Comparison of the amnestic effects of NMDA receptor antagonist MK-801 and nitric oxide synthase inhibitors: L-NAME and L-NOARG in goldfish.
Investigations indicate that the induction of long-term potentiation (LTP) may be mediated by postsynaptic N-methyl-D-aspartate (NMDA) receptors and that the maintenance of LTP may be initiated by nitric oxide (NO), a retrograde messenger carrying signals backward from the postsynaptic to the presynaptic neuron. The present study compared amnestic effects of dizocilpine maleate (MK-801), an NMDA receptor antagonist, and nitro-L-arginine-methyl-ester (L-NAME) and N-nitro-L-arginine (L-NOARG), nitric oxide (NO) inhibitors, in goldfish, using active-avoidance conditioning as the learning paradigm. The results showed that MK-801 and NO inhibitors produced anterograde amnesia at doses that did not impair performance processes necessary for learning to occur. Furthermore, MK-801 did not produce retrograde amnesia, whereas L-NAME did, suggesting that MK-801 impaired learning whereas NO inhibitors impaired memory consolidation and possibly also learning.
Xu
X
X
Department of Psychology, Grand Valley State University, Allendale, Michigan 49401, USA. xux@gvsu.edu
Boshoven
W
W
Lombardo
B
B
Spranger
J
J
D000647:Amnesia / Q000139:chemically induced; D000704:Analysis of Variance; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D016291:Dizocilpine Maleate / Q000494:pharmacology; D004597:Electroshock; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology*; D006054:Goldfish; D017774:Long-Term Potentiation / Q000502:physiology; D008568:Memory / Q000187:drug effects*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D019335:Nitroarginine / Q000494:pharmacology; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors* / Q000502:physiology; D013997:Time Factors
D004791:Enzyme Inhibitors; D018691:Excitatory Amino Acid Antagonists; D016194:Receptors, N-Methyl-D-Aspartate; D019335:Nitroarginine; D016291:Dizocilpine Maleate; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester