Learned tolerance to the anticonvulsant effects of alcohol in rats.

Ethanol (1.5 g/kg, IP) administered to kindled rats blocked the seizures normally elicited in these subjects by electrical stimulation of the amygdala. Tolerance to this anticonvulsant effect developed following a series of ethanol injections only when the amygdaloid stimulation was administered during the periods of ethanol intoxication. Control subjects stimulated each day prior to ethanol administration displayed no tolerance to ethanol's anticonvulsant effects. Such findings emphasize the important role of learning in the development of alcohol tolerance and support the view that tolerance develops more rapidly for responses that are affected by the alcohol exposure.