Regional rat brain benzodiazepine receptor number and gamma-aminobutyric acid concentration following a convulsion.
1 Following administration to rats of an electroconvulsive shock (ECS) which resulted in a major tonic-clonic seizure, no changes in [3H]-diazepam binding characteristics were observed in cortex or hippocampus with either a well washed membrane preparation or a crude synaptosomal preparation. 2 No changes were observed in [3H]-diazepam binding in any other brain region examined 30 min after an ECS. 3 Thirty min following an ECS, regional brain gamma-aminobutyric acid (GABA) concentrations increased in hippocampus, cortex and hypothalamus. Only in the hippocampus did the increase occur within 5 min of the seizure. 4 Similar increases in GABA concentration were seen after a bicuculline-induced seizure but not after seizure induced by flurothyl; both treatments produced a tonic-clonic seizure. 5 Pretreatment of the rats with (+)-propranolol 5 min before the ECS abolished the tonic extension and prevented the brain GABA concentration changes that occur 30 min after the seizure. 6 No increase in GABA concentration was seen in hippocampus, cortex and hypothalamus 30 min after the final ECS of a course of 10 ECS given once daily for 10 days. In contrast a marked increase in striatal GABA concentration was observed. 7 These changes in GABA biochemistry following a seizure are discussed in relation to the post-ictal rise in seizure threshold that is occurring at the same time.
D000758:Anesthesia; D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D001921:Brain / Q000378:metabolism*; D004597:Electroshock; D008297:Male; D009419:Nerve Tissue Proteins / Q000378:metabolism; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011955:Receptors, Drug / Q000378:metabolism*; D011963:Receptors, GABA-A; D012640:Seizures / Q000139:chemically induced / Q000378:metabolism*; D013574:Synaptosomes / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D009419:Nerve Tissue Proteins; D011955:Receptors, Drug; D011963:Receptors, GABA-A; D005680:gamma-Aminobutyric Acid; D011433:Propranolol; D001640:Bicuculline