Presenter(s): Alyssa Fuentez
Faculty Mentor(s): Angie Michaiel & Cris Niell
Poster 69
Session: Sciences
Visual processing is a vital sense that allows us to interact with the world, yet the mechanisms behind this process remain unknown. Previous research has demonstrated that the thalamus, a midbrain structure, actively regulates information communication to the visual cortex, an area at which attention and decision making occurs. The thalamus is divided into multiple cells called nuclei where first-order nuclei are thought to relay direct sensory information from the outside world to primary cortical areas; whereas, higher-order nuclei are thought to be involved in contextual processing and sensory feedback to higher-order cortical areas. Although research has shown that primary and higher-order thalamic nuclei are involved in visual processing, it has yet to be determined their differential contributions to visual processing. We examined this question by temporarily inactivating primary and higher-order thalamic nuclei separately in six transgenic adult mice that express a fluorescent indicator of neural activity. Visual stimuli were presented and neural activity was monitored using calcium imaging pre and post thalamic nuclei inhibition. Results demonstrated that inhibition of primary thalamic nuclei leads to a minimal increase in visual cortical activity (n=1); whereas, inhibition of higher-order thalamic nuclei resulted in a decrease of both the magnitude and spread of activity (n=1). Results are considered inconclusive due to mistargeting of viral expression observed in four subjects. Additional experiments targeting thalamic nuclei separately are in progress to obtain conclusive results. These studies will lay the foundation for future studies regarding the differential roles of thalamic nuclei in regulating visually guided behaviors.