title: An inhibitor of nitric oxide synthesis prevents memory formation in the chick.
abstract: Memory formation is presumed to require retrograde communication across synaptic junctions. Nitric oxide (NO) is a putative retrograde messenger at N-methyl-D-aspartate (NMDA)-mediated synapses [8, 9]. Inhibitors of nitric oxide synthesis block initiation of long-term potentiation [2, 3, 19]. Memory for a one-trial passive avoidance task in the young chick involves an NMDA-linked intracellular cascade culminating in lasting modulation of synaptic morphology and [6, 18]. Here we show that injection of the nitric oxide synthase inhibitor N-nitro-L-arginine prior to training results in amnesia for the passive avoidance task; the amnesia can be overcome by injecting L-arginine along with the inhibitor. Thus we have verified for the first time experimentally that NO plays a role in memory formation.
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000037:antagonists & inhibitors; D000647:Amnesia / Q000139:chemically induced; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D001362:Avoidance Learning / Q000187:drug effects; D002645:Chickens; D008568:Memory / Q000187:drug effects*; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase; D019335:Nitroarginine
chemical_list: D019335:Nitroarginine; D009569:Nitric Oxide; D001120:Arginine; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases