Repetitive Transcranial Magnetic Stimulation of the Human Prefrontal Cortex Induces Dopamine Release in the Caudate Nucleus
Dopamine is implicated in movement, learning, and motivation, and in illnesses such as Parkinson's disease, schizophrenia, and drug addiction. Little is known about the control of dopamine release in humans, but research in experimental animals suggests that the prefrontal cortex plays an important role in regulating the release of dopamine in subcortical structures. Here we used [11C]raclopride and positron emission tomography to measure changes in extracellular dopamine concentration in vivo after repetitive transcranial magnetic stimulation (rTMS) of the dorsolateral prefrontal cortex in healthy human subjects. Repetitive TMS of the left dorsolateral prefrontal cortex caused a reduction in [11C]raclopride binding in the left dorsal caudate nucleus compared with rTMS of the left occipital cortex. There were no changes in binding in the putamen, nucleus accumbens, or right caudate. This shows that rTMS of the prefrontal cortex induces the release of endogenous dopamine in the ipsilateral caudate nucleus. This finding has implications for the therapeutic and research use of rTMS in neurological and psychiatric disorders. Antonio P. Strafella, Tomá Paus, Jennifer Barrett, and Alain Dagher The Journal of Neuroscience, 2001, 21:RC157:1-4 Copyright © Society for Neuroscience

Keyword: Parkinsons
Link ID: 390 - Posted: 10.20.2001

Fire fought with fire
Adding more prions may slow prion disease down. ERICA KLARREICH Prions could be fought with prions, a team of US physicists propose. Their computer simulations suggest that the tiny proteins from one species might actually shield their counterparts in another species from other prions' malignant influence, slowing down disease1. Prions are thought to be the villains of transmissible spongiform encephalopathies such as BSE ('mad cow disease') and its human analogue, Creuzfeldt-Jacob Disease. The proteins are thought to attract and deform their healthy equivalents in victims' brains. The clumps that accrue can lead to dementia and death. 1.Slepoy, A. et al. Statistical Mechanics of Prion Diseases. Physical Review Letters (in press), 87, No.5, (2001). © Nature News Service / Macmillan Magazines Ltd 2001

Keyword: Prions
Link ID: 388 - Posted: 10.20.2001

Carnegie Mellon study provides conclusive evidence that cell phones distract drivers
PITTSBURGH-By studying images of the brain at work, Carnegie Mellon University scientists have concluded that we cannot converse on cell phones without distracting our brains from the task of driving. In findings reported in the journal NeuroImage, a team led by Carnegie Mellon Psychology Professor Marcel Just discovered that attending to a conversation significantly distracts the brain from processing complex visual information. "This has direct implications for cell phone use during driving because it answers one of the classic questions about human thinking. We've demonstrated that the human brain has a limited ability to perform two cognitive tasks concurrently under demanding circumstances, such as simultaneously conversing and driving," said Just.

Keyword: Attention; Vision
Link ID: 387 - Posted: 10.20.2001

The following dates and events were gathered from several sources. These events are certainly not all of the important events to take place in neuroscience...just some of the ones that I have selected. 4000 B.C. to 0 A.D ca. 4000 B.C. - Euphoriant effect of poppy plant reported in Sumerian records ca. 2700 B.C. - Shen Nung originates acupuncture ca. 1700 B.C. - Edwin Smith surgical papyrus written. First written record about the nervous system ca. 500 B.C. - Alcmaion of Crotona dissects sensory nerves 460-379 B.C. - Hippocrates discusses epilepsy as a disturbance of the brain 460-379 B.C. - Hippocrates states that the brain is involved with sensation and is the seat of intelligence 387 B.C. - Plato teaches at Athens. Believes brain is seat of mental process 335 B.C. - Aristotle writes on sleep; believes heart is seat of mental process 335-280 B.C. - Herophilus (the "Father of Anatomy"); believes ventricles are seat of human intelligence 280 B.C. - Erasistratus of Chios notes divisions of the brain

