Professor Emeritus, Department of Psychology
Ph.D. University of Michigan
M.S. University of Washington
B.S. University of Washington
Research Interests: Cognitive-Neuroscience; Neural mechanisms and structures underlying selective attention
Overview: Michael Posner is Professor Emeritus at the University of Oregon and Adjunct Professor at the Weill Medical College in New York (Sackler Institute).
Dr. Posner's current work deals with genetic and experiential factors in the development of brain networks underlying attention and learning. We are currently examining how changes in white matter might contribute to improved performance. In one study conducted together with the Niell lab we are imposing a theta rhythm on cells in the anterior cingulate of the mouse and examining whether the resultant activity leads to improved myelination in pathways near the cingulate. We are also examining if epigenetic factors related to methylation might account for individual differences in this process.
Changes in white matter in mice resulting from low-frequency brain stimulation.
Proc Natl Acad Sci U S A. 2018 Jun 18;:
Authors: Piscopo DM, Weible AP, Rothbart MK, Posner MI, Niell CM
Recent reports have begun to elucidate mechanisms by which learning and experience produce white matter changes in the brain. We previously reported changes in white matter surrounding the anterior cingulate cortex in humans after 2-4 weeks of meditation training. We further found that low-frequency optogenetic stimulation of the anterior cingulate in mice increased time spent in the light in a light/dark box paradigm, suggesting decreased anxiety similar to what is observed following meditation training. Here, we investigated the impact of this stimulation at the cellular level. We found that laser stimulation in the range of 1-8 Hz results in changes to subcortical white matter projection fibers in the corpus callosum. Specifically, stimulation resulted in increased oligodendrocyte proliferation, accompanied by a decrease in the g-ratio within the corpus callosum underlying the anterior cingulate cortex. These results suggest that low-frequency stimulation can result in activity-dependent remodeling of myelin, giving rise to enhanced connectivity and altered behavior.
PMID: 29915074 [PubMed - as supplied by publisher]