Oxytocin Receptors Are Expressed by Glutamatergic Prefrontal Cortical Neurons That Selectively Modulate Social Recognition.

ABSTRACT

Social recognition, the ability to recognize individuals that were previously encountered, requires complex integration of sensory inputs with previous experience. Here, we use a variety of approaches to discern how oxytocin-sensitive neurons in the PFC exert descending control over a circuit mediating social recognition in mice. Using male mice with Cre-recombinase directed to the oxytocin receptor gene (Oxtr), we revealed that oxytocin receptors (OXTRs) are expressed on glutamatergic neurons in the PFC, optogenetic stimulation of which elicited activation of neurons residing in several mesolimbic brain structures. Optogenetic stimulation of axons in the BLA arising from OXTR-expressing neurons in the PFC eliminated the ability to distinguish novel from familiar conspecifics, but remarkably, distinguishing between novel and familiar objects was unaffected. These results suggest that an oxytocin-sensitive PFC to BLA circuit is required for social recognition. The implication is that impaired social memory may manifest from dysregulation of this circuit.SIGNIFICANCE STATEMENT Using mice, we demonstrate that optogenetic activation of the neurons in the PFC that express the oxytocin receptor gene (Oxtr) impairs the ability to distinguish between novel and familiar conspecifics, but the ability to distinguish between novel and familiar objects remains intact. Subjects with autism spectrum disorders (ASDs) have difficulty identifying a person based on remembering facial features; however, ASDs and typical subjects perform similarly when remembering objects. In subjects with ASD, viewing the same face increases neural activity in the PFC, which may be analogous to the optogenetic excitation of oxytocin receptor (OXTR) expressing neurons in the PFC that impairs social recognition in mice. The implication is that overactivation of OXTR-expressing neurons in the PFC may contribute to ASD symptomology.