How neuropeptides act within the neural circuits that control social behavior is not well understood. While the prevailing view is that neuropeptides act through synaptic release and then activation o Show more
How neuropeptides act within the neural circuits that control social behavior is not well understood. While the prevailing view is that neuropeptides act through synaptic release and then activation of their canonical receptors on postsynaptic membranes, we investigated the role of a very different form of neuropeptide action in a neural circuit regulating social communication. Specifically, we tested the hypothesis that non-synaptically released oxytocin (OT) can act via the non-canonical receptors vasopressin V1a receptors (V1aR) to regulate social communication in Syrian hamsters. Scent marking, a key form of hamster social communication, can be enhanced by the α-melanocortin stimulating hormone (α-MSH), which stimulates OT but not arginine-vasopressin (AVP) release. Here, we employed hypothalamic injections of α-MSH and the α-MSH MC4R receptor antagonist MCL-0020 to determine the role of α-MSH in the expression of flank marking. To determine if these effects were intracellular calcium (iCa Show less