Researchers get first glimpse at disease-causing prions
The Associated Press Researchers have captured the first images of a type of human protein called prions, which pair up in a way that may lead to "mad cow" and other diseases. The proteins are molecules that scientists had thought normally exist alone. Pictures taken by Cleveland Clinic and Case Western Reserve University scientists show a pair of prions linked. Several research teams worldwide have been trying to figure out how normal, harmless prions change into the deadly mad cow variety, which destroys brain tissue, and how they accumulate in clumps. The prion-to-prion link, which the Cleveland researchers pictured, may be an intermediate step in the processes. Copyright © 2001 Nando Media

Keyword: Prions
Link ID: 526 - Posted: 10.20.2001

Intimidation tactics may have led to speech
James Randerson Men attempting to show off to their rivals in prehistoric times may have led to the evolution of speech. The human voice box or larynx was thought to be unique, but now researchers have found two species of deer with "dropped larynxes" similar to those of humans. For the deer at least, it's all about the advantages of having a deep voice. A newborn baby's larynx resembles that of other mammals. It pokes up into the nasal passage like a snorkel, so babies can drink and breathe at the same time. But at three months old, the larynx descends, opening up a cavity behind the tongue. Journal reference: Proceedings of the Royal Society B (vol 268, p 1669)

Keyword: Language; Evolution
Link ID: 524 - Posted: 10.20.2001

HELEN PEARSON
"It has a touch of science fiction," admit the scientists who have wired up the first conducting nerve chip. The electronic circuit, grown from silicon and nerve cells, brings brain-repair chips, advanced biosensors and biological computers a small step towards reality. Peter Fromherz and Gunther Zeck of the Max Planck Institute for Biochemistry in Munich placed snail nerve cells on a silicon chip, fencing them in place with microscopic plastic pegs. Neighbouring cells grew connections with each other and with the chip1.

Keyword: Miscellaneous
Link ID: 523 - Posted: 10.20.2001

Emory University researchers have demonstrated that several regions of the adult rat brain have the capacity to acquire new neurons following the introduction of a growth factor into the brain's lateral ventricle, located in the depths of the cerebral cortex. The study is the first to show the presence of numerous new neurons in certain regions of the brain where they previously have not been found, and suggests that the adult brain may be able to replace neurons lost due to injury or disease. The results were published in the September 1 issue of the Journal of Neuroscience. The research team, headed by Emory Professor of Cell Biology Marla Luskin, Ph.D., also included Emory cell biology fellow Viorica Pencea, M.D., Kimberly Bingaman, M.D. and Stanley Wiegand, Ph.D., of Regeneron Pharmaceuticals, Inc.

Keyword: Development of the Brain; Trophic Factors
Link ID: 520 - Posted: 10.20.2001

In-the-mouth electrodes give blind people a feel for vision
Peter Weiss
Blind since birth, Marie-Laure Martin had always thought that candle flames were big balls of fire. The 39-year-old woman couldn't see the flames themselves, but she could sense the candle's aura of heat. Last October, she saw a candle flame for the first time. She was stunned by how small it actually was and how it danced. There's a second marvel here: She saw it all with her tongue. The tongue, an organ of taste and touch, may seem like an unlikely substitute for the eyes. After all, it's usually hidden inside the mouth, insensitive to light, and not connected to optic nerves. However, a growing body of research indicates that the tongue may in fact be the second-best place on the body for receiving visual information from the world and transmitting it to the brain. From Science News, Vol. 160, No. 9, Sept. 1, 2001, p. 140. Copyright ©2001 Science Service. All rights reserved.

Keyword: Vision; Pain & Touch
Link ID: 519 - Posted: 10.20.2001

By Jennifer Huget, Special to The Washington Post
A funny thing happened to me on April 2, kind of a belated April Fool's joke: My neurologist told me I had multiple sclerosis. For weeks I had found myself fervently praying that I had Lyme disease, whose symptoms sometimes mimic those of MS. No such luck. An MRI scan, a spinal tap and blood tests, none of them individually conclusive, together pointed to the fact that my body had decided to start attacking itself. Apparently thinking they are doing the right thing, certain misguided cells have taken it upon themselves to destroy the fatty myelin sheath that coats the nerve cells in my brain, leaving scars that prevent the nerves from doing their jobs. Why, I wonder, couldn't they attack the fatty cells in my thighs instead? © 2001 The Washington Post Company

Keyword: Multiple Sclerosis
Link ID: 517 - Posted: 10.20.2001

Human Brains May Take Unique Turn
Bruce Bower Two neuroscientists have tapped into what may represent a fundamental difference in brain development between people and other mammals. If the findings hold up, they'll offer insight into how humans evolved an enlarged frontal cortex capable of supporting symbolic thought and language use, conclude Kresimir Letinic and Pasko Rakic of Yale University School of Medicine. Researchers have identified many commonalties in how brains of various animal species develop. In contrast, facets of brain growth unique to any one species, including humans, have been elusive. From Science News, Vol. 160, No. 9, Sept. 1, 2001, p. 132. Copyright ©2001 Science Service. All rights reserved.

