Bombesin/gastrin-releasing peptide receptors in the basolateral amygdala regulate memory consolidation

Several receptor and intracellular signalling systems in the basolateral amygdala (BLA) regulate memory formation. In the present study, we show that bombesin/gastrin-releasing peptide (GRP) receptors in the BLA are involved in the consolidation of affectively motivated memory. Adult male rats were trained in a single-trial step-down inhibitory avoidance task and tested for retention 24 h later. Post-training systemic injection of the bombesin/GRP receptor antagonist (D-Tpi6, Leu13 psi[CH2NH]-Leu14) bombesin (6-14) (RC-3095) impaired memory retention. In rats implanted under thionembutal anaesthesia with guide cannulae aimed at the BLA, post-training bilateral infusion of RC-3095 into the BLA dose-dependently impaired retention. Pre-training unilateral muscimol inactivation of the BLA blocked the memory-impairing effect of post-training systemic administration of RC-3095. The results suggest that bombesin/GRP receptors in the BLA are involved in the consolidation of aversive memory, and the BLA mediates the memory-impairing effect of systemic bombesin/GRP receptor blockade.