http://medicalxpress.com/ en-us Medical Xpress internet news portal provides the latest news on Health and Medicine. How do organisms evolve into individuals that are distinguished from others by their own personal brain structure and behavior? Scientists in Dresden, Berlin, Münster, and Saarbrücken have now taken a decisive step towards clarifying this question. Using mice as an animal model, they were able to show that individual experiences influence the development of new neurons, leading to measurable changes in the brain. The results of this study are published in Science on May 10, 2013. http://medicalxpress.com/news/2013-05-individuality-growth-brain-cells.html Neuroscience Thu, 09 May 2013 14:00:05 EST news287313261 Three myths about sleepwalking – sleepwalkers have no memory of their actions, sleepwalkers' behaviour is without motivation, and sleepwalking has no daytime impact – are dispelled in a recent study led by Antonio Zadra of the University of Montreal and its affiliated Sacré-Coeur Hospital. Working from numerous studies over the last 15 years at the hospital's Centre for Advanced Studies in Sleep Medicine at the Hôpital du Sacré-Cœur de Montréal and a thorough analysis of the literature, Zadra and his colleagues have raised the veil on sleepwalking and clarified the diagnostic criteria for researchers and clinicians. http://medicalxpress.com/news/2013-03-sleepwalkers-theyve.html Neuroscience Thu, 14 Mar 2013 04:45:56 EST news282455141 French police investigating a series of rapes in the southern city of Marseille are confounded after tracing DNA evidence to a set of twins but not knowing which one may be to blame. http://medicalxpress.com/news/2013-02-french-police-confounded-twins-dna.html Genetics Sun, 10 Feb 2013 11:10:04 EST news279716991 (Medical Xpress)—Researchers at the University of Iowa have found that three volunteer women with defective amygdalas were able to experience internal fear. In their paper published in the journal Nature Neuroscience, the team describes how they were able to induce fear in the volunteers despite all three suffering from a degenerative disease that made them immune to fear in the "normal" sense. http://medicalxpress.com/news/2013-02-amygdala.html Neuroscience Mon, 04 Feb 2013 06:09:15 EST news279180321 An international team, led by researchers from the University of California, San Diego School of Medicine, has discovered that "random" mutations in the genome are not quite so random after all. Their study, to be published in the journal Cell on December 21, shows that the DNA sequence in some regions of the human genome is quite volatile and can mutate ten times more frequently than the rest of the genome. Genes that are linked to autism and a variety of other disorders have a particularly strong tendency to mutate. http://medicalxpress.com/news/2012-12-genomic-hotspots-clues-autism-disorders.html Genetics Thu, 20 Dec 2012 12:00:32 EST news275227217 (Medical Xpress)—European researchers have discovered that five genes play a key role in determining human facial shapes. Presented in the journal PLoS Genetics, the genome-wide association study on facial phenotype can help scientists identify more genes for other complex human phenotypes, including height. http://medicalxpress.com/news/2012-10-scientists-genes-facial.html Genetics Thu, 11 Oct 2012 07:20:36 EST news269158673 Genetics may make some women more vulnerable to the pressure of being thin, a study published in the International Journal of Eating Disorders has found. From size-zero models to airbrushed film stars, thinness is portrayed as equaling beauty across Western culture, and it's an ideal often cited as a cause of eating disorder symptoms in young women. http://medicalxpress.com/news/2012-10-women-genes-pressure-thin.html Psychology & Psychiatry Wed, 03 Oct 2012 00:00:02 EST news268408283 (Medical Xpress)—A new twin study from the Norwegian Institute of Public Health shows that the heritability of avoidant and dependent personality disorder traits might be higher than previously reported. People with avoidant personality disorder are often anxious in the company of others, while people with dependent personality disorder feel more secure. http://medicalxpress.com/news/2012-09-heritability-personality-disorder-traits.html Psychology & Psychiatry Mon, 24 Sep 2012 10:34:16 EST news267701649 Fainting has a strong genetic predisposition, according to new research published in the August 7, 2012, print issue of Neurology, the medical journal of the American Academy of Neurology. Fainting, also called vasovagal syncope, is a brief loss of consciousness when your body reacts to certain triggers, such as emotional distress or the sight of blood. http://medicalxpress.com/news/2012-08-fainting-family.html Neuroscience Mon, 06 Aug 2012 16:03:00 EST news263487682 Your genes determine much about you, but environment can have a strong influence on your genes even before birth, with consequences that can last a lifetime. In a study published online in Genome Research, researchers have for the first time shown that the environment experienced in the womb defines the newborn epigenetic profile, the chemical modifications to DNA we are born with, that could have implications for disease risk later in