Electric implants may ease Parkinson's by stimulating nerves. HELEN PEARSON Stimulating brain activity, not dulling it, might be the secret of a treatment for Parkinson's disease, say neuroscientists. The therapy may soon be used to treat psychiatric disorders. The technique, called deep brain stimulation, uses tiny buried electrodes to stimulate regions of the brain. How it works is obscure, doctors told the Society for Neuroscience meeting in Orlando, Florida. The mild current had been thought to stifle overactive regions that cause disease. But in some cases, it may boost nerves' activity and change their firing patterns, says Jerrold Vitek of Emory University, Atlanta, who works on a monkey version of Parkinson's. © Nature News Service / Macmillan Magazines Ltd 2002

Keyword: Parkinsons
Link ID: 2964 - Posted: 06.24.2010

Syracuse University researchers pick up where Darwin left off: Groundbreaking study to be published in the Nov. 8 issue of Science When it comes to mating and determining whose sperm reaches the elusive egg, females control both the playing field and the rules of the game, according to a new study on male sperm competition vs. female choice to be published in the Nov. 8 issue of Science. "Our study demonstrates, unambiguously, the active role females play in determining the conditions under which sperm compete inside the female reproductive tract," says Scott Pitnick, professor of biology at Syracuse University, who published the study with co-researcher Gary T. Miller, a postdoctoral research associate at SU. "It's widely known that, throughout the animal kingdom, sperm cells evolve rapidly into some of the most outrageous variations in size and shape. Until now, we didn't know why. Our study shows that it's because of female choice. The shape and physiology of the female reproductive tract is driving this variation in sperm." Most people are familiar with the elaborate competitions that occur between males before mating, such as the ritualistic clash of horns of Big Horn Sheep or the bloody battles between male elephant seals. However, relatively little is understood about how sperm compete after mating has occurred, says Pitnick, an evolutionary biologist who has been studying sexual selection and the nature of sex differences for more than 15 years. In a 1995 study published in Nature, he documented the longest sperm cell known to science. It belongs to a species of fruit fly called Drosophila bifurca and measures some two inches in length when fully uncoiled.

Keyword: Evolution; Sexual Behavior
Link ID: 2963 - Posted: 06.24.2010

DURHAM, N.C. -- Elderly adults who perform as well as younger adults on certain cognitive tests appear to enlist the otherwise underused left half of the prefrontal cortex of their brain in order to maintain performance, Duke University neuroscientists have found. In contrast, elderly people who are not "high performers" on the tests resemble younger adults in showing a preferred usage of the right side of the prefrontal cortex. The researchers said that, although their finding is basic, it raises the potential of using either training or drugs to enhance cognitive function in the elderly by increasing "recruitment" of the left prefrontal cortex. The evidence for compensatory brain activity in the high-performing elderly was reported in the November 1, 2002, issue of NeuroImage, by a research team led by Roberto Cabeza of Duke's Center for Cognitive Neuroscience. Other co-authors are Nicole Anderson, Jill Locantore and Anthony McIntosh of the University of Toronto.

Keyword: Alzheimers
Link ID: 2962 - Posted: 11.08.2002

Reuters WASHINGTON - Motherhood may make women smarter and may help prevent dementia in old age by bathing the brain in protective hormones, U.S. researchers reported on Thursday. Tests on rats show that those who raise two or more litters of pups do significantly better in tests of memory and skills than rats who have no babies, and their brains show changes that suggest they may be protected against diseases such as Alzheimer's. University of Richmond psychology professor Craig Kinsley believes his findings will translate into humans. Copyright 2002, azcentral.com. All rights reserved.

Keyword: Hormones & Behavior; Intelligence
Link ID: 2961 - Posted: 11.08.2002

PORTLAND, Ore. (AP) — A study showing a correlation between structural brain differences and sexual preferences in sheep supports an earlier human study that suggested orientation may be genetic. The study found that a cluster of cells in the preoptic hypothalamus, a region of the brain known to be involved in sexual behavior and partner preference, was larger in male-oriented rams than in female-oriented rams or in ewes. The research was led by Charles Roselli, a professor at Oregon Health & Science University, with help from scientists at Oregon State University and the U.S. Sheep Experiment Station in Dubois, Idaho. Copyright ©2002 WXIA-TV Atlanta

Keyword: Sexual Behavior
Link ID: 2960 - Posted: 06.24.2010

There is no link between the measles, mumps and rubella jab and autism, according to the latest research. The Danish study, which looked at over 530,000 children, reinforces previous findings that there is no link between the jab and the condition. It found the risk of autism was the same for children who had been vaccinated as those who had not. There was also no cluster of autism cases seem at any time after immunisation. And no kind of autistic disorder was linked to the MMR jab. Four years ago, Finnish scientists carried out a study based on 14 years worth of data, which ruled out a link between MMR and autism, or a chronic bowel inflammation. (C) BBC

