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.