Effect of anticonvulsants on pentylenetetrazol-induced power spectrum changes in electroencephalograms in rats.
The effect of anticonvulsants on pentylenetetrazol (PTZ)-induced EEG power spectrum changes was examined. When the minimum dose of PTZ (15 mg/kg) was administered intravenously twice, with an interval of 80 min, a clear EEG power spectrum change was observed after the second PTZ administration, irrespective of whether or not the first PTZ administration evoked marked EEG changes. We defined the values F/N, S/N and S/F. The value F/N, obtained by dividing the power spectrum area after the first PTZ administration by the normal power spectrum area, was 1.06 +/- 0.05 (mean +/- S.E.). The value S/N, obtained by dividing the power spectrum area after the second PTZ administration by the normal power spectrum area, was 2.00 +/- 0.21. The value S/F, obtained by dividing S/N by F/N, was 1.86 +/- 0.16. The S/F value was almost constant regardless of whether or not the first PTZ administration could evoke marked EEG changes. The effect of anticonvulsants was examined by S/F value changes, and 100 mg/kg of PHT completely inhibited the double PTZ effect. Phenobarbital, ethosuximide and sodium valproate also inhibited the double PTZ effect. Using the S/F value of the EEG power spectrum with minimum dose double PTZ administration, quantitative evaluation is possible for anticonvulsant drugs.
Sugaya
E
E
Department of Physiology, Kanagawa Dental College, Yokosuka, Japan.
Ishige
A
A
Sekiguchi
K
K
Iizuka
S
S
Sakamoto
K
K
Matsuzaki
Y
Y
Aburada
M
M
Hosoya
E
E
D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology / Q000627:therapeutic use*; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology*; D000242:Cyclic AMP / Q000378:metabolism; D004569:Electroencephalography; D005013:Ethosuximide / Q000494:pharmacology / Q000627:therapeutic use; D008297:Male; D010433:Pentylenetetrazole; D010634:Phenobarbital / Q000494:pharmacology / Q000627:therapeutic use; D051381:Rats; D011919:Rats, Inbred Strains; D012640:Seizures / Q000139:chemically induced / Q000188:drug therapy* / Q000503:physiopathology; D014635:Valproic Acid / Q000494:pharmacology / Q000627:therapeutic use
D000927:Anticonvulsants; D005013:Ethosuximide; D014635:Valproic Acid; D000242:Cyclic AMP; D010433:Pentylenetetrazole; D010634:Phenobarbital