Guest speaker: Teresa Puthussery, Assistant professor of Optometry & Vision Science,
University of California at Berkeley.
Title: A Subcortical Neural Substrate for Reflexive Gaze Stabilization in Primate Retina.
To maintain a stable and clear image of the world, our eyes reflexively follow the direction in which a visual scene is moving. Such gaze stabilization mechanisms reduce image blur as we move in the environment. In non-primate mammals, this behavior is initiated by retinal output neurons called ON-type direction-selective ganglion cells (ON-DSGCs), which detect the direction of image motion and transmit signals to brainstem nuclei that drive compensatory eye movements. However, ON- DSGCs have not yet been functionally identified in primates, raising the possibility that the visual inputs that drive this behavior instead arise from the cortex. In this talk, I will present molecular, morphological, and functional evidence for identification of an ON-DSGC in macaque retina and show evidence of a homologous cell type in human retina. The presence of ON-DSGCs highlights the need to examine the contribution of subcortical retinal mechanisms to normal and aberrant gaze stabilization in the developing and mature visual system. More generally, our findings demonstrate the power of a multimodal approach to study sparsely represented primate RGC types.