Keyword: Autism
Link ID: 2959 - Posted: 11.07.2002

By Helen Briggs BBC News Online science reporter Having two X chromosomes may be protective against whatever predisposes someone to not being able to make sense of the social world. The key is the female X chromosome, which seems to protect against disorders linked with poor social interactions. Dr Ruth Campbell of University College London, UK, says there may be genes on the X chromosome that are important for the development of social skills. Men have only a single X chromosome. It is possible that the difficulties some experience in displaying appropriate social behaviour could be down to this, she says. "Having two X chromosomes may be protective against whatever predisposes someone to not being able to make sense of the social world," she told BBC News Online. (C) BBC

Keyword: Genes & Behavior
Link ID: 2958 - Posted: 11.07.2002

Exclusive from New Scientist Print Edition Ecstasy is being hailed as the key to better treatments for the Parkinson's disease, marking a complete turnaround from a few weeks ago when ecstasy was condemned for causing the disease. New animal studies have confirmed anecdotal reports that ecstasy can dramatically curb the uncontrollable arm and leg movements that plague so many people with Parkinson's. But the finding may be of little immediate help to sufferers. The researchers are not calling for patients to be given legal supplies of ecstasy (MDMA). Instead, they want to look for related drugs with the same beneficial effects. And patients are being warned against trying MDMA for themselves. "It's impure, illegal and dangerous," says Robert Meadowcroft, policy director of Britain's Parkinson's Disease Society. © Copyright Reed Business Information Ltd.

Keyword: Drug Abuse; Prions
Link ID: 2957 - Posted: 06.24.2010

by Robert A. Sweet, M.D. Psychiatric Times November 2002 Vol. XIX Issue 11 Psychotic symptoms, namely hallucinations and delusions, are common in individuals with Alzheimer's disease (AD). This article will examine the proposal that Alzheimer's disease with psychosis (AD+P) has an underlying genetic and neurobiologic basis distinct from that of AD without psychosis. Most estimates of the prevalence of psychosis in patients with AD range from 30% to 40% (Wragg and Jeste, 1989). Rates in community samples are similar (Lyketsos et al., 2000). The presence of psychotic symptoms can cause significant distress for the patient, as well as for family members and caregivers (Kaufer et al., 1998). Subjects with AD+P are also prone to aggressive behavior, further contributing to caregiver burden (Aarsland et al., 1996; Deutsch et al., 1991; Sweet et al., 2001b). In addition to disruptive behavior, AD+P has been associated with more severe cognitive and functional deficits compared to patients who have AD without psychosis who are matched on other clinical characteristics (Jeste et al., 1992; Paulsen et al., 2000a; Stern et al., 1987). Alzheimer's disease with psychosis is also associated with more rapid cognitive and functional deterioration (Drevets and Rubin, 1989; Levy et al., 1996; Paulsen et al., 2000b). © 2002 Psychiatric Times. All rights reserved.

Keyword: Alzheimers
Link ID: 2956 - Posted: 06.24.2010

By NICHOLAS WADE Dr. Tatiana's Sex Advice to All Creation," by Dr. Olivia Judson, Metropolitan Books, $24. "Dear Dr. Tatiana, My name's Twiggy, and I'm a stick insect. It's with great embarrassment that I write to you while copulating, but my mate and I have been copulating for 10 weeks already. I'm bored out of my skull, yet he shows no sign of flagging. . . . How can I get him to quit? Sick of Sex in India." Dr. Tatiana is the pen name of Dr. Judson, an evolutionary biologist who has discovered that an advice columnist's pose is a deft device for discussing the mating game's many amazing variations in nature. Copyright The New York Times Company

