BrainBlog

Takahashi T. Time-estimation error following Weber-Fechner law may explain subadditive time-discounting. . Medical Hypotheses. 2006 Jul 25; [Epub ahead of print] Department of Cognitive and Behavioral Science, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan. Impulsivity in drug addicts have been associated with impatience in intertemporal choice, i.e., high degrees to which delayed rewards are discounted, indicating the importance of reducing the degree of discounting in drug addicts. Intertemporal choice (delay discounting) has been attracting attention in neuropsychopharmacology and behavioral neuroeconomics. Recently, behavioral economists have reported that impatience/impulsivity in intertemporal choice is increased if a delay period is presented as a sum of divided time-blocks, which is referred to as subadditive discounting (i.e., "total patience" over the delay period is larger than the "sum of patience" over divided delay periods). This...

International Neuropsychological Society (INS) mid-year conference taking place this week in Zurich, Switzerland. Visit the conference website for more information: website . - Anthony H. Risser | neuroscience | neuropsychology | brain

Most everyone reading this will have had a closer degree of connection with Virginia Apgar than they know. Who is Virginia Apgar, you ask? When born, most of you will have received an Apgar Score in the delivery room. She created it. Did you know?... (grin) virginia and her brother From an NIH press release on the 13th of July: Papers of Virginia Apgar Added to National Library of Medicine's Profiles in Science Web Site Bethesda, Maryland - The National Library of Medicine's Profiles in Science Web site has been enriched by the addition of the papers of Virginia Apgar, M.D., creator of the widely used Apgar Score to evaluate newborns. The Library has collaborated with the Mount Holyoke College Archives and Special Collections to digitize her papers and make them widely available. This brings to 18 the number of notable scientists who have personal and professional recor...

I received a couple of new books on neuroethics from The Dana Center. The first one I started to read is Mind Wars: Brain Research and National Defense by bioethicist Jonathan D. Moreno, Ph.D. It's been a fascinating read so far. The cover blurb points to coverage of how neuroscience may influence warfare and the ethical and policy issues that are likely to be confronted. I'm curious as to what arguments and points will emerge in Moreno's presentation! The other book is Hard Science, Hard Choices: Facts, Ethics, and Policies Guiding Brain Science Today by Sandra J. Ackerman. - Anthony H. Risser | neuroscience | neuropsychology | brain

Last week's issue of The New Yorker (03 July 2006) included an excellent Annals of Medicine essay on hemispherectomy, The Deepest Cut, written by Christine Kenneally. She follows the lives of two individuals, Lacy and Christina, and provides a succinct overview to the indications for this operative procedure and its outcomes. - Anthony H. Risser | neuroscience | neuropsychology | brain

Cummings JL, McRae T, & Zhang R. (2006). Effects of donepezil on neuropsychiatric symptoms in patients with dementia and severe behavioral disorders. American Journal of Geriatric Psychiatry, 14(7), 605-612. Departments of Neurology and Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, Los Angeles, California (JLC); and Pfizer, Inc., New York, New York (TM, RZ). Objective: The objective of this study was to conduct exploratory analyses of data pertaining to the efficacy of donepezil treatment of patients with severe behavioral disturbances. Preliminary studies suggest that cholinesterase inhibitors, including donepezil, may reduce behavioral disturbances in patients with Alzheimer disease (AD). Most patients included in clinical trials have had low levels of psychopathology at baseline, and the effect of cholinesterase inhibitors on patients with more severe behavioral disturbances is unknown. The authors report the effects of donepezil on behavioral...

From an NIH press release on 04 July 2006: Dopamine Drug Leads to New Neurons and Recovery of Function in Rat Model of Parkinson's Disease In preliminary results, researchers have shown that a drug which mimics the effects of the nerve-signaling chemical dopamine causes new neurons to develop in the part of the brain where cells are lost in Parkinson's disease (PD). The drug also led to long-lasting recovery of function in an animal model of PD. The findings may lead to new ways of treating PD and other neurodegenerative diseases. The study was funded in part by the NIH's National Institute of Neurological Disorders and Stroke (NINDS). The study suggests that drugs which affect dopamine D3 receptors might trigger new neurons to grow in humans with the disease. Some of these drugs are commonly used to treat PD. The finding also suggest...

