Effects of 7-nitroindazole on long-term potentiation induced by l-clausenamide and high-frequency stimulation in rat hippocampus in vivo.
OBJECTIVE
To study the antagonistic effect of selective neuronal nitric-oxide synthase (nNOS) inhibitor 7-nitroindazole on the long-term potentiation (LTP) induced by l-clausenamide (Cla) in rat hippocampus in vivo.


METHODS
Population spike (PS) of evoked potentials was determined by extracellular recording technique in the hippocampal dentate gyrus (DG) of anesthetized rats.


RESULTS
7-Nitroindazole 2 nmol icv blocked the induction of LTP elicited by high-frequency (100 Hz) stimulation or Cla 5 nmol icv (P < 0.01), and L-arginine 225 mg.kg-1 i.p. prevented the action of 7-nitroindazole (P < 0.01).


CONCLUSIONS
Nitric oxide produced by nNOS plays a role in the induction of Cla-induced LTP in hippocampus.
Zhao
M R
MR
Department of Pharmacology, Chinese Academy of Medical Sciences, Beijing, China.
Zhang
J T
JT
D000818:Animals; D018891:Dentate Gyrus / Q000502:physiology*; D004365:Drugs, Chinese Herbal / Q000737:chemistry; D005071:Evoked Potentials / Q000187:drug effects; D007191:Indazoles / Q000494:pharmacology*; D007769:Lactams / Q000037:antagonists & inhibitors* / Q000302:isolation & purification; D017705:Lignans; D017774:Long-Term Potentiation / Q000187:drug effects*; D008297:Male; D018696:Neuroprotective Agents / Q000494:pharmacology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D052248:Nitric Oxide Synthase Type I; D051381:Rats; D017207:Rats, Sprague-Dawley; D009435:Synaptic Transmission
D004365:Drugs, Chinese Herbal; D007191:Indazoles; D007769:Lactams; D017705:Lignans; D018696:Neuroprotective Agents; C053048:clausenamide; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; C496322:Nos1 protein, rat; C080122:7-nitroindazole