Keyword: Evolution; Sexual Behavior
Link ID: 2955 - Posted: 11.07.2002

Day 3: Tuesday Nov 5th, 2002
Preventing a shaky future for Parkinson's patients Investigators: Anders Björklund and Gary Housley Anders Björklund of Lund University in Sweden, a leader in fetal tissue transplantation, issued a clarion call to his fellow scientists by mapping out future research priorities. Experimental cell transplants have helped hundreds of Parkinson's patients, but challenges remain in basic research.
A whole new view of the Parkinson's problem Investigators: Jonathan Dostrovsky and Jerrold Vitek The real culprit behind the motor symptoms of Parkinson's may be the irregular pattern - and not the rapid rate - of neuronal firing, mounting new evidence suggests.
New evidence of aggregate toxicity in Huntington's Disease Investigators: Wen Yang and Ronald Wetzel A new assay provides "the best in vitro evidence" that polyglutamine protein aggregates are toxic in Huntington's disease, according to a study presented today at SFN.
Markers for memory decline Investigator: Michela Gallagher Memory makes us who we are. However, scientists are finding that memory loss associated with aging isn't what they once thought it was. In healthy elderly animals, subtle functional changes in the neurons seem to be correlated with memory impairment.
Brain cancer infiltrates SFN Investigators: Luis Parada, Terry Van Dyke, William Weiss and Thomas Curran Today, for the first time ever, brain cancer made a scheduled appearance at the annual meeting of Society for Neuroscience. Researchers say the time is right to join the fields and break down the barriers that have slowed progress in the disciplines.

Keyword: Miscellaneous
Link ID: 2954 - Posted: 06.24.2010

Researchers funded by the National Institute of Mental Health (NIMH) have discovered a high tech way to quell panic in rats. They have detected the brain's equivalent of an "all clear" signal, that, when simulated, turns off fear. The discovery could lead to non-drug, physiological treatments for runaway fear responses seen in anxiety disorders. Rats normally freeze with fear when they hear a tone they have been conditioned to associate with an electric shock. Dr. Gregory Quirk and Mohammed Milad, Ponce School of Medicine, Puerto Rico, have now demonstrated that stimulating a site in the front part of the brain, the prefrontal cortex, extinguishes this fear response by mimicking the brain's own "safety signal." They report on their findings in the November 7, 2002 Nature. "Repeated exposure to traumatic reminders without any adverse consequences causes fear responses to gradually disappear," explained Quirk. "Such reduction of fear appears to be an active rather than passive process. It doesn't erase the fear association from memory, but generates a new memory for safety."

Keyword: Emotions; Stress
Link ID: 2953 - Posted: 11.07.2002

Researchers studying the Hedgehog signaling pathway have identified small molecules that could form the foundations of exciting new treatments for Parkinson's disease and certain cancers. New research published in Journal of Biology - the open access journal for exceptional research - has identified small molecules that are able to stimulate or block the Hedgehog signalling pathway, which is essential to the development, maintenance and repair of cells in the human body. The potential of these molecules to be used as drugs to treat both degenerative diseases and cancer is exciting as their small size may allow these molecules to enter all parts of the body and cross the blood brain barrier, eliminating the need for injections of therapeutics directly into the target site. The Hedgehog signaling pathway is crucial to the development of healthy animals as well as the maintenance and repair of adult cells. Hedgehog genes were first identified in the fruitfly, and were so called because fly embryos with a defect in this gene were covered in bristles. The central role of the Hedgehog signalling pathway in the regulation of the growth and division of specific types of cells makes it of great interest to researchers investigating diseases like Parkinson's that are characterised by a lack of particular cells as the central nervous system degenerates.

Keyword: Parkinsons; Genes & Behavior
Link ID: 2952 - Posted: 11.07.2002

Rehovot, Israel---How do 30,000 genes in our DNA work together to form a large part of who we are? How do one hundred billion neurons operate in our brain? The huge number of factors involved makes such complex networks hard to crack. Now, a study published in the October 25 issue of Science uncovers a strategy for finding the organizing principles of virtually any network – from neural networks to ecological food webs or the Internet. A team headed by Dr. Uri Alon, of the Weizmann Institute of Science's Molecular Cell Biology Department has found several such organizational patterns – which they call "network motifs" – underlying genetic, neural, technological, and food networks. The mathematical technique was first proposed by Alon earlier this year (published in Nature Genetics) and has now been shown to be applicable in a wide range of systems. In developing the technique, Alon surmised that patterns serving an important function in nature might recur more often than in randomized networks. This in mind, he devised an algorithm that enabled him to analyze the plentiful scientific findings examining key networks in some well-researched organisms. Alon noticed that some patterns in the networks were inexplicably more repetitive than they would be in randomized networks. This handful of patterns was singled out as a potential bundle of network motifs.

Keyword: Genes & Behavior
Link ID: 2951 - Posted: 06.24.2010

ITHACA, N.Y. -- Virtually hairless, venerably wrinkled and very nearly blind, naked mole-rats -- those homely rodents from underground Africa -- remind some zoo-goers of little old men. The resemblance is more than coincidence. They really are really old males -- and females, too -- biologists report in an article scheduled for November publication in the Journal of Zoology (Vol. 258, Part 3). Many naked mole-rats (Heterocephalis glaber ) in laboratory colonies in the United States and South Africa have lived more than 20 years, and some are at least 26 years old, making them by far the oldest small rodents in captivity. That distinction won't get them birthday greetings from the president. But their species is being hailed as a perfect exemplar for the evolutionary theory of senescence (or aging), which explains why some bodies wear out before others. Senescence theory also tries to explain, for example, why gerbils live only a couple of years, humans regularly live eight to nine decades and redwood trees for millennia.

