Dopaminergic and serotonergic alterations in the rat brain during ethanol withdrawal: association with behavioral signs

Changes in dopaminergic and serotonergic levels and metabolites in cerebral cortex, corpus striatum and hippocampus were investigated during the first 6-h of withdrawal in ethanol-dependent Wistar rats. Ethanol was given by a liquid diet for 21 days. The concentration of ethanol was 7.2% (v/v) for t he last 15 days of the exposure. After 2, 4 and 6 h of ethanol withdrawal, and after audiogenic stimulus (100 dB for 60 s) at 6 h of ethanol withdrawa l, various brain regions were assayed for levels of dopamine (DA), DOPAC, H VA, serotonin (5-HT) and 5-HIAA. Behavioral signs of ethanol withdrawal and blood ethanol levels were also evaluated in other parallel groups of ethan ol-dependent rats. Significant decreases in 5-HT levels and significant inc reases in HVA levels in striatum were found during the first 6 h of ethanol withdrawal and after the audiogenic seizures. In hippocampus, 5-HIAA level s were significantly reduced after 2 h of ethanol withdrawal and after the audiogenic seizures. 5-HIAA levels significantly increased after 2 h of eth anol withdrawal in cerebral cortex. Significant increases in both DA and 5- HT levels were also found in cerebral cortex after the audiogenic seizures. The results suggest that the levels of DA, 5-HT and their metabolites are altered by ethanol withdrawal. Furthermore, this may suggest that DA and 5- HT may be involved in the first 6 h of ethanol withdrawal syndrome in rats. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.