Functional roles of arg-vasopressin and oxytocin on cellular excitability in neurons of the rat lateral amygdala.
The amygdala is a critical part of the limbic system with important roles in social behavior. Abnormal activity in the lateral amygdala nucleus (LA) has been implicated in several disorders, including autism spectrum disorder (ASD) in which abnormal social functioning is a primary symptom. The peptide hormones arginine-vasopressin (AVP) and oxytocin (OT) are strongly implicated in social behavior, and may also be involved in the pathophysiology of ASD. AVP and OT increase excitatory responses in the brain, however their role in the LA is unknown. Here, the effects of AVP and OT on membrane properties of LA neurons were investigated using whole-cell recording of LA neurons in vitro. AVP decreased accommodation and hyperpolarization-activated current (Ih) in LA pyramidal cells, resulting in increased excitability. OT increased action potential accommodation and Ih resulting in decreased excitability. These results suggest AVP and OT may modulate social behavior by controlling excitability in the amygdala.