The endocannabinoid system plays a major role in modulating memory. In the present study, we examined whether cannabinoid agonists influence the consolidation of stimulus-response/habit memory, a form of memory dependent upon the dorsolateral striatum (DLS). In experiment 1, rats were trained in a cued platform water maze task in which animals were released from different start points and in order to escape had to find a cued platform which was moved to various spatial locations across trials. Immediately following training, rats received an i.p. injection of the cannabinoid receptor agonist WIN 55, 212-2 (1mg/kg or 3mg/kg) or a vehicle solution. In experiment 2, rats were trained in a forced-response version of the water plus-maze task in which a consistent body-turn response was reinforced across trials. Immediately following training, rats received an i.p. injection of WIN 55,212-2 (3mg/kg) or vehicle. In experiment 3, rats were trained in the cued platform task and after training received bilateral intra-DLS WIN 55,212-2 (100ng/.5μL or 200ng/.5μL) or vehicle. In experiments 1-3, the higher doses of WIN 55,212-2 were associated with significant memory impairments, relative to vehicle-treated controls. The results indicate that peripheral or intra-DLS administration of a cannabinoid receptor agonist impairs consolidation of DLS-dependent memory. The findings are discussed within the context of previous research encompassing cannabinoids and DLS-dependent learning and memory processes, and the possibility thatcannabinoids may be used to treat some habit-like human psychopathologies (e.g. posttraumatic stress disorder) is considered.
Copyright © 2014. Published by Elsevier Ltd.

PMID:

 

24838065

 

[PubMed – as supplied by publisher]