by Kirsten C. Sadler Recent studies indicate that during apoptosis engulfing cells do not simply dispose of suicidal cells but actively participate in killing them. Even more striking is the observation that a small percentage of target cells may show some morphological signs of apoptosis but then apparently change their mind and return from the brink of death. Once a cell has received a death signal and makes the molecular decision to commit suicide, the killing is carried out in a stepwise fashion by, in most but not all cases, members of the Bcl-2 family, release of cytochrome c and other factors from the mitochondria and, in all cases, activation of the caspase family of proteases. Caspases dismantle the cell and also activate other proteases to aid in the execution. Once the deed is done, the dead cell's neighbors engulf the cell corpse. Some cells return from the brink of death. © Elsevier Science Limited 2000

Keyword: Apoptosis
Link ID: 1041 - Posted: 11.27.2001

(SAN DIEGO, Calif.) -- A new study coming out of UC Davis Medical Center and the Center for Neuroscience shows how estrogen can protect brain cells against various insults that cause the mental deterioration seen in many ailments, including Alzheimer's disease. The study is among those specifically highlighted at Society for Neuroscience meeting in San Diego on November 14. "We found, for the first time, that the hippocampus, a brain structure involved in memory, which shrinks in Alzheimer's disease patients, was larger in postmenopausal women who were taking estrogen replacement therapy than in either postmenopausal women who were not taking estrogen or a group of elderly men," says William Jagust, of the University of California in Davis. "Our results support the idea that estrogen replacement therapy protects brain cells and reduces the risk of developing Alzheimer's disease in postmenopausal women." In the study the researchers examined the brains of 59 postmenopausal women and 38 elderly men. Some of the subjects had mild memory problems but none met the criteria for a diagnosis of Alzheimer's disease. The brain imaging technique, magnetic resonance imaging (MRI), which provides a three-dimensional picture of the living brain, determined the size of each subject's hippocampus. The hippocampus was larger in the women taking estrogen than in the women not taking estrogen and the men.

Keyword: Hormones & Behavior; Alzheimers
Link ID: 1039 - Posted: 11.26.2001

Newts grow new legs, Hydra new heads. These remarkable creatures may hold clues for researchers developing human cellular therapies. But the connections are only now starting to be made. HELEN PEARSON Take one flatworm, chop into 279 pieces and leave for two weeks. Feed occasionally. The result: 279 perfect new worms. The ability of flatworms, or planarians, to regrow an entire body from a handful of cells seems almost miraculous. Salamanders, starfish, tentacle-waving polyps and zebrafish - many and varied are the organisms that can regenerate new heads, limbs, internal organs or other body parts if the originals are lost or damaged. Unfortunately, people cannot. But over the past few years, researchers studying regenerating creatures have begun to identify the genes, proteins and signalling pathways that underlie these organisms' abilities. This work indicates that the gulf between us and them is not so great. "We have the genes planarians use to regenerate their brain, muscle, their entire head," says Alejandro Sanchez Alvarado of the University of Utah in Salt Lake City. © Nature News Service / Macmillan Magazines Ltd 2001

Keyword: Regeneration
Link ID: 1038 - Posted: 11.26.2001

By Rachel Robertson Why would two Emory professors be showing sexually arousing pictures to subjects? For science, of course. Stephan Hamann and Kim Wallen, along with psychology graduate student Rebecca Herman, are collaborating on a project to study neural responses to visual sexual stimuli. In order to do this, they use Functional Magnetic Resonance Imaging (FMRI), a technique for measuring brain activation using an MRI scanner. This technique capitalizes on the fact that increased neural activity requires increased blood flow; changes in blood flow show up on the FMRI scans. Wallen, professor of psychology, brings to the project his knowledge of the neurobiology of nonhuman primates, especially the mechanisms involved in female sexual behavior. Wallen was interested in how that information can be brought to bear on what is known about humans.

Keyword: Sexual Behavior; Brain imaging
Link ID: 1037 - Posted: 11.26.2001

Learn how genetics could play a role in addiction By Eric Haseltine Over 2000 years ago, the Greek scholar Plutarch said "Drunks beget drunkards." Modern research shows that Plutarch knew what he was talking about. Children of substance abusers are up to 5 times more likely than offspring of "normal" parents to have problems with dependency or addiction sometime in their lives. Individuals prone to drug and alcohol addiction may be born with a paucity of receptors sensitive to the neurotransmitter dopamine in a part of the brain called the nucleus accumbens. Release of dopamine in this nucleus is believed to produce feelings of pleasure in response to normal healthy behaviors such as eating and procreating, but recent research suggests that substance abusers, born with too few dopamine receptors, cannot experience normal pleasures without taking chemicals that stimulate excess dopamine release. © Copyright 2001 The Walt Disney Company.

