Scientists at Johns Hopkins have discovered the first direct evidence in mammals that a chemical intermediate in the production of fatty acids is a key regulator of appetite, according to a report in a recent issue of the Proceedings of the National Academy of Sciences. Scientists have long known that hunger causes increases in some brain chemicals while lowering others. However, the root cause of hunger's effects -- the initial chemical trigger of appetite -- has been elusive. In experiments with mice, the Johns Hopkins researchers showed that appetite is immediately and directly tied to amounts of a chemical called malonyl-CoA. In hungry mice, malonyl-CoA was almost undetectable in the brain. Once fasting mice were given food, however, amounts of the chemical increased to high levels within two hours. Furthermore, chemically reducing appetite by injecting a compound called C75 into the brain brought levels of malonyl-CoA up to those of mice given food, helping to explain C75's effects.

Keyword: Obesity
Link ID: 4718 - Posted: 12.19.2003

Singing fish sometimes let meek males join a menage a trois David Perlman, Chronicle Science Editor Most Sausalito residents know the humming toadfish, whose loud and incessant underwater droning all summer long keeps angry shore dwellers and houseboat residents awake for nights. The sound -- a perfect A-flat -- was a mystery for years, blamed by some conspiracy theorists in the 1980s on secret experiments by the Army Corps of Engineers lab on the city's waterfront, on the local water treatment plant or even on extraterrestrials. Then, a San Francisco marine biologist recognized it as the annoying sound that he'd heard as a graduate student studying fish and trying to sleep on the beach in Baja California: It was the sex call of a species known as the plainfin midshipman. ©2003 San Francisco Chronicle | Feedback | FAQ

Keyword: Sexual Behavior; Animal Communication
Link ID: 4717 - Posted: 06.24.2010

NewScientist.com news service A British man has died from variant CJD after receiving a blood transfusion seven years earlier from a donor who also later died from the disease. The UK secretary of state for health announced the case in an emergency statement to parliament on Wednesday. The case may be the first in the world where the human form of BSE - mad cow disease - has been transmitted via a blood transfusion. But John Reid told the House of Commons: "This is a possibility not a proven causal connection." Both individuals might have acquired the devastating illness separately by eating BSE-infected meat, he says, but "the possibility of this being transfusion-related cannot be discounted". © Copyright Reed Business Information Ltd.

Keyword: Prions
Link ID: 4716 - Posted: 06.24.2010

By Larry O'Hanlon, Discovery News — The bills and brains of duck-billed platypuses are specially equipped with electro-sensors to home in on the electrical signals of prey in muddy night-time stream bottoms, say Australian biologists. A row of nerves in platypus bills, wired to the touch and electro-sensing part of the platypus brain, work like a short-range radar system to pick up the electrical signals of fish, shrimp, crayfish and other invisible food in the murky platypus feeding grounds. The sensory system is just one more remarkable asset for the egg-laying, aquatic Australian mammal. Copyright © 2003 Discovery Communications Inc.

Keyword: Pain & Touch
Link ID: 4715 - Posted: 06.24.2010

Carvings show early Europeans' prodigious skill. MICHAEL HOPKIN A set of ivory figurines found in southwestern Germany add to a growing cache of the oldest art known. The 30,000-year-old carvings underline the remarkable creativity of our earliest European ancestors. Nicholas Conard of the University of Tübingen, Germany, discovered the 2-centimetre-high figures in the Hohle Fels Cave in the country's Swabia region1. The figurines, and similar relics previously unearthed in Swabia, are the earliest known representations of living forms. "Without question, they are the oldest corpus of figurative art in the world," says archaeologist Anthony Sinclair of the University of Liverpool, UK. © Nature News Service / Macmillan Magazines Ltd 2003

Keyword: Evolution
Link ID: 4714 - Posted: 06.24.2010

Stroke experts have issued a warning about the dangers of binge drinking linked to the Christmas party season. The Stroke Association says women are particularly at risk if they drink large amounts of alcohol. Men who drink more than five units of alcohol - half a bottle of wine or two and a half pints of beer - have double the normal stroke risk. The Stroke Association's Margaret Goose said: "By getting too 'merry' people are risking their lives." Small amounts of alcohol - one or two units a day - actually appear to reduce the risk of stroke caused by blood clots blocking the arteries supplying the brain - the cause of the majority of strokes. However, even small amounts of alcohol may increase the smaller risk of a stroke caused by a rupture of a blood vessel. (C) BBC

