Effects of a depressant/convulsant pair of glutarimides on neuronal activity in the isolated spinal cord of the immature rat.
The effect of depressant/convulsant pair of glutarimides on the isolated spinal cord of the immature rat was examined using extracellular recording. At concentrations of 300 microM the depressant beta-butyl-beta-methyl glutarimide enhanced the response of motoneurones and dorsal root fibres to gamma-aminobutyric acid (GABA) while the convulsant bemegride (beta-ethyl-beta-methyl glutarimide) decreased both responses to GABA. At this concentration both the convulsant and depressant reduced mono- and polysynaptic reflex activity. Neither the convulsant or depressant had prominent direct actions, with only a small hyperpolarization being produced by both glutarimides on dorsal root fibres. The overall depressant or convulsant properties of these glutarimides may be due in part therefore to a differential effect on the postsynaptic action of the inhibitory transmitter GABA. Furthermore, the depressant glutarimide reduced the excitatory effects of L-glutamate and the convulsant reduced the inhibitory effects of glycine on spinal neurones; thus, actions on these transmitters may also contribute to the overall effects of these glutarimides.
D000596:Amino Acids / Q000494:pharmacology; D000818:Animals; D001534:Bemegride / Q000494:pharmacology; D002492:Central Nervous System Depressants / Q000494:pharmacology*; D003292:Convulsants / Q000494:pharmacology*; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D009474:Neurons / Q000187:drug effects*; D010880:Piperidines / Q000494:pharmacology*; D010881:Piperidones / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012023:Reflex, Monosynaptic / Q000187:drug effects; D013116:Spinal Cord / Q000187:drug effects*; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D000596:Amino Acids; D002492:Central Nervous System Depressants; D003292:Convulsants; D010880:Piperidines; D010881:Piperidones; D005680:gamma-Aminobutyric Acid; D001534:Bemegride; C007864:glutarimide