EFFECTS OF DEOXYCORTICOSTERONE ACETATE AND DIAZEPAM ON NEUROPEPTIDERGIC NEURONS IN RAT STRIATUM

THE neurosteroid tetrahydrodeoxycorticosterone (THDOC) interacts with gamma-aminobutyric acid (GABA)/ benzodiazepine (BZ) receptors. To test the hypothesis that THDOC works partially through mechanisms associat ed with GABA(A)/BZ receptor function, deoxycorticosterone acetate (DOC A) and the benzodiazepine, diazepam (DZ), were administered short- (1 day) and long-term (11 days). Levels of mRNA for dynorphin, preprotach ykinin and preproenkephalin in the striatum of adult male Sprague-Dawl ey rats were measured by in situ hybridization. Acute DOCA and DZ trea tment produced parallel neuropeptide mRNA profiles, whereas chronic DO CA and DZ treatment yielded different patterns of neuropeptide gene ex pression. Chronic DZ treatment resulted in no significant increase in salt intake whereas chronic DOCA activated salt appetite. We suggest t hat acute DZ and DOCA interact with GABA(A)/BZ receptors; however, the results of chronic treatment suggest that DZ and DOCA operate through dissimilar mechanisms.