Keyword: Evolution
Link ID: 515 - Posted: 10.20.2001

Families of autistic children sue vaccine makers
The Associated Press BOSTON - Two Massachusetts families are suing several vaccine makers, claiming the companies' use of a controversial preservative poisoned their children and caused their subsequent autism. In the lawsuit filed in Middlesex Superior Court, the families allege that the children "were poisoned with toxic mercury" in the preservative thimersol.

Keyword: Autism; Development of the Brain
Link ID: 514 - Posted: 10.20.2001

Genetic Mutation That Causes Episodic Paralysis Identified
Researchers have identified a new gene mutation that causes episodes of muscle weakness or paralysis, according to a study published in the September 2001 Annals of Neurology, the research journal of the American Neurological Association. The researchers suspect that this particular mutation is responsible for the paradox that some patients with the disease, called hypokalemic periodic paralysis, actually fare worse on carbonic anhydrase inhibitors, drugs that help most other patients. "If this hypothesis holds up, physicians may be able to use the presence of the mutation to identify patients who should avoid the standard therapy," said senior author Louis J. Ptacek, MD, a neurologist at the Howard Hughes Medical Institute at the University of Utah.

Keyword: Genes & Behavior
Link ID: 513 - Posted: 10.20.2001

Dementia patients aware of losing grasp suffer breakdowns most
People with dementia who are still aware enough to realize they are losing their ability to function are the patients in nursing homes who may be most likely to have dramatic emotional breakdowns and to lash out physically or verbally, researchers at the University of Rochester School of Nursing have found. Nurse researcher Nancy Watson, R.N., Ph.D., and her team found that patients who are in the middle of their decline are five times as likely to become intensely distressed than patients either in the early or late stages of dementia.

Keyword: Alzheimers; Emotions
Link ID: 510 - Posted: 10.20.2001

Nature Medicine, September 2001
Brain tumors, such as those that affect glial cells, are amongst the most lethal of all cancers. Oftentimes, before a cure or treatment for a disease can be developed, it is vital to understand the pathology underlying the disease. Now, scientists at New York Medical College have identified a mechanism by which gliomas spread rapidly through brain tissue and perhaps more importantly, drugs already exist that may be able to curb this spread. Maiken Nedergaard and colleagues have discovered that glioma tumor cells release the neurotransmitter glutamate, which carves a path of destruction through brain tissue allowing the tumor cells to advance. Compounds that block the release of glutamate, such as MK801, were able to slow the growth of tumors implanted in the brains of adult rats.

Keyword: Glia
Link ID: 509 - Posted: 10.20.2001

Researchers have identified a novel gene that is mutated in mice that develop spontaneous epileptic seizures in response to loud noises. The brain protein affected by the mutation is unlike any other known to cause epilepsy in mice or humans. In an article published in the August 30, 2001, issue of the journal Neuron, a research team led by Howard Hughes Medical Institute investigator Louis J. Ptacek at the University of Utah reported cloning and sequencing the gene that is responsible for an audiogenic form of reflex epilepsy in the Frings mouse strain. Although this mouse strain -- in which seizures can be triggered by a loud noise -- has been used in research for half a century, the genetic defect underlying the disorder had been unknown.

Keyword: Epilepsy
Link ID: 508 - Posted: 10.20.2001

Experiment provides new clues to the location of visual consciousness
A new test that measures what people see when viewing discordant images in the right and left eyes has produced important new clues about the location of some of the brain activity underlying visual consciousness. The procedure, described in the Aug. 30 issue of the journal Nature, depends on a phenomenon called binocular rivalry first described in 1838 by Sir Charles Wheatstone. Using a device that he invented, Wheatstone discovered that when people are presented with dissimilar images in each eye, they report seeing first one image and then the other with the two images alternating unpredictably. For an overview of research on binocular rivalry, including examples of the test patterns used in the Nature article, go to Prof. Blake's website: http://www.psy.vanderbilt.edu/faculty/blake/rivalry/waves.html

Keyword: Vision; Laterality
Link ID: 507 - Posted: 10.20.2001

Mayo To Test Alzheimer's Vaccine On Humans
Previous Tests Completed On Mice ROCHESTER, Minn. -- The Mayo Clinic will test an experimental Alzheimer's vaccine in humans as part of a nationwide study that might determine whether the body's immune system can be used to fight the disease. The vaccine uses antibodies to clear excess protein from between brain cells, combating one of the disease's hallmark traits. Researchers hope that the vaccine can stop the cascade of events that leads to the destruction of memory, loss of the ability to think, and dementia in more than 4 million Americans. Copyright 2001 by Channel 2000. The Associated Press contributed to this report. All rights reserved.

