By Eric Haseltine The page you are reading now looks flat and feels flat, but your brain isn't so certain. That's because when the human brain evolved into its current form about 30,000 years ago, it was programmed for interpreting 3-D objects, especially predators, not images on flat surfaces. As a result, your brain plays tricks on you. For example, the dimensions of the two tabletops above look different, but they are actually identical. The front edge of the table on the left is the same length as the left edge of the table on the right, but it looks shorter because perspective makes it appear closer and therefore smaller. Similarly, the front and rear edges of the right-hand table are actually longer than the apparently receding long edges of the left-hand table. Although many optical illusions depend upon erroneous transformations of two dimensions into three, your brain's tendency to project depth onto flat surfaces can occasionally help it correctly interpret what it sees.

Keyword: Vision
Link ID: 3205 - Posted: 12.20.2002

By ERICA GOODE Clozapine, one of a new generation of anti-psychotic drugs, has become the first psychiatric medication to win federal approval as a treatment for suicidal behavior. The Food and Drug Administration announced yesterday that the agency had approved the drug for treating recurrent suicidal thoughts or suicide attempts in patients with schizophrenia, a devastating illness that afflicts 1 of 100 Americans. Clozapine was first marketed in 1989 by Novartis under the brand name Clozaril. But the company's exclusive rights to sell the drug expired in 1994, and the medication is also available in generic form. Copyright The New York Times Company

Keyword: Schizophrenia; Depression
Link ID: 3204 - Posted: 12.20.2002

Dian Land The slightest turn of the head can significantly change the way a person or animal detects sound. A subtle tilt alters the angle at which high-frequency sound waves hit the ear, providing cues to localize the sound. To use those cues, the brain must put what it hears into the context of the position of the head. Until recently, scientists were not sure how this was done. Now researchers at UW Medical School appear to have the explanation. They have discovered that in the cochlear nucleus, the first sound-processing station in the brain, certain cells accomplish the job by integrating the two kinds of information, each of which travels along a distinct pathway. The researchers compared activity in both pathways, examining currents running through synapses--or signal-transmitting junctions--in fusiform cells of the cochlear nucleus. To their surprise, they learned that synapses transmitting acoustic information were not influenced by previous activity--they were stable. On the other hand, synapses carrying information about head and ear position were continually strengthened or weakened depending on the amount of activity-they were plastic. Copyright © 2002 The Board of Regents of the University of Wisconsin System.

Keyword: Hearing
Link ID: 3203 - Posted: 06.24.2010

Research continues in an effort to determine if these neural cells can be transplanted to treat stroke, brain tumors and neurodegenerative disorders LOS ANGELES – Researchers at Cedars-Sinai's Maxine Dunitz Neurosurgical Institute have for the first time demonstrated that stem cells from whole adult bone marrow can be differentiated into several types of cells of the central nervous system. A long-term objective of this research is to determine if these neural stem cells can be transplanted to treat stroke, brain tumors and neurodegenerative disorders. This capability would give physicians a renewable source of neural progenitor cells, available from a patient's bone marrow instead of the brain, and without the ethical and tissue-rejection issues associated with the use of fetal stem cells. Results of the study appear as the cover article of the December issue of the journal Experimental Neurology. While this study was conducted in rats, similar optimistic results have been seen in human tissue, according to senior author John S. Yu, M.D., Co-director of the Comprehensive Brain Tumor Program at the Neurosurgical Institute.

Keyword: Stem Cells
Link ID: 3202 - Posted: 06.24.2010

Much of the construction of an image takes place in the retina itself through the use of specialized neural circuits The retina, the filmy piece of tissue lining the back of the eyeball, is considered the best understood part of the brain. Intricate exchanges among the neurons of the retina allow much image construction to take place in the eye itself. Visual perception begins within cells called photoreceptors, where proteins embedded in cell membranes change shape when exposed to light. Layers of other retinal cells transfer signals from the photoreceptors to the optic nerve. The intervening layers process the signals--among other tasks, adjusting neural responses under different lighting conditions and increasingly distinguishing objects from their backgrounds. Vision researchers estimate that careful study of the anatomy and physiology of the vertebrate retina has clarified about half of all the interactions in this tissue. Helga Kolb is professor emeritus of ophthalmology and visual sciences at the University of Utah. She studied at the University of Bristol, completing her Ph.D. in 1971. She conducted eye research at the Institute of Ophthalmology in London, where she became involved in studies of electrophysiology and anatomy, and later moved to positions at Johns Hopkins and the National Institutes of Health. She joined the Utah faculty in 1979. © American Scientist 2003

