Effects of intrahippocampal L-NAME treatment on the behavioral long-term potentiation in dentate gyrus

Using a combination of electrophysiological recordings, behavioral tests and local pharmacological administration in hippocampus, we investigated in the present study the effects of nitric oxide (NO) synthase inhibitor N-nitro-L-arginine methyl ester (L-NAME) on the behavioral long-term potentiation (LIP) and maze learning performance in freely moving rats. The results showed as follows: (1) intrahippocampal L-NAME administration led to a defect in maze learning performance of the animals; (2) L-NAME treatment also substantially impaired the induction of the behavioral LTP in perforant pathway to dentate gyrus (PP-DG) pathway induced by maze learning task, while it had no significant effects on basic synaptic transmission in PP-DG pathway; Collectively, these results indicate that NO synthesis may be critical for the behavioral LTP in PP-DG pathway and maze learning performance. (C) 2012 Elsevier Ireland Ltd. All rights reserved.