Effects of ethanol on 5-hydroxytryptamine release from rat corpus striatum in vivo

The effects of ethanol administration on the release of 5-hydroxytryptamine (5-HT) within the corpus striatum of the rat was investigated using in vivo dialysis cannulae. Fifteen-minute dialysate samples were continuously collected from up to 5.25 hr from individual, urethane-anesthetized rats and analyzed for their content of 5-hydroxyindoleacetic acid (5-HIAA) by HPLC-electrochemical detection. Ethanol injected intraperitoneally caused an increase of 5-HT release reflected as an increase in the concentrations of 5-HIAA in perfusion samples. Comparison of two doses of ethanol resulting in maximum blood ethanol concentrations of 50 mM versus 80 mM, showed that the lower dose elicited a more rapid, longer lasting and significantly greater increase in release. The results emphasise the importance of monitoring the time courses of neurochemical events associated with alcohol treatment in individual animals, and demonstrate the value of the in vivo dialysis cannula technique in that context.