Keyword: Stroke; Drug Abuse
Link ID: 4713 - Posted: 12.17.2003

By DAVID F. MUSTO In the 1860's a new drug-delivery system, the hypodermic syringe, was perfected. An injection of a small amount of morphine was found to produce the same effect as a larger dose by mouth. Physicians assumed, therefore, that hypodermic injections offered more protection against addiction. Patients with chronic but not life-threatening pain, say osteoarthritis, were provided with morphine and a syringe and told to inject themselves when there was pain. It took some years to appreciate the mistake, but the sad outcome was that the hypodermic syringe not only did not protect from addiction, but it also facilitated it. By 1920 the president of the American Medical Association, Dr. Alexander Lambert of Cornell, somberly stated that "nearly 80 percent of the morphine addicts have acquired the habit from legitimate medication" provided by physicians. During the 1920's the fear of prescribing addictive medicine permeated American medical practice. Pain medication had to be doled out with great care and parsimony. Inadequate pain relief characterized the life of some cancer sufferers as well as postoperative patients. In the 1960's a movement to bring adequate pain relief attracted both researchers and practitioners. Copyright 2003 The New York Times Company

Keyword: Pain & Touch; Drug Abuse
Link ID: 4712 - Posted: 12.17.2003

We humans are proud of our big noggins. The average human skull, which packs some 1350 cubic centimeters (cc) of brainpower, is larger than that of any other animal, relative to body size. Now a molecular biologist suggests that a recently identified gene called ASPM might be implicated in the impressive expansion hominid brains have undergone over the last 2 million years. The work builds on studies of a rare disease called autosomal recessive primary microcephaly (MCPH). In this inherited malady, the brain is typically just 400 cc--roughly the same size as that of the early hominid Australopithecus africanus, of which "Lucy" is the best-known specimen. A earlier report concluded that the most common cause is a mutated ASPM gene (ScienceNOW, 23 September 2002). Jianzhi Zhang of the University of Michigan, Ann Arbor, hypothesized that ASPM might have played a key role in human brain expansion. To test this hypothesis, he looked for evidence that the gene was under "positive selection," meaning that it had provided an evolutionary advantage to hominids. Zhang compared the DNA nucleotide sequence of the human version of ASPM to that of two of our great ape cousins, the chimpanzee and the orangutan, as well to more distantly related animals such as rhesus monkeys, seals, dogs, and hamsters. A gene is considered to have undergone positive selection when it has a relatively high ratio of nucleotide changes that lead to a change in the amino acid sequence of the corresponding protein, compared to changes that make no difference. This ratio was quite high in humans but much lower in chimpanzees and orangutans, Zhang reports in the December issue of Genetics. Copyright © 2003 by the American Association for the Advancement of Science.

Keyword: Genes & Behavior; Evolution
Link ID: 4711 - Posted: 06.24.2010

How you react to stress influences how easily you resist or succumb to disease, including viruses like HIV, discovered UCLA AIDS Institute scientists. Reported in the Dec.15 edition of Biological Psychiatry, the new findings identify the immune mechanism that makes shy people more susceptible to infection than outgoing people. "Since ancient Greece, physicians have noticed that persons with a 'melancholic temperament' are more vulnerable to viral infections," said Steve Cole, principal investigator and assistant professor of hematology-oncology at the David Geffen School of Medicine and a member of the UCLA AIDS Institute. "During the AIDS epidemic, researchers found that introverted people got sick and died sooner than extroverted people," said Bruce Naliboff, co-author and a clinical professor at the UCLA Neuropsychiatric Institute and Veterans Affairs Greater Los Angeles Healthcare System. "Our study pinpoints the biological mechanism that connects personality and disease."

Keyword: Neuroimmunology
Link ID: 4710 - Posted: 12.17.2003

By Ellen Barry, Globe Staff, The way Ernest Hemingway had a drinking problem and Fyodor Dostoevsky had a gambling problem, Dr. Alice Flaherty, a Harvard neurologist, had a writing problem. During a severe bout of postpartum depression three years ago, she wrote so compulsively that the sight of a blank computer screen gave her a narcotic rush. Worried about damaging her family, Flaherty started taking a psychiatric drug to calm her mood swings -- and found that, although ideas still churned in her brain, she was no longer able to put them on paper. It was an excruciating case of writer's block. Thus begins her exploration of "hypergraphia" -- a term used by doctors to describe the overwhelming desire to write -- and its agonizing opposite. In her new book, "The Midnight Disease: The Drive to Write, Writer's Block and the Creative Brain," Flaherty lays out all that neurology has discovered about the artist's brain, from the strange profusion of literary giants with temporal lobe epilepsy to the composer Dmitry Shostakovich's certainty that musical notes radiated from a piece of shrapnel lodged in his brain. The drive to create, Flaherty concludes, is not the same thing as literary talent -- and doctors sometimes ignore it when they are prescribing medications. For her part, Flaherty chose to protect her drive, abnormal though it may be. As she finished the last page of her manuscript, she noted that it was 5:30 a.m., and she had been writing for so long that her legs had become numb. © Copyright 2003 Globe Newspaper Company.

