Deficient spatial memory induced by blockade of beta-adrenoceptors in the hippocampal CA1 region

A previous study showed that intra-CAl infusion of the beta-adrenergic antagonist DL-propranolol interfered with consolidation of memory for contextual fear conditioning (J.-Z. Ji, X.-M. Wang, & B.-M. Li, 2003). The present study investigated the effect of similarly administered DL-propranolol on consolidation of spatial memory for the water maze. DL-propranolol infused 5 min, but not 6 hr, posttraining caused a deficit in 48-hr memory for the spatial water maze task, whereas similarly administered D-propranolol, which has an equipotent "local-anesthetic" activity but significantly lower beta-blocking activity, induced no amnesia. However, DL-propranolol administered 5 min posttraining did not impair 48-hr memory for the cued water maze task. Thus, beta-adrenoceptor in area CA1 is involved in regulating consolidation of spatial memory for the water maze.