Keyword: None
Link ID: 385 - Posted: 10.20.2001

On Left-Handedness, Its Causes and Costs
By DAVID E. ROSENBAUM REDERICK, Md. -- In medieval times, right-handed warriors had a distinct advantage in swordfights. They held their shield with their left hand -- over their heart -- and thus lived to fight another day, and to reproduce, even after they had been stabbed. That, suggested Thomas Carlyle, the 19th century British writer, is why so many more people are right-handed. The lefties never lived to have offspring

Keyword: Laterality
Link ID: 384 - Posted: 10.20.2001

Don't look now, but is that dog laughing?
Susan Milius Amid all the panting, a dog at play makes a distinctive, breathy exhalation that can trigger playfulness in other dogs, says a Nevada researcher. Yes, it might be the dog version of a laugh. "To an untrained human ear, it sounds much like a pant, 'hhuh, hhuh,'" says Patricia Simonet of Sierra Nevada College in Lake Tahoe. However, this exhalation bursts into a broader range of frequencies than does regular dog panting, Simonet discovered when she and her students analyzed recordings. Simonet, O., M. Murphy, and A. Lance. 2001. Laughing dog: Vocalizations of domestic dogs during play encounters. Animal Behavior Society conference. July 14-18. Corvallis, Oregon. From Science News, Vol. 160, No. 4, July 28, 2001, p. 55. Copyright ©2001 Science Service. All rights reserved.

Keyword: Animal Communication
Link ID: 383 - Posted: 10.20.2001

Teaching Old Pains New Tricks Links with Learning And Memory Provide Clues Why Pain Persists
Some people just learn about pain all too well. That's the growing notion among neuroscientists and anesthesiologists, who are finding evidence that chronic, persistent pain, including the phantom pain experienced by many amputees and people with spinal cord injuries, is learned, much like our own memories. Such pain is very real and oftentimes severe. Approximately 60 percent of patients with spinal cord injuries suffer phantom pain - though they have no sensation or ability to move their arms or legs, they still feel pain from those limbs. Within weeks or months of the initial injury, more patients than not report tingling, pins-and-needles pain, and burning and stabbing pain that may never go away. The same can be true with other profound injuries, such as bullet or stab wounds, or from conditions like cancer, diabetes or arthritis. ©Copyright University of Rochester Medical Center, 1999-2001.

Keyword: Pain & Touch; Learning & Memory
Link ID: 381 - Posted: 10.20.2001

Races' face discrimination The brain lights up in race recognition.
HELEN PEARSON Recognizing a face is easier when its owner's race matches our own. An imaging study now shows that greater activity in the brain's expert face-discrimination area may explain this phenomenon - one of the first times that a social group's effects on behaviour have been pinned on a brain centre. "We were able to pinpoint where and when race matters at a neural level," says Jennifer Eberhardt of Stanford University, California. She and her colleagues recorded activity in the fusiform face area (FFA) of the brain as African- or European-Americans studied pictures of faces from different races. The FFA was more active when either group was learning and recognizing faces of the same race, they found1. References 1.Golby, A. J., Gabrieli, J. D. E., Chiao, J. Y. & Eberhardt, J. L. Differential responses in the fusiform region to same-race and other-race faces. Nature Neuroscience, 4, 845 - 850, (2001). 2.Gauthier, I., Skudlarski, P., Gore, J. C., & Anderson, A. W. Expertise for cars and birds recruits brain areas involved in face recognition. Nature Neuroscience, 3, 191 - 197, (2000). © Nature News Service / Macmillan Magazines Ltd 2001

Keyword: Learning & Memory; Brain imaging
Link ID: 380 - Posted: 10.20.2001

Researchers at the University of Illinois at Chicago, working with yeast, have made the startling finding that the presence of one prion protein can spark the formation of other unrelated prions similar to the protein thought to cause "mad cow" and other diseases of mammals and man. The researchers also devised a screening test that can be used to pinpoint unidentified prions, making it the first such genetic assay for these mysterious biological agents. The findings are reported in the July 27 issue of the journal Cell by UIC biology professor Susan Liebman and three co-workers. A prion, the causative agent of "mad cow" disease and human Creutzfeldt-Jakob disease, is an improperly folded protein molecule that clumps together and corrupts other, healthy molecules of the same protein to do likewise, in domino fashion.

