julie Bakker of the University of Liege in Belgium and her colleagues proved this in the course of solving one of the longstanding riddles of brain development. Although it had long been known that a certain protein--alpha-fetoprotein (AFP)--plays a key role in mouse brain development by binding to estrogen, it was unclear whether AFP facilitates the development of female brains by carrying the hormone or simply by blocking it from entering the brain. The scientists used female mice incapable of producing AFP and set them loose in a Plexiglass aquarium with a sexually active male. To give them extra incentive to mate, they also received injections and capsules of female hormones. But, unlike their wild cousins, the AFP-deficient mice showed little interest in the male's advances and their brains had fewer cells devoted to producing certain chemicals critical to reproduction, just like males. Furthermore, when placed in a cage with a sexually receptive female, the mice without AFP tried to mimic their male counterparts by mounting the female and engaging in pelvic thrusting. © 1996-2006 Scientific American, Inc.

Keyword: Sexual Behavior
Link ID: 8364 - Posted: 06.24.2010

A new device for detecting suspicious odors has an unusual component. Its brain consists of five tiny trained wasps. Their trainer, agricultural engineer Glen Rains, admits the idea may sound far-fetched at first. "I initially thought some people would kind of look at it like uh some kind of like a flea circus type thing," says Rains, associate professor at the University of Georgia. But as he wrote in the journal Biotechnology Progress, the sensor is cheaper to use than trained dogs and more sensitive than some electronic noses. Rains uses parasitic wasps that don't have stingers but do have sensitive sniffers. They've been studied for years for use in biological pest control. "We were trying to come up with ways to improve their efficiency for foraging… it turned out that they use their sense of smell to find food and hosts, filter out all this information they find in the field very, very efficiently," Rains says. Further study showed that the wasps actually learn odors in the field as they get positive or negative reinforcement. © ScienCentral, 2000-2006.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 8363 - Posted: 06.24.2010

A protein that seems to be pivotal in lifting depression has been discovered by a Nobel Laureate researcher funded by the National Institutes of Health's National Institute of Mental Health (NIMH). "Mice deficient in this protein, called p11, display depression-like behaviors, while those with sufficient amounts behave as if they have been treated with antidepressants," explained Paul Greengard, Ph.D., a Rockefeller University neuroscientist who received the 2000 Nobel Prize in Physiology or Medicine for discoveries about the workings of such neuronal signaling systems. He and his colleagues found that p11 appears to help regulate signaling of the brain messenger chemical serotonin, a key target of antidepressants, which has been implicated in psychiatric illnesses such as depression and anxiety disorders. They report on their findings in the January 6, 2005 issue of Science. Brain cells communicate with each other by secreting messengers, such as serotonin, which bind to receptors located on the surface of receiving cells. Serotonin selective reuptake inhibitors (SSRIs), medications commonly prescribed for anxiety and depression, compensate for reduction in serotonin signaling by boosting levels and binding of serotonin to receptors. Previous studies have suggested that serotonin receptors are essential in regulating moods and in mediating the effects of SSRIs, but given the complexity of the serotonin system, exactly how these receptors work remains a mystery.

Keyword: Depression; Genes & Behavior
Link ID: 8362 - Posted: 01.05.2006

RICHMOND, Va. – Virginia Commonwealth University researchers have found that genes contribute more strongly to the risk of depression in women than in men, and that there may be some genetic factors that are operating uniquely in one sex and not in the other. In the January issue of the American Journal of Psychiatry, researchers reported that heritability of depression is higher in women – approximately 42 percent -- than in men, where it is approximately 29 percent. “Our work, together with colleagues at the Karolinska Institute in Sweden, represents the largest epidemiological study of depression in twins done to date. In addition, it broadly replicates what has been shown by our earlier work using the Virginia Twin Registry. In particular, we have shown that depression is a moderately heritable disorder, suggesting that genetic factors are important, but by no means overwhelming,” said Kenneth S. Kendler, M.D., a professor of psychiatry and human genetics in VCU’s School of Medicine and lead author on the study. The research team employed twin study models to evaluate lifetime major depression of approximately 42,000 twins, including 15,000 complete pairs from the Swedish National Twin Registry.

