Regional GABA-stimulated chloride uptake in amygdala kindled rats.
gamma-Aminobutyric acid (GABA)-stimulated 36chloride (Cl-) influx into membrane vesicles derived from cerebral cortex, hippocampus, cerebellum and midbrain/brainstem was evaluated in naive rats and amygdala or sham kindled rats. GABA-stimulated 36Cl- uptake was greatest in cortex and hippocampus of naive rats. One week after amygdala kindling, 10 microM GABA-stimulated 36Cl- influx was significantly reduced in each brain region, except midbrain/brainstem, indicating a regional variation in impaired GABAergic function. Midazolam potentiation of GABA-mediated Cl- flux showed a regional variation. The effect of midazolam in kindled rats indicated either an increase in efficiency of GABA/benzodiazepine coupling in areas of reduced GABA function or its ability to restore Cl- channel function to the pre-kindled state.
Tietz
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Department of Pharmacology, Medical College of Ohio, Toledo 43699.
Chiu
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D000679:Amygdala / Q000502:physiology*; D000818:Animals; D001921:Brain / Q000378:metabolism*; D002712:Chlorides / Q000493:pharmacokinetics*; D002713:Chlorine; D004357:Drug Synergism; D007696:Kindling, Neurologic; D008297:Male; D008874:Midazolam / Q000494:pharmacology; D011868:Radioisotopes; D051381:Rats; D011919:Rats, Inbred Strains; D014018:Tissue Distribution; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D002712:Chlorides; D011868:Radioisotopes; D002713:Chlorine; D005680:gamma-Aminobutyric Acid; D008874:Midazolam