life. http://medicalxpress.com/news/2012-07-differences-human-twins-birth-highlight.html Genetics Sun, 15 Jul 2012 17:00:01 EST news261572668 Aside from identical twins, no two individuals are completely identical genetically. Most differences between individuals are due to single nucleotide changes or polymorphisms (SNPs) – DNA sequence variations – in the genome. http://medicalxpress.com/news/2012-05-people-propensity-disease.html Genetics Mon, 14 May 2012 13:57:17 EST news256222630 Gene scans for everyone? Not so fast. New research suggests that for the average person, decoding your own DNA may not turn out to be a really useful crystal ball for future health. http://medicalxpress.com/news/2012-04-gene-fast.html Genetics Mon, 02 Apr 2012 12:47:19 EST news252589619 Parents may be misinformed during prenatal scans on whether their twins are identical or non-identical, say UCL researchers in a new commentary piece published today in BJOG: An International Journal of Obstetrics and Gynaecology. http://medicalxpress.com/news/2012-02-twins-identical.html Obstetrics & gynaecology Wed, 29 Feb 2012 05:03:03 EST news249714176 Although the genetic basis of autism is now well established, a growing body of research also suggests that environmental factors may play a role in this serious developmental disorder affecting nearly one in 100 children. Using a unique study design, a new study suggests that low birth weight is an important environmental factor contributing to the risk of autism spectrum disorder (ASD). http://medicalxpress.com/news/2012-01-birth-weight-role-autism-spectrum.html Autism spectrum disorders Thu, 19 Jan 2012 14:13:01 EST news246204771 A new study of twins led by the University of Colorado Boulder shows that today's smokers are more strongly influenced by genetic factors than in the past and that the influence makes it more difficult for them to quit. http://medicalxpress.com/news/2011-11-twins-genetic-factors.html Health Wed, 16 Nov 2011 10:41:38 EST news240662492 A new research report contributes to the increasing evidence that repeated occupational exposure to certain chemical solvents raises the risk for Parkinson's disease. Researchers analyzed the occupational histories of twins in which one of the pair developed the neurodegenerative disorder, and assessed that twin's likelihood of exposure to six chemicals previously linked to Parkinson's. Of the six chemicals investigated, researchers concluded that two common chemical solvents, trichloroethylene (TCE) and perchloroethylene (PERC), are significantly linked to development of this disease. This study, supported in part by the National Institute of Neurological Disorders and Stroke (NINDS), a part of the National Institutes of Health, appears in the Nov. 14, 2011 issue of Annals of Neurology. http://medicalxpress.com/news/2011-11-twin-occupational-chemical-exposure-linked.html Parkinson's & Movement disorders Mon, 14 Nov 2011 04:15:36 EST news240466526 Identical twins have identical genomes, but that is where it stops. There are subtle differences in their personalities, how they look, how they act and in their susceptibility to disease. How can this be? http://medicalxpress.com/news/2011-10-identical-twins.html Medical research Fri, 14 Oct 2011 11:33:41 EST news237810812 People prefer to make friends with others who share their beliefs, values, and interests. The more choice people have, the more their friends are alike, according to research published in Group Processes and Intergroup Relations. http://medicalxpress.com/news/2011-09-choice-friends-similar-closer.html Psychology & Psychiatry Thu, 22 Sep 2011 10:07:59 EST news235904852 Like DNA, fingerprints are unique to each person or set of identical twins. That makes them a valuable identification tool for everything from crime detection to international travel. But what happens when the tips of our fingers are missing those distinctive patterns of ridges? http://medicalxpress.com/news/2011-09-genetic-defect-fingerprints.html Genetics Mon, 19 Sep 2011 03:11:37 EST news235620685 Eating a diet high in vitamin D, as well as the nutrients betaine and methionine, might help reduce the risk of macular degeneration, according to new research conducted by Tufts Medical Center scientists. Their study of identical twins from the US World War II Twin Registry also found that the more a person smoked, the higher their risk of developing macular degeneration. The study, "Smoking, Dietary Betaine, Methionine, and Vitamin D in Monozygotic Twins with Discordant Macular Degeneration: Epigenetic Implications" published in the journal Ophthalmology on July 1, is the first to look at identical twin pairs in which one twin had early age-related macular degeneration (AMD), and the other had late stage AMD. http://medicalxpress.com/news/2011-07-twin-lifestyle-diet-significantly-macular.html Health Tue, 05 Jul 2011 17:12:57 EST news229104757 A new paper by University of Calgary psychologist Dr. David Hodgins says the proliferation of gambling opportunities around the world, particularly online, is increasing the visibility of gambling disorders and giving access to people who previously had no exposure to gambling opportunities. http://medicalxpress.com/news/2011-05-gambling-problem-exposed-access.html Psychology & Psychiatry Thu, 19 May 2011 03:57:00 EST news224996197