Zach Lynch of Brain Waves points to a recent Op-Ed piece in The Washington Post by the CEO of Wyeth, Robert Essner: Read the post, with a link to the piece - Anthony H. Risser | neuroscience | neuropsychology | brain

From the Canadian Broadcasting Corporation (CBC): Ants walk using internal distance clock: Study Last Updated Fri, 30 Jun 2006 15:43:19 EDT CBC News Desert ants have an internal pedometer that measures how far they've marched, researchers have found. Foraging Sahara Desert ants wander when searching for food, but take a relatively straight path when heading back to their nests. To do so, the ants need to judge directions and distances when travelling over flat, sandy terrain without landmarks. Scent trails used by other species won't work because the odours fade in the hot desert. [...continues...] [ ... Read the full report ... ] - Anthony H. Risser | neuroscience | neuropsychology | brain

From The New York Times : City Tackles Meningitis in Brooklyn By RICHARD PÉREZ-PEÑA The New York Times 29 June 2006 City health officials yesterday announced a novel assault on a large meningitis outbreak in Brooklyn, seeking to vaccinate thousands of drug users and others in and around Bedford-Stuyvesant against the bacterium that has sickened 23 people and killed eight of them. That group of cases, over the past seven months, "is one of the largest outbreaks of meningitis described in the U.S. literature in the last couple of decades," said Health Commissioner Thomas R. Frieden. And the department's response, a mass vaccination for meningococcal meningitis , made possible by a new, more effective vaccine, appears to be the first in the city's history, he said. [ ... Read the full article ... ] - Anthony H. Risser | neuroscience | neuropsychology | brain

From an NIH press release: Neurons Grown from Embryonic Stem Cells Restore Function in Paralyzed Rats For the first time, researchers have enticed transplants of embryonic stem cell-derived motor neurons in the spinal cord to connect with muscles and partially restore function in paralyzed animals. The study suggests that similar techniques may be useful for treating such disorders as spinal cord injury, transverse myelitis, amyotrophic lateral sclerosis (ALS), and spinal muscular atrophy. The study was funded in part by the NIH’s National Institute of Neurological Disorders and Stroke (NINDS). The researchers, led by Douglas Kerr, M.D., Ph.D., of The Johns Hopkins University School of Medicine, used a combination of transplanted motor neurons, chemicals capable of overcoming signals that inhibit axon growth, and a nerve growth factor t...

Salter K, Jutai J, Foley N, Hellings C, & Teasell R. (2006). Identification of aphasia post stroke: A review of screening assessment tools. Brain Injury, 20(6), , 559-568. Department of Physical Medicine and Rehabilitation, Parkwood Hospital, St. Joseph's Health Centre, London, Ontario, Canada. Introduction: Aphasia is one of the most common consequences of stroke. Early identification, diagnosis and treatment of language deficits are important steps in maximizing rehabilitation gains. A routine screening test is an invaluable tool in the identification and appropriate referral of patients with potential communication problems. The present study presents an evaluation of the measurement properties of screening tools for aphasia found within the stroke research literature.Methods: Screening tools were identified following searches of the published research literature in stroke. Instruments were reviewed on the basis of reliability, validity, classification sensitivity and prac...

From an NIH press release: Easy-to-Read Booklets on Alzheimer’s Disease, Memory Loss Offered by NIA The National Institute on Aging (NIA), a component of the National Institutes of Health, now offers two free booklets designed to help people with limited literacy skills learn about Alzheimer’s disease (AD) and memory loss. In these easy-to-read booklets, the medical and technical language has been replaced by plain language, stories, photographs, and other features to help readers understand the content. “Our goal was to produce strong, clear materials to make information about AD and memory loss accessible to everyone, including those with limited literacy skills,” says Richard J. Hodes, M.D., director of the NIA. “These booklets also are excellent starting points for anyone who needs basic information about AD and memory prob...

From the FDA on the 17th of May: FDA Approves New Treatment for Parkinson's Disease The Food and Drug Administration today approved Azilect (rasagiline), a new molecular entity, for the treatment of Parkinson's disease. The drug is a monoamine oxidase type--B (MAO-B) inhibitor that blocks the breakdown of dopamine, a chemical that sends information to the parts of the brain that control movement and coordination. "This is a welcome development for the more than 50,000 Americans who are each year diagnosed with Parkinson's disease, " said Dr. Steven Galson, Director of the Center for Drug Evaluation and Research. "Parkinson's is a relentless disease with limited treatment options, and each new therapy is an important addition to the physicians' treatment options." [snip] Azilect was approved for use as an initial single drug therapy in early Parkinson's disease, and as an addition to levodopa in more advanced patients.  Levodopa i...

From today's New York Times : Study Points to a Solution for Dread: Distraction By SANDRA BLAKESLEE Published: May 5, 2006 The New York Times For those who dread a colonoscopy or a root canal so much that they avoid it altogether, scientists have good news. The first study ever to look at where sensations of dread arise in the brain finds that contrary to what is widely believed, dread does not involve fear and anxiety in the moment of an unpleasant event. Instead, it derives from the attention that people devote beforehand to what they think will be extremely unpleasant. So the solution to dread, the researchers say, is self-distraction. "We sort of knew that things like self-hypnosis help relieve dread, but now we know why," said Dr. Gregory S. Berns, a professor of psychiatry and behavioral sciences at Emory University, who led the study. The research, being published today in the journal Science , is "terrific, " said a leading expert on brain imaging, Dr. R...

DeKosky ST, Fitzpatrick A, Ives DG, Saxton J, Williamson J, Lopez OL, Burke G, Fried L, Kuller LH, Robbins J, Tracy R, Woolard N, Dunn L, Kronmal R, Nahin R, & Furberg C; for the GEMS Investigators. The Ginkgo Evaluation of Memory (GEM) study: Design and baseline data of a randomized trial of Ginkgo biloba extract in prevention of dementia. Contemp Clinical Trials. 2006 Apr 18; [Epub ahead of print]. Department of Neurology, University of Pittsburgh, 3471 Fifth Avenue, Suite 811, Pittsburgh, PA 15213, USA. The epidemic of late life dementia, prominence of use of alternative medications and supplements, and initiation of efforts to determine how to prevent dementia have led to efforts to conduct studies aimed at prevention of dementia. The GEM (Ginkgo Evaluation of Memory) study was initially designed as a 5-year, randomized double-blind, placebo-controlled trial of Ginkgo biloba, administered in a dose of 120 mg twice per day as EGb761, in the prevention of dementia (and especial...

From Weblogsky : " Farewell to Dr. Tom "

NBC's Dateline this evening covers Parkinson's Disease. Centering on the work of Michael J. Fox and his Foundation , it also includes segments with Muhammed Ali and his clinical center at the Barrow Neurological Institute in Phoenix and with several neuroscientists. - Anthony H. Risser | neuroscience | neuropsychology | brain

Nakagawasai O, Yamadera F, Sato S, Taniguchi R, Hiraga H, Arai Y, Murakami H, Mawatari K, Niijima F, Tan-No K, & Tadano T. Alterations in cognitive function in prepubertal mice with protein malnutrition: relationship to changes in choline acetyltransferase. Behavior and Brain Research. 2006 Feb 15; 167(1): 111-117. Department of Pharmacology, Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan. We have found that protein malnutrition (PM) causes a significant impairment of memory-related behavior on the 15th and 20th day after the start of PM (5% casein) feeding in prepubertal mice but not in postpubertal mice, as measured by a passive-avoidance task. This impairment was almost completely reversed by merely switching to a standard protein (20% casein) diet on the 10th day after the start of PM. However, the reversal was not observed when the switching to a standard protein regimen was done on the 15th day of the PM diet. Interestingly, the impai...

Hodges JR, Erzinclioglu S, & Patterson K. Evolution of Cognitive Deficits and Conversion to Dementia in Patients with Mild Cognitive Impairment: A Very-Long-Term Follow-Up Study. Dementia and Geriatric Cognitive Disorders. 2006 Apr 4; 21(5-6): 380-391 [Epub ahead of print] MRC Cognition and Brain Sciences Unit, Cambridge, UK. Ten patients with mild cognitive impairment (MCI) underwent extensive neuropsychological evaluation at 12-monthly intervals for a minimum of 6 years. All 10 patients declined and 5 have now died. The onset of dementia, as defined by a fall in global cognitive function (MMSE PMID: 16601329 [PubMed - as supplied by publisher] - Anthony H. Risser | neuroscience | neuropsychology | brain