Thalamocortical Visual Processing

National Eye Institute

Investigators

Abstract

During the current fiscal year, we have made progress in all four major research projects within the lab. Current research questions include: Research Project 1. How do reciprocal circuits connecting the visual thalamus and visual cortex contribute to visual discrimination and attention and are these circuits disrupted in attention deficit disorder and/or autism? Research Project 2. How does activity in thalamo-cortico-thalamic circuits mediate training-induced vision recovery following visual cortical stroke? Research Project 3. What alterations in retino-thalamo-cortical circuit structure and function generate visual deficits observed in schizophrenia? Research Project 4. How do early visual circuits incorporate contextual information during active, natural vision? Toward Project 1, we collected data in two major experiments, both involving simultaneous recordings in multiple visual cortical areas and one experiment including optogenetic manipulation of feedback communication. Data analyses toward both of these experiments is currently ongoing, currently at the spike sorting stage. We are building new automated sorting approaches to complement manual sorting and will plan to apply rigorous statistical modeling to the data once pre-processed. This project is in collaboration with Dr. Adam Snyder at the University of Rochester. A paper describing preliminary results and methods associated with this project was published this year. Also toward Project 1, we published a landmark study in which we optogenetically modulated cortical feedback to the visual thalamus, showing stream-specific effects of feedback on spatial precision, in addition to global effects of feedback on temporal precision. We aim to examine our newly collected corticocortical data for similar effects. Toward Project 2, we continue to obtain anatomical and behavioral data in our novel model of vision recovery following stroke. This project is a collaboration with Drs. Krystel Huxlin (U. Rochester) and Kristina Nielsen (Johns Hopkins University). Toward Project 3, we continue to test the novel hypothesis that inflammation in the early visual system leads to visual deficits associated with schizophrenia. Work with subjects is ongoing. Electrophysiological and anatomical preliminary data have been collected and are currently under analyses. A paper describing changes in the visual pathways following damage to the retina was recently published. Toward Project 4, we have collected and pre-processed electrophysiological data that we have shared with our theoretical collaborator, Dr. Dan Butts at U. Maryland. Ongoing analyses and modeling are currently underway.