Inhibition by N omega-nitro-L-arginine methyl ester of the electrocortical arousal response in rats.
In rats chronically implanted with cannulae into one lateral cerebral ventricle and recording electrodes onto the fronto-parietal cortex, the effects of systemic or intraventricular administration of the nitric oxide (NO) synthesis inhibitor, N omega-nitro-L-arginine methyl ester (L-NAME), on electrocortical (ECoG) arousal response evoked by sound stimulation were studied. In control animals, a single acoustic stimulation (80 dB for 15 s) produced a significant decrease in ECoG total voltage power lasting approximately 25 s. No tolerance developed after repeating the same sound stimulation at 15, 30, 60 min and 24 h intervals. Under these experimental conditions, pretreatment with L-NAME, given systemically (10 mg kg-1, i.p.) or intracerebroventricularly (300 micrograms), significantly reduced the sound-evoked arousal response 1 h and 15 min later, respectively. In conclusion, the present data are in favour of a physiological role of NO in the control of arousal mechanisms.
Bagetta
G
G
Department of Biology, University of Rome Tor Vergata, Italy.
Iannone
M
M
Del Duca
C
C
Nisticò
G
G
D000161:Acoustic Stimulation; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000494:pharmacology; D001143:Arousal / Q000502:physiology*; D002540:Cerebral Cortex / Q000187:drug effects / Q000502:physiology*; D003344:Cortical Synchronization / Q000187:drug effects; D004569:Electroencephalography / Q000187:drug effects; D004594:Electrophysiology; D007276:Injections, Intraventricular; D008297:Male; D019331:NG-Nitroarginine Methyl Ester; D051381:Rats; D017208:Rats, Wistar
D001120:Arginine; D019331:NG-Nitroarginine Methyl Ester