Inhibition of nitric oxide synthase does not impair spatial learning

摘要: Nitric oxide (NO), a putative intercellular messenger in the CNS, may be involved certain forms of synaptic plasticity and learning. This article reports series experiments investigating effects N omega-nitro-L-arginine methyl ester (L-NAME) upon various learning memory watermaze. L-NAME (75 mg/kg, i.p., sufficient to bring about > 90% inhibition NO synthesis brain) produced an apparent impairment spatial when given naive rats during acquisition (3 d, six training trials per day). was dose related, stereoselective, attenuated by coadministration L-arginine. A second study showed that did not affect retention previously learned task. In addition, visual discrimination task, rate at which criterion levels performance were reached unaffected L-NAME. Thus, synthase cause selective without effect retention. However, analysis early task revealed significantly elevated escape latencies L-NAME-treated rats, suggesting have more general effects. As normal learn very rapidly, possibility arises deficit is due disruption some process other than se. further investigated this possibility. found impair new platform position same environment. Surprisingly, also had no on watermaze located novel environment well practiced with all aspects training. Finally, trained just one trial day. systemic injection inhibitor impairs behavioral two tasks their initial acquisition, but basis functional unlikely any direct mechanisms