Keyword: Vision
Link ID: 3201 - Posted: 06.24.2010

By Steve Connor, Science Editor New technology has allowed scientists to witness for the first time how experiences and memories are laid down in the brain as electrical circuits made from nerve tissue. The findings shed light on learning and memory, and could lead to alternative ways of dealing with brain damage and mental retardation, the scientists said. Two teams of researchers have independently observed microscopic "spines" growing and retracting from the ends of nerve cells in the brains of adult mice over a period of several days. They believe the spines move in response to memories and experiences the mice come across as they explore a new environment. © 2002 Independent Digital (UK) Ltd

Keyword: Learning & Memory
Link ID: 3200 - Posted: 06.24.2010

Neuroscientists see different pictures through windows on rodent brain. HELEN PEARSON Two US teams have built a window on a mouse's mind. But after peering through it at brain cells in action, they have conflicting ideas about how memories are stored. The groups made pin-sized portholes from glass or skull bone. Beneath, the genetically modified nerves glowed green or yellow under a microscope. "People have been waiting for a way to peer into the living brain," says neuroscientist Ole Ottersen of the University of Oslo in Norway. © Nature News Service / Macmillan Magazines Ltd 2002

Keyword: Learning & Memory
Link ID: 3199 - Posted: 06.24.2010

ALEX DOMINGUEZ Associated Press Scientists have found a way to track tiny features of individual brain cells in living mice, providing a glimpse at how brains change over time. In one case, they watched the animals' brains rewire after their whiskers were clipped. The technique will help scientists explore how the brain forms memories and reacts physically to its owner's experiences. The advance "will have far-reaching implications" for studying the brain, according to Ole P. Otterson and P. Johannes Helm of the University of Oslo in Norway. They wrote a commentary that accompanies two reports on the technique in Thursday's issue of the journal Nature.

Keyword: Learning & Memory
Link ID: 3198 - Posted: 12.19.2002

NewScientist.com news service The British High Court has given the go-ahead for two teenagers dying from vCJD to be the first to receive an experimental treatment. It would involve injections of a drug called pentosan polysulphate directly into their brains. Pentosan polysulphate is currently used as an oral drug in people to treat cystitis and bladder pain. Research in the UK and Japan has shown that the drug can stop the progression of scrapie, a very similar disease, in mice. It worked by binding to a key site on cells and stopping abnormal prion proteins being created. But research in the field is at an early stage. In October 2002, the UK's Committee on the Safety of Medicines reviewed all existing data on the drug and concluded it was too early to consider using it in human vCJD patients. © Copyright Reed Business Information Ltd.

Keyword: Prions
Link ID: 3197 - Posted: 06.24.2010

Findings could lead to advances for thousands who have lost their ability to taste after treatment for cancer, other disorders of the mouth - Bethesda, MD – Surgery and a wide range of cancer treatments on the tongue can be devastating for both its short- and long- term considerations. A recent study conducted at Duke University, for example, found that patients who experience taste and smell loss because of the disease and its treatments are at high risk for weight loss and nutritional deficits that can compromise their overall treatment success. Even among patients who are eating the same volume of calories, those with taste and smell distortions may avoid foods with high nutritional value, such as fresh fruits and vegetables. Eliminating such nutritious foods can further depress immune function. The causes of taste loss vary. Chemotherapy drugs are known to alter taste and smell by blunting the normal turnover rate of taste and smell receptors on the tongue and in the nasal passages. Radiation treatments can also damage taste and smell receptors, giving food a metallic flavor. Tumors themselves also secrete a protein that suppresses appetite in some patients. Often it is the need to perform surgery on the tongue itself.

Keyword: Chemical Senses (Smell & Taste); Regeneration
Link ID: 3196 - Posted: 06.24.2010

Ongoing studies by Duke and Florida researchers to determine the genders of turtle hatchlings are already revealing potentially alarming findings about a threatened species BEAUFORT, N.C. -- As part of a large-scale project to preserve loggerhead sea turtles, researchers from three institutions have been raising about 1,200 hatchlings though their first months and are now releasing them after identifying the animals’ genders. These ongoing studies are already revealing an unexpectedly small percentage of males among baby turtles collected from Carolina and Georgia beaches, which could have negative implications for the future of the entire Southeastern loggerhead population, the investigators report. The scientists said this is the first time so many loggerhead hatchlings have been raised and studied so intensely. The research is intended to provide information critical to boosting the numbers of the threatened species. As a bonus, the selected animals are able to avoid the predators hatchlings normally face when they crawl from nest to surf to begin their lives at sea. © 2002 Duke News Service

