P488. Divergent Forms of in Vivo Plasticity Between Ventral Hippocampal Inputs and Medial Prefrontal Cortex Microcircuits in a Mouse Model of 22q11.2 Deletion Syndrome

Abstract

Functional connectivity between rodent ventral hippocampus (vHPC) and medial prefrontal cortex (mPFC) supports spatial working memory (SWM) and is disrupted in Df(16)A+/– mice modelling the schizophrenia-predisposing 22q11.2 microdeletion. Inhibition of vHPC-mPFC neural projections or somatostatin-positive (SST+) interneurons in mPFC of wildtype mice impairs vHPC-mPFC connectivity and SWM performance, mimicking phenotypes seen in Df(16)A+/– mice. To examine how functional interactions between these circuit elements contribute to vHPC-mPFC dysconnectivity in Df(16)A+/- mice, and how these interactions may be altered to promote vHPC-mPFC connectivity, we characterized in vivo activity dynamics of discrete mPFC neuronal populations to vHPC-mPFC input activation in wildtype and Df(16)A+/- mice.