Effects of an inhibitor of nitric oxide production on memory consolidation and reconsolidation

BOCCIA MM, BLAKE MG, ACOSTA GB, BARATTI CM

Córdoba, 1-3 de Noviembre de 2006

Congreso; XXXVIII Reunión Científica Anual de la Asociación Argentina de Farmacología Experimental (SAFE).; 2006

SAFE

The immediate post-training administration of L-NAME (3-100 mg/kg, ip), a specific inhibitor of the nitric oxide synthase, impaired retention test performance of a one-trial step-through inhibitory avoidance response in adult male CF-1 mice.  Mice that were over-reinforced (1.2 mA, 50 Hz, 1 s) on the learning trial, exhibited a high retention performance 48 h after training. The immediate injection of L-NAME (3-100 mg/kg, ip) after the retention test, that is, after memory reactivation, significantly impaired retention performance over 5 consecutive days. We did not find spontaneous recovery 21 days after training when memory was retrieved 2 days after training and L-NAME was given immediately after it. Additionally, a saving protocol was used in order to examine a potential effect of L-NAME on memory extinction. Although we cannot definitively discard a retrieval deficit, the results obtained are in accordance with the storage deficit interpretation. Retention performance was unchanged in L-NAME - treated mice not undergoing memory reactivation session. These results, taken together, indicate that L-NAME, not only impaired consolidation, but also reconsolidation of an inhibitory avoidance task in mice, suggesting a critical participation of the nitric oxide pathway in both memory processes.