Keyword: Drug Abuse; Genes & Behavior
Link ID: 1036 - Posted: 06.24.2010

Name That Tone Can your child learn some of Mozart's magic? By Michael Abrams The psychology annex building at the University of California at San Diego has no elevator, but it has something even better: a singing stairwell. "It's a low F, I think," Diana Deutsch says, pausing on the top step to listen to the wind's howl. Deutsch has a face as round and sprightly as a sixteenth note, a red bob of hair, and a doctorate in psychology. She also has perfect pitch. "I realized I had it when I began taking piano lessons at the age of 4," she says. "It was a great surprise to me that other people could not name notes. It was as if everyone around me was unable to name colors." Mozart must have known how she feels: He could name a single note from a tolling bell or a chiming pocket watch. Yet only one in 10,000 Americans has perfect pitch, and even professional musicians tend to make do with relative pitch: They can name only the intervals between notes. To approximate perfect pitch, some musicians memorize just one note, usually middle C, and then use relative pitch to navigate to others. But these pitch estimators need a moment of thought to name a note, and they tend to be slightly off. (Granted, the notes themselves are a bit off: In Handel's time, an A above middle C had a pitch of 422.5 vibrations a second; these days, that same A has climbed to 440 vibrations a second.) People with perfect pitch name notes instantly and they're invariably correct. © Copyright 2001 The Walt Disney Company.

Keyword: Hearing
Link ID: 1035 - Posted: 11.25.2001

When it comes to evolution, survival of the fittest is only half the story. The handicap principle holds that humans make showy and sometimes dangerous displays of courage to increase their status and attract mates By Richard Conniff Two thirds of the way into his August 1998 attempt to fly round the world by balloon, Steve Fossett ran into a thunderstorm at 29,000 feet above the Coral Sea and began to plunge uncontrollably as wind and hail whipped his ruptured balloon. At 4,000 feet, he climbed through the hatch atop his capsule and cut away the fuel and oxygen tanks to slow the descent. Then he lay down on a bench to distribute the impending impact across his back. "I'm going to die," he said out loud. © Copyright 2001 The Walt Disney Company.

Keyword: Evolution; Sexual Behavior
Link ID: 1034 - Posted: 11.25.2001

By EDWARD WONG Corinne Spurrier was as enthusiastic as any soccer mom in Manhattan. On a crisp Saturday morning in Riverside Park, her 9-year-old son's team, the Golden Eagles, played their final game of the season on the banks of the Hudson River. She cheered as her son, Ian, raced across the grass in his yellow jersey. She clapped whenever one of his teammates scored and yelled when a player missed an opportunity. Only one thing nagged her: heading. When she saw Ian hit the ball with his head, a red light flashed on in her mind. "I should ask his pediatrician if this is a good thing for him to be doing," she said. "I think of Muhammad Ali. What are the side effects?" Copyright 2001 The New York Times Company

Keyword: Brain Injury/Concussion
Link ID: 1033 - Posted: 11.25.2001

Our behavior adapts to the daily environmental cycle; generally we sleep at night and are alert during the day. These adjustments to external circadian cycles are the consequence of subtle molecular changes inside our body which are ultimately regulated and determined at the genetic level. Researchers have known for some time that certain genes are turned on or off depending on the time of day. However, only some of the genes involved have been identified and they do not fully account for the mechanisms underlying perception and adaptation to daily cycles. Copyright © 1995-2001 UniSci. All rights reserved.

Keyword: Biological Rhythms; Genes & Behavior
Link ID: 1032 - Posted: 11.25.2001

Stanford, Calif. - A critical gene, osteopontin, which is involved in the development of multiple sclerosis, has been identified by researchers at Stanford University Medical Center and the University of California San Francisco. Osteopontin is already known to be a factor in the inflammatory immune response characteristic of MS, but now researchers believe it may be positioned at a number of checkpoints in the progression of the disease. The findings could lead to targeted new therapies for MS in the future. "The motivation for the study was the genomic application of Sutton's law," said Larry Steinman, MD, professor of neurology at Stanford. "Sutton's law" refers to a bank robber who, upon being asked why he robbed banks, answered, "Because that's where the money is." For Steinman and Jorge Oksenberg, PhD, associate professor of neurology at UCSF, the logic in examining autopsied brains from MS patients to learn about the disease is clear. "It's where the money is," said Steinman.

