β-Adrenergic receptors in the insular cortex are differentially involved in aversive vs. incidental context memory formation.

The goal of this research was to determine the effects of β-adrenergic antagonism in the IC before or after inhibitory avoidance (IA) training or context pre-exposure in a latent inhibition protocol. Pretraining intra-IC infusion of the β-adrenergic antagonist propranolol disrupted subsequent IA retention and impaired latent inhibition of IA, but had no effect on formation of memory for an inert context (termed incidental memory). These results indicate that IC β-adrenergic receptors are necessary for memory acquisition of an aversive, but not an inconsequential, context. Nevertheless, subsequent association of a familiar and hitherto inconsequential context with an unconditioned stimulus (US) does require activation of these receptors during its initial acquisition.