Molsidomine antagonizes L-NAME-induced acquisition deficits in a recognition memory task in the rat

The present study was designed to investigate the role of nitric oxide (NO) on the acquisition of a recognition memory task in the rat. For this purpose, the effects on memory exerted by pre-training administration of the NO synthase inhibitor L-NAME (Nω-nitro-L-arginine methyl ester) and the NO donor molsidomine (N-[ethoxycarbonyl]-3-[4-morpholinosydnomine]) were assessed by using the object recognition task, a working memory paradigm based on the differential exploration of a new and familiar object. In a first dose-response study, it was found that L-NAME (10, 30, and 60mgkg-1, i.p.) at 30 but not at 10mgkg-1 disrupted animals performance, whereas the dose of 60mgkg-1 induced side effects. Molsidomine (2 and 4mgkg-1, i.p.) at 4 but not at 2mgkg-1, antagonized the L-NAME-induced performance deficits. These results indicate that NO is involved in the acquisition of a recognition memory task.