Inhibition of nitric oxide synthase influences the activity of striatal neurons in the rat.
The activity of single units in the striatum of urethane-anesthetized rats was recorded before and after the systemic administration of 7-nitro-indazole (7-NI; 50 mg/kg intraperitoneally), a selective inhibitor of neuronal nitric oxide (NO) synthase. Two neuronal types were clearly distinguishable electrophysiologically, on the basis of either discharge frequency pattern or features of the individual spike waveform (spike duration, negative phase/total duration ratio, and negative phase/total amplitude ratio). Only sporadically discharging neurons (basal firing rate, <0.1 spikes/s) were influenced by 7-NI, which caused a statistically significant increase in their firing rate. In contrast, the activity of continuously discharging neurons (basal firing rate, 4-6 spikes/s) was not affected. We hypothesize that NO neurotransmission could exert a tonic inhibitory influence upon sporadically discharging striatal neurons, which are presumably striatal output neurons.
Sardo
Pierangelo
P
Dipartimento di Medicina Sperimentale, Sezione di Fisiologia Umana, Università degli Studi di Palermo, Corso Tukory, 129-90134 Palermo, Italy.
Ferraro
Giuseppe
G
Di Giovanni
Giuseppe
G
Galati
Salvatore
S
La Grutta
Vittorio
V
D000200:Action Potentials; D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects* / Q000201:enzymology / Q000502:physiology; D004594:Electrophysiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007191:Indazoles / Q000494:pharmacology; D008297:Male; D009419:Nerve Tissue Proteins / Q000037:antagonists & inhibitors; D009569:Nitric Oxide / Q000378:metabolism / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D052248:Nitric Oxide Synthase Type I; D051381:Rats; D017208:Rats, Wistar
D004791:Enzyme Inhibitors; D007191:Indazoles; D009419:Nerve Tissue Proteins; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; C496322:Nos1 protein, rat; C080122:7-nitroindazole