Vanderbilt neuroscience research featured at annual conference in Washington, D.C.
Vanderbilt researchers from across the campus and medical center shared their new and ongoing research with colleagues from around the world in over 150 presentations and posters at the annual Society for Neuroscience conference in Washington, D.C. Nov. 15-19.
Research presented by Vanderbilt faculty, students and staff researchers spanned the neuroscience field, ranging from the role of individual neurons in responding to pain to how sensory cues may prolong addiction.
Examples of the research are below. For a full listing of all Vanderbilt research presented at the conference, search the conference program for “Vanderbilt” at http://www.sfn.org/am2008.
Smokers' brains drawn to cigarettes even if they've just had a smoke
Though the major role of nicotine in smoking addiction is widely established, recent studies have noted the significance of sensory cues, such as photos or video of smoking, in the continuation of smoking habits. New research by David Zald, associate professor of psychology and Vanderbilt Kennedy Center investigator, and colleagues at the VA Medical Center in Minneapolis and the University of Minnesota, indicates that an area of smokers' brains called the insula, viewed using the brain scanning technology positron emission topography or PET, responded more strongly when an individual saw images of smoking and cigarettes than it did when the person was shown basic pleasant images, even after the person had been injected with nicotine. This is the same area that activates when a smoker is craving a cigarette. The insula is a current focus in addiction research due to recent findings that heavy smokers who had suffered a stroke in that area immediately stopped smoking. The new findings highlight this brain area's role in smokers' response to cigarette-craving cues, regardless of nicotine withdrawal or satiety.
Evidence of connection between meditation and emotional control found in brain
Despite growing interest in meditation and mind-body practices, questions remain regarding what is happening in the brain during meditation. Department of Psychology graduate student Michael Treadway, Research Assistant Professor of Radiology Baxter Rogers, and colleagues at several medical centers in Massachusetts and Minneapolis used functional magnetic resonance imaging or fMRI to examine the right anterior insula, a brain area previously shown to be active during meditation, while experienced meditators were meditating and while they were resting. They found increased activity in that area during meditation in these individuals, as well as more connective activity with brain areas shown to be involved in emotion regulation. The findings offer potential evidence that meditation does impact and influence the brain's hard wiring over time and may help dedicated practitioners better regulate their emotions.
Brain area that may be responsible for processing painful heat found
Specific brain areas are involved in processing pain from heat as opposed to other touch stimuli, new research has found. Using fMRI, Li Min Chen, assistant professor at the Vanderbilt University Institute of Imaging Science, and colleagues at the institute and the Department of Psychology were able for the first time to pinpoint those specific nuclei that process painful heat as opposed to innocuous touch – the difference between touching a cold and hot stove, for instance. Identification of the neurons processing this type of stimuli was not possible in the past using traditional MRI scans. The findings show several brain regions are involved in processing pain, with some linked directly to heat pain, and offer new insights into how the brain processes pain overall.
Psychopathic personality disorder may be linked to how brain processes reward and motivation
Psychopathy is a personality disorder characterized by persistent antisocial behavior, blunted empathy and moral sensitivity, and impaired decision-making. Joshua Buckholtz, a graduate student in the Department of Psychology, Treadway, and their Vanderbilt colleagues used fMRI to examine brain activity in volunteers during a task where they anticipated receiving a monetary reward. They found that the “reward circuits” in volunteers who had been determined to have some psychopathic traits responded differently than their counterparts without the traits, particularly when they were anticipating winning or losing a reward. They found that those with the traits responded more strongly to anticipating the reward and less strongly to receiving it. A disruption in this balance may underlie elevated aggression, impaired decision-making and increased risk-taking in psychopathy.
Specific impacts of prenatal cocaine exposure on cortical development identified
New research by Barbara Thompson, a research fellow in the Pharmacology Department and colleagues at the Vanderbilt Kennedy Center and the Department of Neurology, sheds additional light on the specific impacts of cocaine use by a pregnant mother on her developing fetus. The new work follows previous research by the team that demonstrated permanent behavioral, morphological and cellular changes following prenatal cocaine exposure. In the new study, Thompson and her colleagues found differences in how the brain of rabbits prenatally exposed to cocaine responded to dopamine compared to control subjects, and identified the specific groups of neurons responsible for the differences. The results suggest long-term functional consequences within these groups of neurons as a result of prenatal cocaine exposure.
Unraveling the molecular mechanism of amphetamine action
Abused drugs including amphetamine pose a serious hazard to public health, and understanding how they interact with the body and brain on a molecular level is critical to developing effective treatments for their abuse. Lucia Carvelli, a research assistant professor in the Pharmacology Department, and her Vanderbilt colleagues have developed a model using worms that have been genetically modified to prevent proper dopamine processing. The model illuminates the role dopamine processing plays in amphetamine’s effects. It can be used for studying amphetamine’s effects at the molecular level, and also provides additional information about the role specific genes, DAT-1, a dopamine transporter, and DOP, a dopamine receptor, play in amphetamine’s impact on behavior, opening new doors for future treatments.
Link between early sensory deprivation and future sensory experience explained
Sensory deprivation beginning near birth is known to degrade the function of the neurons responsible for processing information about what we see, touch, taste, hear and smell to the point that the brain cannot detect subtle differences in texture. The cause of this problem was not understood. Ford Ebner, professor of psychology and Vanderbilt Kennedy Center investigator, and his colleagues in the Department of Psychology found sensory experience early in life produces synchrony among neuron assemblies in a brain area known as the barrel cortex. Sensory deprivation prevents this synchrony from happening, which leads to the perception problems seen later in life.
Using fMRI to understand anxiety and empathy in Williams Syndrome
Williams Syndrome is a neurodevelopmental disorder marked by hypersociability, decreased fear of strangers and heightened empathy, along with anxiety and fears not related to social interaction. Vanderbilt Kennedy Center investigator Tricia Thornton-Wells and her colleagues at the Kennedy Center and the Vanderbilt University Institute of Imaging Sciences have used fMRI to determine how differences in certain brain areas, specifically the amygdala, may explain some of the anxiety people with Williams syndrome experience, and differences in how their posterior cortex processes emotional images might explain why these individuals are often more empathetic than others. The findings also offer insights about the typical development of empathy, with implications for other disorders, such as autism and schizophrenia, in which it is disrupted.
Contact: Melanie Moran, (615) 322-NEWS