Keyword: Alzheimers
Link ID: 505 - Posted: 10.20.2001

By Matthew Tokson - A new lab technique that causes temporary brain damage in healthy test subjects may hold the key to a better understanding of stroke and other brain disorders. But some scientists question whether the study is worth the risk, conjecturing that test subjects could potentially suffer damaging side effects. Using the technique, researchers at Boston's Beth Israel Deaconess Medical Center are the first to mimic the damage caused by stroke by creating "virtual lesions" in normal brains, according to an article in this month's Nature Neuroscience. The scientists used a technique known as transcranial magnetic stimulation, or TMS, which uses electromagnetic energy to temporarily deactivate parts of the brain. Copyright © 2001 ABCNEWS Internet Ventures.

Keyword: Brain imaging
Link ID: 504 - Posted: 11.07.2001

By DANIEL Q. HANEY, Associated Press
BOSTON - Two widely used childhood vaccines were found to sporadically trigger seizures but do not appear to cause any long-term disabilities, such as epilepsy or retardation, according to the biggest study of the subject. The study looked at children who had received the DTP vaccine to prevent diphtheria, tetanus and pertussis and the MMR vaccine for measles, mumps and rubella. Both vaccines can cause fever, and fever in turn can lead to seizures. The possibility of seizures is one of a variety of concerns that prompt some parents to oppose routine vaccinations, even though health experts argue that the benefit of preventing common childhood illnesses far outweighs any possible hazards. Copyright © 2001 Nando Media

Keyword: Epilepsy; Autism
Link ID: 503 - Posted: 10.20.2001

Dope-smoking dads double the risk of cot death, a survey in California has revealed.
Brian Morgan
Hilary Klonoff-Cohen and Phung Lam-Kruglick at the University of California, San Diego, wanted to find out if drugs such as marijuana increase the risk of sudden infant death syndrome (SIDS). They interviewed the parents of 239 infants who had died of SIDS, comparing them with those of 239 healthy infants. They found that the risk doubled when fathers used cannabis, regardless of whether this was around conception, during pregnancy or after birth. But surprisingly, the study did not reveal any increase in risk with maternal use. More at: Archives of Pediatrics and Adolescent Medicine (vol 155, p765) © Copyright Reed Business Information Ltd.

Keyword: Drug Abuse; Development of the Brain
Link ID: 502 - Posted: 10.20.2001

Spine tissue discovery could help injury victims Tests show spinal cord can be regrown in rats Vanessa Lu HEALTH POLICY REPORTER Researchers at the University of Toronto have managed to re-grow damaged nerve cells in paralyzed rats by implanting a chemical-filled plastic tube that serves as a bridge between two ends of a severed spinal cord. The results, presented yesterday at the American Chemical Society's meeting in Chicago, increase hopes that the research might eventually lead to a treatment for patients with spinal cord injuries. ``There's no magic bullet. This is not the answer yet, but it does provide some promise,'' says U of T researcher Molly Shoichet, cautioning much more research needs to be done before human trials would even begin. ``But I would definitely say there's hope.'' Copyright 1996-2001. Toronto Star Newspapers Limited. All rights reserved.

Keyword: Regeneration
Link ID: 501 - Posted: 10.20.2001

CHICAGO --- Using positron emission tomography scans to measure brain activity in people eating chocolate, a team of U.S. and Canadian neuroscientists believe they have identified areas of the brain that may underlie addiction and eating disorders. Dana Small, assistant professor of neurology at Northwestern University Medical School, and colleagues found that individuals' ratings of the pleasantness of eating chocolate were associated with increased blood flow in areas of the brain, particularly in the orbital frontal cortex and midbrain, that are also activated by addictive drugs such as cocaine.

Keyword: Drug Abuse
Link ID: 500 - Posted: 10.20.2001

Study Finds Brain Reacts To Sex-Specific Chemicals
By Shankar Vedantam Washington Post Staff Writer Certain chemicals similar to the male and female sex hormones trigger distinctive brain activity when sniffed by the opposite gender, providing the strongest evidence yet for the existence of human "pheromones," scientists reported yesterday. Brain scans of two dozen volunteers in Sweden found that a part of the brain involved in regulating sexual behavior lit up when women were exposed to a substance similar to testosterone, while the same brain area in men lit up when they were exposed to a substance similar to estrogen. The research, which convincingly demonstrated that the effect of these chemicals on the brain is not because of their odor, will be of interest to romantics, pharmaceutical companies and savants of armpit chemistry. © 2001 The Washington Post Company

Keyword: Chemical Senses (Smell & Taste); Sexual Behavior
Link ID: 498 - Posted: 10.20.2001