Modulation of prefrontal cortex excitation/inhibition balance rescues social behavior in <i>CNTNAP2</i>-deficient mice.

Abstract

Alterations in the balance between neuronal excitation and inhibition (E:I balance) have been implicated in the neural circuit activity-based processes that contribute to autism phenotypes. We investigated whether acutely reducing E:I balance in mouse brain could correct deficits in social behavior. We used mice lacking the <i>CNTNAP2</i> gene, which has been implicated in autism, and achieved a temporally precise reduction in E:I balance in the medial prefrontal cortex (mPFC) either by optogenetically increasing the excitability of inhibitory parvalbumin (PV) neurons or decreasing the excitability of excitatory pyramidal neurons. Surprisingly, both of these distinct, real-time, and reversible optogenetic modulations acutely rescued deficits in social behavior and hyperactivity in adult mice lacking <i>CNTNAP2</i> Using fiber photometry, we discovered that native mPFC PV neuronal activity differed between <i>CNTNAP2</i> knockout and wild-type mice. During social interactions with other mice, PV neuron activity increased in wild-type mice compared to interactions with a novel object, whereas this difference was not observed in <i>CNTNAP2</i> knockout mice. Together, these results suggest that real-time modulation of E:I balance in the mouse prefrontal cortex can rescue social behavior deficits reminiscent of autism phenotypes.