Ofer Yizhar, Associate Professor, Dept. of Brain Sciences, Weizmann Institute of Science, Israel
Title: Optogenetic dissection of local and long-range connections in prefrontal circuits
The prefrontal cortex (PFC) plays an important role in regulating social functions in mammals, and impairments in this region have been linked with social dysfunction in psychiatric disorders. The PFC plays a part in multiple brain-wide networks regulating behavior, and its long-range connections to different cortical and subcortical targets are thought to be involved in distinct behavioral functions. How is information about the multitude of cognitive/behavioral processes routed into and out of the PFC circuit? We are interested in understanding how PFC microcircuits process behavioral information, and how distinct PFC output neuron populations regulate learning, decision-making and social behavior.
I will first describe a set of experiments aimed at understanding the structure of synaptic connectivity among amygdala-projecting neurons in the mPFC. Using single-neuron two-photon optogenetic stimulation and imaging, we demonstrated that these neurons show unique layer-specific connectivity features compared with randomly-sampled mPFC neurons. I will then describe our efforts to engineer new optogenetic tools for silencing of long-range axonal projections between brain regions. To efficiently suppress synaptic transmission, we engineered a new set of bistable rhodopsins that selectively couple to the Gi/o signaling pathway and can be used to suppress synaptic release in vitro and in vivo, in a spatially and temporally-precise manner.