http://medicalxpress.com/ en-us Medical Xpress internet news portal provides the latest news on Health and Medicine. (Medical Xpress)—The smooth operation of the brain requires a certain robustness to fluctuations in its home within the body. At the same time, its extraordinary power derives from an activity structure poised at criticality. In other words, it is highly responsive to many low-threshold events. When forced beyond its comfort zone in parameter space—its operating temperature, electrolytes, sugars, blood gas or even sensory input— the direct result is seizure, coma, or both. It would appear that anything rendered too hot or cold, too concentrated or scarce, precipitates seizure. In those genetically predisposed, or compromised by head trauma, the seizing tends toward full-blown epilepsy. A group in Hamburg, led by Michael Frotscher has been chipping away at the causes of common form a epilepsy, temporal lobe epilepsy (TLE). Their latest research published in the journal, Cerebral Cortex, takes a closer at differentiated neurons in the dentate gryus of mouse hippocampus. Once thought to be completely immobilized by virtue of their broadly integrated dendritic trees, these neurons are now shown to become migratory once again in direct response to seizure activity. http://medicalxpress.com/news/2013-03-epilepsy-differentiated-neurons.html Neuroscience Fri, 29 Mar 2013 12:40:19 EST news283779586 Ever find yourself racking your brain on a Monday morning to remember where you put your car keys? When you do find those keys, you can thank the hippocampus, a brain region responsible for storing and retrieving memories of different environments-such as that room where your keys were hiding in an unusual spot. http://medicalxpress.com/news/2013-03-neuroscience-lost-keys.html Neuroscience Thu, 21 Mar 2013 09:26:00 EST news283076722 Columbia University Medical Center (CUMC) researchers have found the first evidence that selective activation of the dentate gyrus, a portion of the hippocampus, can reduce anxiety without affecting learning. The findings suggest that therapies that target this brain region could be used to treat certain anxiety disorders, such as panic disorder and post-traumatic stress syndrome (PTSD), with minimal cognitive side effects. The study, conducted in mice, was published today in the online edition of the journal Neuron. http://medicalxpress.com/news/2013-03-portion-hippocampus-role-modulating-anxiety.html Neuroscience Wed, 06 Mar 2013 12:00:05 EST news281792772 Researchers at the Institute for Comprehensive Medical Science, Fujita Health University and the National Institute for Physiological Sciences, Japan, along with colleagues from 9 other institutions, have identified an exceptional mouse model of schizophrenia. After screening over 160 mutant mouse strains with a systematic battery of behavioral tests, they identified a mutant mouse lacking the Schnurri-2 protein (Shn-2 KO) that exhibits behavioral deficits and other brain features consistent with schizophrenia. Shn-2 is an NF-kappaB site-binding protein that binds enhancers of major histocompatibility complex class I genes and inflammatory cytokines, which harbor common variant single nucleotide polymorphisms associated with schizophrenia. The Shn-2 KO mice display behavioral abnormalities that resemble the symptoms of human schizophrenia, including working memory deficits, impaired nest building behavior (a measure of self-neglect), decreased social behaviors, and anhedonia (loss of the ability to experience pleasure). http://medicalxpress.com/news/2013-02-induction-mild-inflammation-cognitive-deficits.html Psychology & Psychiatry Wed, 06 Feb 2013 09:50:11 EST news279366453 (Medical Xpress)—People with anxiety disorders such as post-traumatic stress disorder (PTSD) often have impaired pattern separation—the process by which similar experiences are transformed into distinct memories. They often react to events that resemble their original trauma, even when in safe situations. http://medicalxpress.com/news/2013-01-medical-center-role-neuron-creation.html Medical research Thu, 24 Jan 2013 08:20:01 EST news278236689 (Medical Xpress)—Neural stem cells in the adult brain boost their levels of lipid metabolism to grow and generate new neurons. This new finding may open novel therapeutic avenues to treat age- or disease-associated loss of brain cells. http://medicalxpress.com/news/2012-12-lipid-metabolism-adult-neural-stem.html Medical research Tue, 04 Dec 2012 06:23:02 EST news273824574 (Medical Xpress)—The brain's two hippocampal formations – one in each hemisphere's temporal lobe, medial to the inferior horn of the lateral ventricle and typically referring to the dentate gyrus, the hippocampus proper (the cornu ammonis), and the subicular cortex – are known to play essential roles in both representing an animal's location and in updating those representations by detecting novelty in the environment. While location representation processes are understood, however, those by which these representations are created and updated have remained elusive. Recently, scientists at University College London have shown that environmental novelty causes the spatial firing patterns of grid cells in the medial entorhinal cortex of freely-moving rodents to expand in