Keyword: Multiple Sclerosis
Link ID: 1031 - Posted: 11.25.2001

The bad news: patent leather shoes By Paul Greengard Monday, October 9, 2000 5:15 a.m.: Telephone rings. I grope in the dark for the receiver, which is off its base. I say to my wife, Ursula, "Who is the idiot calling at 5 a.m.?" Daughter, Ursie, in another bedroom, answers the phone before I find mine. As I pick up, I hear: "May I speak to Dr. Greengard?" Ursie: "It's the middle of the night. He is asleep. Do you really want me to wake him up?" "My name is Hans Jornvall. I am secretary of the Nobel Assembly." Me, quickly: "It's okay. I am awake. Don't hang up." "I am happy to inform you that the Nobel Assembly of the Karolinska Institute has awarded you this year's Nobel Prize in medicine for your research work on communication between nerve cells in the brain." "Oh, that's very nice. I am pleased to hear that." © 2001 The Washington Post Company

Keyword: Miscellaneous
Link ID: 1030 - Posted: 11.25.2001

Rare disorder offers insight Ursula Bellugi, the Salk Institute To some, perhaps the most striking distinction is the extraordinary connection that these people have with music. All exhibit a strong affinity for music, and while their attention span for many tasks is fleeting, they will spend hours listening to or making music. Research is scarce, but some evidence shows a high incidence of perfect pitch, and an uncanny sense of rhythm among this group.2,3 One boy with Williams syndrome was taught to tap a complicated 7/4-time rhythm with one hand while keeping 4/4-time with the other.4 Some researchers will not use the word "savant," but all admit that a connection with music exists, and that it and the other anomalies in this syndrome might help to further knowledge about disease and how the brain develops and works. The Scientist 15[23]:20, Nov. 26, 2001 © Copyright 2001, The Scientist, Inc. All rights reserved.

Keyword: Language; Genes & Behavior
Link ID: 1028 - Posted: 11.25.2001

Experimental Alzheimer's vaccines might work by generating antibodies that draw key brain proteins into the blood, rather than entering the brain themselves, new research suggests. The finding should lead to more effective Alzheimer's treatments in the future, the researchers say. One of the earliest changes in the brain of an Alzheimer's patient is the appearance of plaques of amyloid beta (a-beta) peptides. Elan Pharmaceuticals, based in Ireland, is currently testing an a-beta vaccine in Alzheimer's patients with moderate memory impairments. Previous research found that the vaccine cleared plaques in mice brains. Scientists thought that the vaccine worked by triggering the production of antibodies, which entered the brain and destroyed the plaques. But when a team led by David Holtzmann at Washington University, US, injected mice with anti-amyloid beta antibodies, they found the blood concentration of the peptides shot up. © Copyright Reed Business Information Ltd.

Keyword: Alzheimers
Link ID: 1027 - Posted: 11.23.2001

Vital new clues to what makes certain cells in the brain act as neural stem cells have been uncovered. The researchers say their work will boost research into creating new neurons to repair damaged brains. Recent experiments have provided strong evidence that in the developing fetal brain, a subsection of a group of cells called radial glial cells act as neural stem cells, giving rise to neurons. Related cells in the adult brain called astrocytes can also act as neural stem cells. But what gives certain radial glial cells and a very small number of astrocytes in two discrete adult brain areas their stem cell capabilities has been a mystery. © Copyright Reed Business Information Ltd.

Keyword: Stem Cells; Glia
Link ID: 1026 - Posted: 11.23.2001

Brain scans can reveal whether someone is lying or telling the truth, US researchers have discovered. When people lied, fMRI (functional magnetic resonance imaging) scans revealed significant increases in activity in several brain regions. Daniel Langleben and his colleagues at the University of Pennsylvania hope fMRI could be used for more accurate forensic lie detection. The widely used polygraph test is based on changes in heart rate, blood pressure, breathing and the electrical resistance of the skin. But these factors can vary widely among individuals, making it more difficult to establish whether someone really is telling the truth. Langleben's team gave 18 people an object to hide in their pockets. They were then shown a series of pictures, including one of the object itself. As each picture was presented, the participants were instructed to deny that it matched their hidden object. © Copyright Reed Business Information Ltd.