Keyword: Miscellaneous
Link ID: 4709 - Posted: 06.24.2010

Study: Researchers say a communication system high in the nose increases the contrast in odors. By Jonathan Bor, Sun Staff When molecules of freshly ground coffee waft into your nose through a kitchen full of aromas, what makes you notice the coffee? And what, to the trained nose, suggests gourmet rather than canned, espresso rather than regular? Though the complete answer might be years off, smell researchers at the University of Maryland School of Medicine say they've found an important clue: a communications system high in the nose that heightens the contrast between odors so the brain can make better sense of them. Nerve bundles that capture particular scents relay their information to the brain, but not before negotiating with each other to decide what odors should be turned up and down, they said. The system evolved not simply to enhance our appreciation of aromas but, on the most basic level, to help animals survive in the wild. Copyright © 2003, The Baltimore Sun | Get home delivery

Keyword: Chemical Senses (Smell & Taste)
Link ID: 4708 - Posted: 06.24.2010

By REBECCA M. MILZOFF, Crimson Staff Writer The zebrafish looks like any other run of the mill aquarium-inhabitant—a small, glittery swimmer suited to the fishbowl world of a childhood pet. But to Gund Professor of Neuroscience John E. Dowling, this fish represents a living window into the complex interactions between vision and the brain. As Dowling and his laboratory researchers have discovered, study of retinal activity and development in zebrafish provides clues to the connection between what we see and how we act. “I’ve long been interested in the visual system,” Dowling says. He has always used the retina as a model for research in the brain, in part due to the variety of cells involved in retinal actions. Aside from photoreceptors, five other types of neurons in the retina connect with the brain to help start the process of visual imaging. Copyright © 2003, The Harvard Crimson Inc.

Keyword: Vision
Link ID: 4707 - Posted: 06.24.2010

A drug used to treat skin infections including Athlete's Foot could help to slow the progression of Alzheimer's disease, scientists say. A team at University College London said tests of Clioquinol on 36 patients were "encouraging". Their disease was shown to develop less quickly than those given a dummy pill. A second study in the journal Archives of Neurology found stroke patients are at an increased risk of developing Alzheimer's. In Alzheimer's disease, protein deposits called amyloid plaques form which impede and kill nerves in the brain. The plaques need zinc for the proteins to clump together. Clioquinol, which has antibacterial and antifungal properties, is used as an ointment to treat skin infections, but it also binds metal atoms. (C) BBC

Keyword: Alzheimers
Link ID: 4706 - Posted: 12.16.2003

by Maria A. Oquendo, M.D. Psychiatric Times Patients suffering from depressive disorders, particularly those with a history of suicide attempt, are at increased risk for future suicidal acts. Neurobiological studies of suicidal behavior have investigated anomalies that distinguish suicide attempters and completers from individuals who are depressed but do not engage in any suicidal behavior. To aid in the development of a predictive model in which both biological measures and clinical instruments are used to identify those at risk for future suicidal acts, studies have focused on biological correlates of behavioral and other factors identified by clinical studies as indicative of higher risk for suicidal behavior, such as aggression/impulsivity. Neuroendocrine challenge and cerebrospinal fluid (CSF) studies suggest that suicide attempters have decreased function in the serotonin system (Malone et al., 1996; Siever et al., 1984; Virkkunen et al., 1989). Among individuals with depression, high-lethality suicide attempts are associated with even lower serotonergic function (Malone et al., 1996; Mann and Malone, 1997). Neuroendocrine challenges and CSF measures are, however, unable to provide specific information about the anatomical location of abnormality. So far, it is known from studies mapping postmortem serotonin receptor binding that cortical serotonergic abnormalities associated with suicide are localized to the ventral prefrontal cortex (PFC) region of the brain (Arango et al., 1997). Positron emission tomography (PET) studies offer a distinct advantage over previous methodologies, allowing for more precise in vivo identification and study of the activity of brain regions that differ in those who have survived a suicide attempt of high lethality, compared to those surviving a low-lethality attempt. Given the findings of CSF and neuroendocrine studies with respect to differences in serotonin levels between high- and low-lethality attempters, PET studies of high-lethality attempters would be expected to reveal pronounced differences. © 2003 Psychiatric Times. All rights reserved.