scale and reduce in regularity, reverting to their usual scale as the environment again becomes familiar. The researchers conclude that grid expansion provides a potential mechanism for novelty signaling and may enhance the formation of new hippocampal representations, and that the subsequent slow reduction in scale provides a potential familiarity signal. http://medicalxpress.com/news/2012-11-grid-environmental-novelty-hippocampal-patterns.html Neuroscience Wed, 07 Nov 2012 10:50:01 EST news271505979 As is true of many brain structures, the hippocampus, which plays a central role in memory and learning, is made up of multiple cell types organized into domains controlling different functions. Distinct from many other brain regions, however, the hippocampus is a site of active neuronal generation in the adult. Its distinctive pyramidal neurons are contained mainly in the cornu ammonis (CA), while another hippocampal region called the dentate gyrus (DG) is characterized by granule cells. While it is known that the survival of these granule cells relies on the activity of specific transcription factors, how they arise during the differentiation of the hippocampus has remained unknown. http://medicalxpress.com/news/2012-10-transcription-factor-prox1-hippocampal-cellular.html Neuroscience Tue, 16 Oct 2012 08:55:14 EST news269596504 Researchers from the Computational Intelligence Group based at the Universidad Politécnica de Madrid's Facultad de Informática have used machine learning and data mining techniques to compare gene expresssion levels in Alzheimer's disease (AD) patients in two key regions of the hippocampus: the dentate gyrus, where the disease appears to have little or no effect, and the entorhinal cortex, where Alzheimer's disease produces major neuronal damage. http://medicalxpress.com/news/2012-10-intelligence-avenues-alzheimer.html Alzheimer's disease & dementia Tue, 09 Oct 2012 18:38:08 EST news269026672 (Medical Xpress)—Millions of Americans take antidepressants such as Prozac, Effexor, and Paxil, but the explanations for how they work never satisfied René Hen, a professor of psychiatry, neuroscience and pharmacology. http://medicalxpress.com/news/2012-09-chemical-mechanism-antidepressants.html Neuroscience Fri, 21 Sep 2012 08:48:31 EST news267436101 Researchers at the RIKEN-MIT Center for Neural Circuit Genetics have discovered an answer to the long-standing mystery of how brain cells can both remember new memories while also maintaining older ones. http://medicalxpress.com/news/2012-02-memory-formation-triggered-stem-cell.html Neuroscience Thu, 23 Feb 2012 12:56:36 EST news249224191 (Medical Xpress) -- A small team of researchers has found that various forms of child abuse can lead to stunted development in certain regions of the brain. The research carried out by Martin Teicher, Carl Anderson and Ann Polcari, all working in the Boston area, relied on questionnaires and MRI brain scans to determine that certain parts of the hippocampus, all known to be sensitive to stress, were up to six percent smaller in adults who as children had been sexually, verbally or physically abused. The team has published their results in the Proceedings of the National Academy of Sciences. http://medicalxpress.com/news/2012-02-child-abuse-stunted-brain.html Neuroscience Tue, 14 Feb 2012 10:20:49 EST news248437221 Neuron transplants have repaired brain circuitry and substantially normalized function in mice with a brain disorder, an advance indicating that key areas of the mammalian brain are more reparable than was widely believed. http://medicalxpress.com/news/2011-11-rebuild-brain-circuitry.html Neuroscience Thu, 24 Nov 2011 14:00:01 EST news241361994 Memo to mature, health-minded vampires: You might want to consider limiting your treats to victims under age 30. http://medicalxpress.com/news/2011-08-scientists-blood-factors-aging-brains.html Medical research Wed, 31 Aug 2011 13:36:06 EST news234016547 Scientists have known for years that neurogenesis takes place throughout adulthood in the hippocampus of the mammalian brain. Now Columbia researchers have found that under stressful conditions, neural stem cells in the adult hippocampus can produce not only neurons, but also new stem cells. The brain stockpiles the neural stem cells, which later may produce neurons when conditions become favorable. This response to environmental conditions represents a novel form of brain plasticity. The findings were published online in Neuron on June 9, 2011. http://medicalxpress.com/news/2011-06-brain-environmental.html Neuroscience Mon, 13 Jun 2011 13:11:14 EST news227188831 New neurons take more than six months to mature in adult monkeys and that time is likely even longer in humans, according to researchers at the University of Pittsburgh School of Medicine, the University of Illinois, and Pennsylvania State University. Their findings, reported this week in the online version of the Proceedings of the National Academy of Sciences, challenge the notion that the time it takes for neurogenesis is the reason anti-depressant medications are not fully effective until three to five weeks after treatment begins. http://medicalxpress.com/news/2011-06-neurons-months-mature-non-human-primate.html Medical research Mon, 06 Jun 2011 15:44:02 EST news226593819