1. Acute ethanol administration resulted in an increase in the total number of specific somatostatin receptors in rat frontoparietal cortex and hippocampus, and a decrease in the level of somatostatin-like immuno-reactivity in the hippocampus but not in the frontoparietal cortex.
2. Chronic administration of ethanol caused a decrease in the number of somatostatin receptors in the frontoparietal cortex but not in the hippocampus, although the level of somatostatin-like immunoreactivity was unchanged in both brain areas.
3. A week after suppressing ethanol the value for specific binding of tracer to somatostatin receptors in the frontoparietal cortex was not significantly different from that of the control rats, although the actual number of receptors was slightly lower.
4. These results suggest a possible role for somatostatin in the nervous system during alcoholism and the post-withdrawal reaction.