Keyword: Evolution; Development of the Brain
Link ID: 2950 - Posted: 11.07.2002

Heart drugs soothe brain inflammation. HELEN PEARSON Widely used cholesterol-lowering drugs could relieve multiple sclerosis, say researchers. The drugs might also work on other diseases where the immune system attacks the body. The drugs, called statins, are commonly prescribed to fight heart disease. The new study shows that they may also work on the immune system, reducing brain inflammation. Multiple sclerosis is thought to arise when the immune system assaults the nervous system. It strikes with unpredictable symptoms including fatigue, tremor and paralysis. Existing treatments can slow, but not stop, the advance of the disease. © Nature News Service / Macmillan Magazines Ltd 2002

Keyword: Multiple Sclerosis
Link ID: 2949 - Posted: 06.24.2010

Neuroscientists challenge tenets of intelligence testing. HELEN PEARSON Many people underscore on IQ tests because the benchmark memory test is inaccurate, a US researcher told the Society for Neuroscience meeting in Orlando, Florida yesterday. Another announced that women's brain size could affect IQ. In standard intelligence tests, subjects are asked to remember a string of random numbers. The widely quoted average before stumbling - seven, give or take two - is thought to reveal the capacity of our short-term memory. This 'magic number' is a huge overestimate, claims Mrim Boutla of the University of Rochester in New York. She puts the real size of short-term memory at four digits, plus or minus one - so too do several other studies challenging the gold standard. © Nature News Service / Macmillan Magazines Ltd 2002

Keyword: Learning & Memory; Intelligence
Link ID: 2948 - Posted: 06.24.2010

Functional magnetic resonance imaging (fMRI) studies of the brain show that despite the decrease in brain activity that naturally occurs in aging, particularly in the language areas of the left frontal lobe, some types of language processing may be performed more efficiently in older individuals. Results of these experiments, performed by Darren Gitelman, M.D., and colleagues at the Cognitive Neurology and Alzheimer's Disease Center at Northwestern University, stand in contrast to performance and brain imaging findings in other areas of brain function, such as memory, attention and response speed, where older persons show decreased performance and efficiency when compared with younger populations. The findings, which Gitelman and his co-investigators presented at today's Society for Neuroscience meeting in Orlando, Fla., are consistent with theories that suggest that some brain functions may be preserved with age.

Keyword: Language; Alzheimers
Link ID: 2947 - Posted: 11.07.2002

By SANDRA BLAKESLEE Neuroscientists have found an evocative solution to a classic problem: which is more important in shaping the human brain, nature or nurture? Their answer is complex. The brain is not primarily the product of genes, they say, but neither is it simply the sum of one's experiences. Rather, they say, each human brain is constructed of complex neural circuits that start taking shape before birth and continue to grow and change throughout life as genes and cells are influenced by environment, experience and culture. There is widespread agreement that genes and environment interact in brain development, said Dr. Terrence J. Sejnowski, a neuroscientist at the Salk Institute in San Diego, and a leading proponent of the new synthesis. The new idea, he said, is that human cultures, which teach children what to believe and what to expect in life, interact with cell biology and molecular genetics to assemble the highly social human brain. Copyright The New York Times Company

Keyword: Development of the Brain; Genes & Behavior
Link ID: 2946 - Posted: 11.06.2002

By DENISE GRADY At 6:30 in the morning, a strapping teenager on the cusp of manhood can look an awful lot like a newborn puppy, with eyes that won't open and a powerful instinct to curl up under something warm. Is this the same person who swore he wasn't tired at 10:30 the night before while he traded instant messages with six different friends at once, and who will probably do it again tonight? Parents know the adolescent drill all too well: stay up past 11 or 12 on school nights, stagger out of bed at 6 or 7, shower interminably, eat a token breakfast and bolt. Yawn through school, perk up for sports or clubs, fight sleep while doing homework. Come to life at 9 p.m., deny fatigue and stay up well after parents have collapsed into bed. Holidays and weekends, stay up half the night and then "binge sleep" until noon or beyond. Sunday night, restart the cycle of late to bed and early to rise. Copyright The New York Times Company

Keyword: Development of the Brain; Sleep
Link ID: 2945 - Posted: 11.06.2002