Keyword: Prions
Link ID: 379 - Posted: 10.20.2001

For peppers, ‘hot' quite literally the spice of life
GAINESVILLE, Fla. --- It adds the fire to chili and the hot to salsa, but what does the zing do for the pepper? As it turns out, quite a lot. Working with the ancestor of most varieties of chili pepper plants, a University of Florida researcher has shown that the plant relies on its spiciness to ensure the very survival of its species. In an article set to appear in Nature on Thursday, Josh Tewksbury, a UF postdoctoral researcher in zoology, and co-author Gary Nabhan, an ethnobotanist at Northern Arizona University, conclude that mammals, sensitive to the chemical that makes peppers taste hot, avoid the Capsicum annuum pepper. Birds, however, are unaffected by the chemical, known as capsaicin, and they happily eat the peppers. This is essential for the plant, since birds release the seeds in their droppings ready to germinate -- whereas if mammals ate the seeds, they would crunch them up or render them infertile, the researchers report.

Keyword: Pain & Touch; Evolution
Link ID: 378 - Posted: 06.24.2010

Poor reading skills have both physical, environmental causes
Reading problems in young children may be influenced by a combination of both neurological and environmental factors, according to a new study. "Children may fail to develop adequate reading skills because of their environment, abnormal brain structure, or both," says lead study author Mark A. Eckert, Ph.D., of the McKnight Brain Institute of the University of Florida. The researchers found that reading skill and verbal ability were predicted by asymmetry of the temporal plane, a brain area that processes auditory information. Poorly performing children had more symmetrical temporal planes, compared with a left-weighted asymmetry which is more commonly seen.

Keyword: Dyslexia; Laterality
Link ID: 377 - Posted: 10.20.2001

The National Institute of Mental Health (NIMH) has launched a new study of women ages 21 to 45 who are suffering from major depression to find out whether low bone mass is related to depression or stress hormones, such as cortisol. During a 12-month period, researchers will monitor bone loss and the effects of depression and stress on physical health. The trial involves 6 visits to NIMH, where participants will receive a psychological evaluation, a bone mineral density test, and measurements of stress hormones. In a review of published research, NIMH-funded scientists report a strong association between depression and osteoporosis. The literature suggests that depression may be a significant risk factor for osteoporosis, a progressive decrease in bone density that makes bones fragile and more likely to break. Low bone mineral density (BMD), a major risk factor for fracture, is more common in depressed people than in the general population.

Keyword: Depression; Hormones & Behavior
Link ID: 373 - Posted: 10.20.2001

Manipulating A Single Gene Dramatically Improves Regeneration in Adult Neurons:
Finding May Lead to New Approaches for Treating Brain and Spinal Cord Damage Overview Increasing the expression of a single gene that is important during development dramatically improves the ability of adult neurons to regenerate, a new study shows. The finding suggests that intrinsic properties of neurons play an important role in controlling neuronal regeneration and may lead to new approaches for treating damage from stroke, spinal cord injury, and other neurological conditions. The study examined how genetically engineering adult neurons to produce larger amounts of a type of protein called integrin affects nerve fiber growth. This approach is one of the first to examine "the critical missing half of the regeneration equation: the properties of adult neurons, rather than the environment of the adult brain," says study investigator Maureen L. Condic, Ph.D., of the University of Utah School of Medicine in Salt Lake City. The work was supported by the National Institute of Neurological Disorders and Stroke (NINDS) and will appear in the July 1, 2001, issue of the Journal of Neuroscience.1