Keyword: Brain imaging
Link ID: 1025 - Posted: 11.23.2001

Early maternal neglect changes the expression of genes involved in the development of the dopamine system, research on mice has revealed. Abnormal regulation of dopamine in the brain has been linked to drug abuse, depression and personality disorders - conditions that are also associated with childhood neglect in humans. "Clearly, if the dopamine system of the brain is compromised, and if this can be extrapolated to humans, it could lead to greater susceptibility for drug dependence and perhaps greater vulnerability to develop certain psychiatric illnesses," says researcher Wayne Brake of the University of California, Santa Barbara. © Copyright Reed Business Information Ltd.

Keyword: Development of the Brain
Link ID: 1024 - Posted: 11.23.2001

Phantom limb pain can be prevented with a short course of a drug that blocks nerve over-activation, say German researchers. Seventy per cent of all people who undergo an amputation suffer from phantom limb pain, which can often be severe. For one week after amputation, most patients receive anaesthesia to block pain pathways from the remaining part of the limb. But while this may reduce levels of subsequent pain, it does not reduce the likelihood that some pain will occur, says Klaus Mathiak and his team at the University of Tübingen, Germany. Mathiak found that an additional course of a drug called memantine slashed the incidence of phantom limb pain at one year after amputation to 20 per cent. © Copyright Reed Business Information Ltd.

Keyword: Pain & Touch
Link ID: 1023 - Posted: 11.23.2001

PHILADELPHIA – Working with sleep-deprived fruit flies, scientists at the University of Pennsylvania have uncovered the first molecular pathway, in any species, implicated in the shift between rest and wakefulness. The findings, from a team led by Joan C. Hendricks of Penn's Center for Sleep and Respiratory Neurobiology, are reported in the November issue of the journal Nature Neuroscience. The work indicates that a Drosophila melanogaster gene known as CREB – evolutionarily conserved in species from flies to humans – plays a role in rest's rejuvenating effects, apparently permitting sustained wakefulness. Anyone who's ever pulled an all-nighter knows by the next morning that sleep is essential, and sleep's status as a behavior found in organisms ranging from fruit flies to frogs to humans underscores its importance as a biological process. But 50 years after the discovery of REM sleep, scientists still know little, on a molecular level, about why sleep is needed and the exact benefits conferred by a daily period of rest

Keyword: Biological Rhythms; Sleep
Link ID: 1022 - Posted: 06.24.2010

ANN ARBOR, Mich. - An international research team, led by University of Michigan Medical School scientists Marci Lesperance, M.D., and Margit Burmeister, Ph.D., has identified a gene responsible for an unusual type of hearing loss called low frequency sensorineural hearing loss. U-M researchers discovered that children who inherit one copy of the mutated gene called WFS1 gradually lose their ability to hear low-frequency sounds. The hearing loss becomes more severe over time, and eventually hearing aids are required. Patients with different types of mutations affecting both copies of the gene develop Wolfram Syndrome 1 - a rare, devastating condition involving juvenile diabetes, optic atrophy, and often deafness and psychiatric illness. The wider significance of this discovery is that mutations in this gene may be a common cause of low-frequency hearing loss in the general population, even in those who may be unaware that their hearing loss could be inherited. Results of the study appear in the October 22, 2001 issue of Human Molecular Genetics, published online Nov. 20 at the journal's web site: http://hmg.oupjournals.org/

Keyword: Hearing; Genes & Behavior
Link ID: 1021 - Posted: 11.22.2001

COLUMBUS, Ohio - Women who have had a major stressful event - death of a spouse, job loss, or a long-distance move - midway through their pregnancy may have a greater chance of having an autistic child than do their unstressed counterparts say researchers at The Ohio State University Medical Center. In a presentation at the annual meeting of the Society for Neuroscience in San Diego, Dr. David Beversdorf, a neurologist at OSU Medical Center and principal investigator of the study, reported on a study of 188 women who had delivered autistic children. The research showed that these women were more likely to have experienced a major stressor the 24th through 28th weeks of their pregnancy.

Keyword: Autism; Stress
Link ID: 1020 - Posted: 11.22.2001