Keyword: Sexual Behavior
Link ID: 3195 - Posted: 06.24.2010

Bethesda, MD - That people are getting fatter is not news. Around the globe, physically demanding occupations like farming and mining are now carried out by machines. Western values such as television and automobiles are now encroaching on the most isolated environments. Finally, a highly processed diet -- along with a sedentary lifestyle -- is the likely culprit in the high rates of obesity seen among indigenous peoples who were originally hunters and foragers. Now they eat a diet that is "entirely store bought and provided by truck." Scientists and anthropologists have observed that in some societies, a high rate of infectious disease seems to be keeping children's weight low or substandard while many of the adults are obese. In effect, very small children evolve very quickly into obese adults. The aesthetic qualities of obesity are the least of the problems associated with this spike in worldwide weight gain. The disorder is associated with an increased risk of life threatening conditions such as diabetes, hypertension and heart diseases, and weight loss has been reported to ameliorate these associated conditions. To prevent these chronic disorders, some try to reduce weight by caloric restriction; however the effort generally fails as most obese patients regain their lost weight thereafter. Therefore, medicinal treatment becomes a necessity. One facet currently being explored is the central regulators of food intake. This includes the cannabinoid system with its putative endogenous ligands anandamide and 2-arachidonoyl glycerol (2-AG). In addition to its many pharmacological activities, this system has been implicated in food intake regulation.

Keyword: Obesity; Drug Abuse
Link ID: 3194 - Posted: 12.18.2002

Despite the considerable effort that leaders in the field of clinical psychology have taken to make the diagnosis of mental disorders an "objective" process, the theoretical beliefs of clinicians still appear to play a major role in the process. That is the conclusion of a study published in this month's issue of the Journal of Experimental Psychology, General conducted by Woo-kyoung Ahn, associate professor of psychology at Vanderbilt, and Nancy Kim, visiting faculty at Wesleyan University. "For the last 22 years, clinical psychologists have been told that they should make diagnoses based solely on a checklist of symptoms. But our results indicate that individual theories still play a surprisingly strong role. Clinicians are significantly more likely to diagnose patients with a mental disorder when the person exhibits symptoms that are central in the clinician's own theories of the disorder. Similarly, they are far less likely to make the same diagnosis for a patient with symptoms that they consider to be peripheral," says Ahn.

Keyword: Depression; Schizophrenia
Link ID: 3193 - Posted: 06.24.2010

Babies born during the summer months have a greater chance of developing the digestive disorder coeliac disease, research suggests. Coeliac disease sufferers have an intolerance to gluten, a protein found in wheat, and similar proteins in rye, barley and oats. Around three in 100 people in the UK are thought to be affected. The only way to manage the condition is to eat a gluten-free diet. Scientists at Umea University in Sweden identified 2,151 children with coeliac disease from a national register of child health covering the period from 1973 to 1997. They found the risk of coeliac disease was significantly higher for children born in the summer compared with the winter - but only in children who were under two when they were diagnosed. (C) BBC

Keyword: Biological Rhythms; Autism
Link ID: 3192 - Posted: 12.17.2002

NewScientist.com news service Males are better at tolerating pain than females because of a key difference in how the sexes transmit pain messages, researchers have found. A protein called GIRK2 plays a major role in pain sensation and drug sensitivity in males, but is not as important in females. Removing GIRK2 means the sexes become equal in their ability to withstand pain, experiments on mice showed. Taking account of this difference could in the future lead to far more effective painkillers for women. Previous studies show that men have higher pain thresholds than women. This is despite conventional wisdom suggesting the opposite, since women endure intense pain during childbirth. © Copyright Reed Business Information Ltd.

Keyword: Pain & Touch; Genes & Behavior
Link ID: 3191 - Posted: 06.24.2010

by John E. Schowalter, M.D. Psychiatric Times December 2002 Vol. XIX Issue 12 Clinicians who work with children face particular ethical issues, but they are not exempted from the general ethical considerations that face all mental health clinicians. Almost always, psychiatric treatment for minors is initiated not by the patient, but through the pressure of others. In most instances, the pressure is from parents, physicians, school personnel and/or legal authorities. Since child psychiatric patients are especially vulnerable to coercion by others, their clinicians must be particularly careful to know their own ethical responsibilities and their patients' rights. Many practitioners remember the Accreditation Council for Graduate Medical Education residents' required lectures and seminars on ethics as dull, irrelevant or skipped. Learned physicians (Brewin, 1993) have questioned the usefulness of teaching ethics, at least of an "academic" type, rather than the more clinically based type. I agree, but I believe the quite common negative response of residents' exposure to ethics is not due mainly to poor teaching. I believe it is because ethics, once acknowledged, demand complicated, uncomfortable thinking. It is much easier to only think of other peoples' ethics, not our own. (C) 2003 Psychiatric Times. All rights reserved.

