The effects of anticonvulsant drugs on NMDA-EPSP, AMPA-EPSP, and GABA-IPSP in the rat hippocampus.
The effects of phenobarbital, phenytoin, and valproic acid on pharmacologically isolated NMDA-EPSP, AMPA-EPSP, and GABA-IPSPs were examined in rat hippocampal slices. Phenobarbital (0.05 mg/ml) had no effect on the NMDA-EPSP, but decreased the slope of the AMPA-EPSP by 13.4% and facilitated the GABA-IPSP slope by 77.12%. Phenytoin (0.02 mg/ml) had no effects on the NMDA-EPSP, AMPA-EPSP, or GABA-IPSP. Valproic acid (0.1 mg/ml) decreased the NMDA-EPSP slope by 14.3%, increased the GABA-IPSP slope by 54.34%, and had no effect on the AMPA-EPSP. These data suggest that the mechanisms of action of these anticonvulsant drugs may be via their actions on different neurotransmitter systems or ion channels.
Ko
G Y
GY
Department of Neurobiology, Northeastern Ohio Universities College of Medicine, Rootstown 44272-0095, USA.
Brown-Croyts
L M
LM
Teyler
T J
TJ
D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology*; D004594:Electrophysiology; D006624:Hippocampus / Q000187:drug effects* / Q000502:physiology; D008297:Male; D016202:N-Methylaspartate / Q000494:pharmacology*; D010634:Phenobarbital / Q000494:pharmacology; D010672:Phenytoin / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D014635:Valproic Acid / Q000494:pharmacology; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000494:pharmacology*; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D000927:Anticonvulsants; D005680:gamma-Aminobutyric Acid; D014635:Valproic Acid; D010672:Phenytoin; D016202:N-Methylaspartate; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D010634:Phenobarbital