Keyword: Regeneration; Genes & Behavior
Link ID: 372 - Posted: 10.20.2001

New Tool Allows Early Prediction of Patient's Stroke Outcome
Overview Scientists have developed a new tool that may help physicians predict, during the first several hours a stroke patient is in the hospital, the degree of recovery the patient will eventually experience. The tool uses three factors for the accurate prediction of stroke outcome: measurement of brain injury using magnetic resonance imaging (MRI); the patient's score on the NIH stroke scale; and the time in hours from the onset of symptoms until the MRI brain scan is performed. Baird, A.E., Dambrosia, J., Janket, S., Eichbaum, Q., Chaves, C., Silver, B., Barber, P.A., Parsons, M., Darby, D., Davis, S., Caplan, L.R., Edelman, R.R., Warach, S. "A Three-Item Scale for the Early Prediction of Stroke Recovery." Lancet, June 30, 2001, Vol. 357, No. 9274, pp. 2095-2099.

Keyword: Stroke; Regeneration
Link ID: 371 - Posted: 10.20.2001

May lead to improved treatment for spinal cord injury In a series of animal experiments, scientists show for the first time that damage to the central nervous system causes the body to mount an immune reaction against itself that actually protects neurons from further damage. The findings may lead to a vaccine to improve functional recovery following spinal cord injury. The findings also challenge accepted dogma that immune activity in the central nervous system is harmful, and that immune response against the body's own tissue, known as an autoimmune response, is destructive. "We show that this autoimmune response can help the individual to cope with stress caused by the injury," says lead author Michal Schwartz, PhD, of the Weizmann Institute of Science in Rehovot, Israel. The study, funded in part by Proneuron, Ltd., an Israeli biotechnology company, appears in the June 1 issue of The Journal of Neuroscience. Schwartz has an equity position in Proneuron.

Keyword: Regeneration
Link ID: 370 - Posted: 10.20.2001

Taste Detectors
For years, the molecular underpinnings of taste have been elusive. But now several studies are helping shed new light on this sense. Most recently, researchers uncovered evidence of certain proteins that recognize some of the flavor-producing chemicals in food and launch the taste signals that head to the brain for interpretation. The research is helping scientists understand how the brain interprets taste signals and may lead to methods that can enhance or block flavors of foods, beverages and medications.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 369 - Posted: 10.20.2001

Violent Brains
Clearly, many factors lead a person to commit a violent act. Researchers are now finding out how biology may enter into the equation. Accumulating studies on animals and humans, for one, suggest that certain brain regions may sometimes contribute to violent behavior. The research is providing new insights into the biology behind violence and may lead to new ways to control it.

Keyword: Aggression
Link ID: 368 - Posted: 10.20.2001

For years, researchers have successfully battled disease-breeding germs by using vaccines to pump up defending troops of antibody proteins in the body. Researchers now hope to spread some of the wealth. An increasing amount of new evidence, culled from animal work, indicates that antibody strategies can attack and bind up or destroy targeted drugs such as cocaine, PCP, methamphetamine and the nicotine in cigarettes. The techniques may provide new medicines to help keep abusers off drugs as well as treat an overdose.

Keyword: Drug Abuse
Link ID: 367 - Posted: 10.20.2001

Parental Care and The Brain
Many researchers have suspected that infants must benefit from the close physical attention of their caregivers, but the extent and nature of the benefit was unclear. Now an increasing amount of biological research on animals is determining that while a number of factors are vital for proper brain development, physical attention appears to play a role in maintaing brain chemistry, brain architecture and possibly some mental functioning. Researchers hope that the insights will lead to new strategies that can boost the effects of human parenting in normal situations, as well as treat neglected children.

Keyword: Stress
Link ID: 366 - Posted: 10.20.2001

Dyslexia and Language Brain Areas
The learning disability dyslexia, which centers on difficulties in reading, once stumped scientists. Since dyslexics often have good intelligence and even may be gifted in some areas, it was thought that a little motivation could get them on the right track. Now researchers not only know that dyslexia is born of biology, but they also are getting closer to confirming the key brain areas that are affected. New insights will help pinpoint therapies and improve treatment.

Keyword: Dyslexia
Link ID: 365 - Posted: 10.20.2001