Keyword: Development of the Brain; Depression
Link ID: 3190 - Posted: 12.17.2002

By ANNA FELS, M.D. One afternoon in my psychiatric practice, I saw two patients suffering from depression in back-to-back sessions. Each had classic symptoms, including what is called diurnal variation of mood: depressed patients typically feel worse in the morning and get better toward evening. The pattern is believed to be caused by the daily fluctuations of hormones and neurotransmitters. This theory was not, however, how my patients understood their symptoms. The first patient explained that he felt bad during the day because of work pressures, and he improved in the evening because he was alone and could relax. The second patient, a musician, said her solitary days made her depressed; it was only when she arrived at work in the evenings and was around people that she felt like herself. Copyright The New York Times Company

Keyword: Depression
Link ID: 3189 - Posted: 12.17.2002

By ERICA GOODE In this season of bickering relatives and whining children, of overcrowded department stores and unwritten Christmas cards, it is instructive to consider the plight of the Pacific salmon. As the fish leap, flop and struggle upstream to spawn, their levels of cortisol, a potent stress hormone, surge, providing energy to fight the current. But the hormone also leads the salmon to stop eating. Their digestive tracts wither away. Their immune systems break down. And after laying their eggs, they die of exhaustion and infection, their bodies worn out by the journey. Salmon cannot help being stressed out. They are programmed to die, their systems propelled into overdrive by evolutionary design. Copyright The New York Times Company

Keyword: Stress
Link ID: 3188 - Posted: 12.17.2002

Obsessive-compulsive disorder (OCD) is a severe psychiatric illness. The onset of disease often occurs during childhood. OCD is characterized by recurrent and intrusive thoughts (obsessions), usually accompanied by repetitive behaviours (compulsions), the person feels to be driven to perform, e.g. excessive washing of hands. Insight is generally preserved, thus the patient acknowledges the senseless nature of the symptoms. An extensive body of evidence supports the involvement of genetic components in the pathogenesis of OCD. OCD can be effectively treated with serotonin reuptake inhibitors, thus, it has been suggested that genes involved in the serotonergic system may be involved in the aetiology of this disorder. The University clinic for Child and Adolescent Psychiatry of Würzburg has investigated the etiology of early onset OCD in both family-based studies and longitudinal studies for many years. These studies demonstrated high prevalence of this disorder in the relatives of OCD patients. This supports the hypothesis that genetic factors play a role in OCD disease etiology.

Keyword: OCD - Obsessive Compulsive Disorder; Genes & Behavior
Link ID: 3187 - Posted: 12.17.2002

Several lines of evidence suggest that a partially genetically controlled serotonergic dysfunction is involved in the biological pathogenesis of suicide. To investigate the involvement of serotonergic dysfunction in suicide victims, Japanese scientists measured the protein level of tryptophan hydroxylase (TPH), the rate-limiting enzyme in serotonin biosynthesis, as a pre-synaptic maker. They also measured serotonin receptor 2A (5HT2A receptor) density as a post-synaptic marker in the serotonergic system in postmortem brains of 10 suicide victims and 12 controls. In addition, to clarify the genetic involvement in serotonergic function, the authors examined whether the variations of the TPH gene could affect TPH protein level, and whether those of the 5HT2A receptor gene could affect 5HT2A receptor density in 28 postmortem brain samples. No significant differences were found in TPH protein level or 5HT2A receptor density between suicide victims and controls. There was a significant negative correlation, however, between TPH protein level and 5HT2A receptor density. The variation of the TPH gene (the A218C polymorphism: a single base transition, A to C) had a significant influence on both TPH protein level and 5HT2A receptor binding. The AA genotype of the A218C polymorphism of the TPH gene showed higher TPH protein level along with lower 5HT2A receptor density than did any other genotypes in the postmortem brains of both suicide victims and controls.

Keyword: Depression; Genes & Behavior
Link ID: 3186 - Posted: 06.24.2010