ACUTE EFFECTS OF ETHANOL ON RECURRENT INHIBITORY CIRCUITS OF CA1 NEURONS IN-VIVO

This study examined the dose-dependent effects of acute ethanol on rec urrent inhibitory mechanisms of hippocampal CA1 neurons in anesthetize d rats. The effects of micropressure-ejected GABAergic compounds were studied on evoked field responses and recurrent inhibition of CA1 pyra midal neurons. None of the systemic doses of ethanol examined altered recurrent inhibition of CA1 neurons. In contrast, local application of both GABAa and GABAb compounds produced clear changes in evoked field responses and blocked recurrent inhibition. These results suggest tha t (a) recurrent inhibition in the CA1 region in vivo is resistant to t he effects of ethanol, and (b) both GABAergic receptor subtypes modula te recurrent inhibition in the CA1 region in vivo.