CB1 receptors (McDonald et al., 2008). It is interesting to speculate that downregulation of cannabinoid receptors observed here in socially-isolated rats is associated with increased endocannabinoid signaling; such changes would be expected to modify GABA-ergic and glutamatergic inputs to oxytocin neurons in the supraoptic nucleus and, ultimately, regulate oxytocin release. Long-lasting dysregulation in the endocannabinoid system in the supraoptic nucleus may, therefore, contribute to the perturbed social behavior of isolates (if the loss of these receptors are on inhibitory neurons) or represent a compensatory mechanism (if the loss of these receptors are on excitatory neurons) exhibited in the brains of isolates.