Keyword: Depression; Sexual Behavior
Link ID: 8361 - Posted: 06.24.2010

THE US Department of Defense has revealed plans to develop a lie detector that can be used without the subject knowing they are being assessed. The Remote Personnel Assessment (RPA) device will also be used to pinpoint fighters hiding in a combat zone, or even to spot signs of stress that might mark someone out as a terrorist or suicide bomber. In a call for proposals on a DoD website, contractors are being given until 13 January to suggest ways to develop the RPA, which will use microwave or laser beams reflected off a subject's skin to assess various physiological parameters without the need for wires or skin contacts. The device will train a beam on "moving and non-cooperative subjects", the DoD proposal says, and use the reflected signal to calculate their pulse, respiration rate and changes in electrical conductance, known as the "galvanic skin response". "Active combatants will in general have heart, respiratory and galvanic skin responses that are outside the norm," the website says. Because these parameters are the same as those assessed by a polygraph lie detector, the DoD claims the RPA will also indicate the subject's psychological state: if they are agitated or stressed because they are lying, for example. So it will be used as a "remote or concealed lie detector during prisoner interrogation". © Copyright Reed Business Information Ltd.

Keyword: Stress
Link ID: 8360 - Posted: 06.24.2010

The Who guitarist Pete Townshend has warned music fans against potential hearing damage caused by headphones as portable players become more popular. The 60-year-old said studio headphones caused his hearing problems, rather than playing loudly on stage. "I have unwittingly helped to invent and refine a type of music that makes its principal proponents deaf," Townshend wrote on his website. My intuition tells me there is terrible trouble ahead." Townshend, who is preparing to tour with the Who this year, said he discovered he had "badly damaged" his hearing in the 1970s. "My ears are ringing, loudly," he wrote. "My own particular kind of damage was caused by using earphones in the recording studio, not playing loud on stage." He said he must take 36-hour hearing rests while recording a new album with fellow Who member Roger Daltrey, breaks he describes as "frustrating and agonising, but compulsory". (C)BBC

Keyword: Hearing
Link ID: 8359 - Posted: 01.04.2006

Some clinical studies have indicated that marijuana or its active cannabinoid ingredient alleviates symptoms of the inflammatory disease multiple sclerosis (MS). Also, researchers have found that the brain's natural "endocannabinoids" are released after brain injury and are believed to alleviate neuronal damage. However, scientists have not understood how such substances act within the brain's own immune system. Now, experiments by Oliver Ullrich and colleagues have pinpointed how one of the brain's endocannabinoids protects neurons from inflammation after such damage. They say their studies could lead to new drugs to treat the inflammation and brain degeneration from MS or other such disorders. In an article in the January 5, 2006, issue of Neuron, the researchers reported experiments showing how the endocannabinoid anandamide (AEA) protects brain cells from inflammation. Such a role in the brain's immune system is distinct from cannabinoids' effects on neuronal signaling that produce the behavioral effects of marijuana. When Ullrich and colleagues analyzed brain tissue from people with MS, they found elevated levels of AEA, compared to healthy tissue. And in studies with mouse brain slices, they found that inducing damage with a brain-cell-exciting chemical, called NMDA, caused an invasion of the brain's immune cells, called microglia, and an increase in AEA levels.

Keyword: Drug Abuse; Glia
Link ID: 8358 - Posted: 01.04.2006

Researchers from the University of Chicago have uncovered an important mechanism used by the developing brain to pattern nerve connections in the part of the brain that interprets visual signals. In the process, they have provided the first experimental evidence for a decades-old model of how nerve cells establish distant connections in a way that can consistently relay spatial information. In the January 5, 2006, issue of the journal Nature, the researchers show that a gradient of a molecule known as Wnt3 counterbalances another force provided by the EphrinB1-EphB signaling system. The balance between these two signaling systems, they show, is necessary to establish the carefully controlled pattern of nerve connections required to convey spatial information in the correct order from the eye to the brain. "This is the first biological validation of a computational model developed in the early 1980s that suggested that two such forces would be necessary to guide axons as they establish the connections that relay spatial information from one part of the nervous system to another," said study author Yimin Zou, Ph.D., assistant professor of neurobiology at the University of Chicago.

Keyword: Development of the Brain; Vision
Link ID: 8357 - Posted: 01.04.2006