In Person Seminar: Brainstem Serotonin Neurons Selectively Gate Retinal Information Flow to Thalamus

About this Seminar

In this talk, Dr. Andermann will describe his lab's recent studies testing the hypothesis that neuromodulators might efficiently determine which visual information streams reach the cortex, by selective gating of transmission at specific retinal ganglion cell (RGC) axons in the thalamus. The lab found that optogenetic stimulation of serotonergic axons in visual thalamus of awake mice suppressed calcium activity and glutamate release in RGC boutons. Two-photon calcium imaging revealed that serotonin axon stimulation suppressed RGC boutons preferring global changes in luminance more than those preferring local visual stimuli, while the converse was true for suppression induced by increases in arousal. Convergent evidence from brain slice electrophysiology, immunohistochemistry, single cell sequencing and retinal electrophysiology indicates that presynaptic 5-HT1B receptors are enriched in RGC boutons preferring global luminance changes. Together, these data suggest a mechanism by which brainstem serotonin axons differentially suppress specific streams of visual information before they reach thalamocortical neurons.

Additional Details

This is a free event hosted by the Fralin Biomedical Research Institute and co-sponsored by the institute's Center for Neurobiology Research. The Pioneers in Biomedical Research Seminar Series, which runs annually from September to May, has featured leading biomedical researchers from throughout the country since the program began in 2012. The lectures are also open to all members of the Virginia Tech community including graduate students, undergraduates, faculty, and staff, as well as the public.

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