Keyword: Depression
Link ID: 4705 - Posted: 06.24.2010

By Rossella Lorenzi, Discovery News — Unfaithful male salamanders returning home might find their female partners waiting with rolling pins, new research reveals. In a study slated for publication in the journal Animal Behavior, behavioral ecologist Ethan Prosen of the University of Louisiana in Lafayette shows that red-backed female salamanders (Plethodon cinereus) sexually intimidate their Casanova partners by punishing them with bites and aggressive postures. "We do not know of any other animals where the females use this coercion and the males also use coercion," Prosen told Discovery News. Copyright © 2003 Discovery Communications Inc.

Keyword: Sexual Behavior
Link ID: 4704 - Posted: 06.24.2010

By RICHARD A. FRIEDMAN, M.D. Everyone knows the holiday season can be hazardous to one's health. Just think of the warnings already abundant in the news media, alerting to the perils of gluttony and excess, not to mention overshopping. Even the fitness clubs are gearing up for their post-holiday campaign, in time to capitalize on the ill effects of guilty pleasure. And just when you thought you had all bases covered, up rises the threat of the holiday blues. We are, it seems, to be mentally as well as physically challenged from Christmas to New Year's. Conventional wisdom has it that the season of joy and cheer is really a harbinger of serious depression for some and a general downer and a disappointment for many. Is it really all that bad? Judging from the Internet, one would think that an epidemic was under way. Typing "holiday blues" in Google yielded nearly two million hits. A quick look at the first 100 or so showed a variation on two themes, how to diagnose the disorder and how to chase it away with a medley of nostrums. Copyright 2003 The New York Times Company

Keyword: Depression
Link ID: 4703 - Posted: 12.16.2003

By ANAHAD O'CONNOR and DENISE GRADY The Food and Drug Administration effectively approved the use of an obesity drug, Xenical, for adolescents yesterday. This is the first time that a weight-loss drug has been permitted to treat overweight children. A spokeswoman for the drug agency said it had decided to allow the manufacturer to add to the Xenical labels two studies that involved children to help doctors prescribe the correct doses for 12- to 16-year-olds. Terence Hurley, a spokesman for Hoffman-La Roche, the manufacturer, said it had no plans to market the drug for teenagers, but added that it was good news for children who battle obesity. Copyright 2003 The New York Times Company

Keyword: Obesity
Link ID: 4702 - Posted: 12.16.2003

By ERICA GOODE Many American psychiatrists were taken by surprise last week when British drug regulators told doctors to stop writing prescriptions for all but one of a newer generation of antidepressant drugs to treat depressed children under 18. Now the psychiatrists are trying to figure out how to advise the parents of the young patients who come to them for help. Some parents, the doctors say, are calling to ask if the drugs their children are taking are really safe. "The news has certainly generated anxiety, concern and questions," said Dr. Flemming Graae, the chief of child and adolescent psychiatry at Westchester Medical Center in Valhalla, N.Y. Copyright 2003 The New York Times Company

Keyword: Depression; Development of the Brain
Link ID: 4701 - Posted: 12.16.2003

Columbus, Ohio – A tiny difference in a gene may signal that a person is twice as susceptible to multiple sclerosis (MS) as normal. It could also foretell of a more rapidly progressing form of the disease, according to new research at The Ohio State University College of Medicine and Public Health. The study focused on a gene known as CD24, which directs the making of a protein found on immune cells and that plays an important role in immune responses. Specifically, the study looked at two different versions of the CD24 gene. The two versions differ because of a minute difference known as a single nucleotide polymorphism, or SNP (pronounced ‘snip’). A SNP is a difference of one so-called base, or nucleotide, in the gene’s DNA compared to the same gene in another person. SNPs are common and occur naturally. They may help give a unique pattern to each person’s DNA.

Keyword: Multiple Sclerosis
Link ID: 4700 - Posted: 06.24.2010

A study published in the December issue of Archives of Neurology and currently available online shows that levetiracetam reduced phasic spasticity, which is marked by spasms and painful muscle cramps, in 100 percent of patients in a small clinical study. "It's amazing how many MS patients can't walk, can't move, and you treat their spasticity and they're fine," said Dr. Kathleen Hawker, assistant professor of neurology at UT Southwestern and lead author of the study. "What's nice about these drugs is that they also work for nerve pain, which in turn improves the patient's mood, so we can use one drug for three things instead of prescribing pain killers and antidepressants in addition to the spasticity therapies." Spasticity is often seen in patients with MS and amyotrophic lateral sclerosis (ALS), as well as after a stroke or spinal-cord injury. It can lead to loss of balance, increased risk of falls, pain, fatigue, and walking difficulties.

Keyword: Multiple Sclerosis; Epilepsy
Link ID: 4699 - Posted: 12.16.2003