title: Nitric oxide is necessary for multiple memory processes after learning that a food is inedible in aplysia.
abstract: Nitric oxide (NO) signaling was inhibited via N(omega)-nitro-L-arginine methyl ester (L-NAME) during and after training Aplysia that a food is inedible. Treating animals with L-NAME 10 min before the start of training blocked the formation of three separable memory processes: (1) short-term, (2) intermediate-term, and (3) long-term memory. The treatment also attenuated, but did not block, a fourth memory process, very short-term memory. L-NAME had little or no effect on feeding behavior per se or on most aspects of the animals' behavior while they were being trained, indicating that the substance did not cause a pervasive modulation or poisoning of many aspects of feeding and other behaviors. Application of L-NAME within 1 min after the training had no effect on short- or long-term memory, indicating that NO signaling was not needed during memory consolidation. Treating animals with the NO scavenger 2-phenyl-4,4,5,5-tetramethyl-imidazdine-1-oxy-3-oxide before training also blocked long-term memory. Memory was not blocked by D-NAME, or by the simultaneous treatment with L-NAME and the NO donor S-nitroso-N-acetyl-penicillamine, confirming that the effect of L-NAME is attributable to its effect as a competitive inhibitor of L-arginine for NO synthase in the production of NO rather than to possible effects at other sites. These data indicate that NO signaling during training plays a critical role in the formation of multiple memory processes.
authors.affiliation: Faculty of Life Sciences, Gonda (Goldschmied) Medical Diagnostic Research Center, Bar Ilan University, Ramat Gan 52 900, Israel.
authors.forename: Ayelet
authors.initials: A
authors.lastname: Katzoff
authors.forename: Tziona
authors.initials: T
authors.lastname: Ben-Gedalya
authors.forename: Abraham J
authors.initials: AJ
authors.lastname: Susswein
mesh_terms: D000818:Animals; D001048:Aplysia / Q000187:drug effects / Q000502:physiology*; D003497:Cyclic N-Oxides / Q000494:pharmacology; D003679:Deglutition / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005247:Feeding Behavior / Q000187:drug effects / Q000502:physiology*; D016166:Free Radical Scavengers / Q000494:pharmacology; D007093:Imidazoles / Q000494:pharmacology; D007858:Learning / Q000187:drug effects / Q000502:physiology*; D008568:Memory / Q000187:drug effects / Q000502:physiology; D008570:Memory, Short-Term / Q000187:drug effects / Q000502:physiology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000502:physiology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D010812:Physical Stimulation; D012153:Retention, Psychology / Q000187:drug effects / Q000502:physiology; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D013997:Time Factors
chemical_list: D003497:Cyclic N-Oxides; D004791:Enzyme Inhibitors; D016166:Free Radical Scavengers; D007093:Imidazoles; D020030:Nitric Oxide Donors; C079391:2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester