Effects of 6-hydroxydopamine or 5,7-dihydroxy-tryptamine on the development of physical dependence on ethanol.

Infant rats, treated intracisternally with 6-hydroxydopamine or 5,7-dihydroxytryptamine, alone or in combination with desmethylimipramine or pargyline, at 5 to 7 days of age, had significant specific depletions of brain norepinephrine, dopamine, both of these amines, or serotonin at 2.5 months of age. Despite apparent long-term depletions of brain biogenic amines, susceptibility to audiogenically-induced seizures following chronic ethanol withdrawal in these animals was similar to that of controls. Amine-depleted rats also displayed spontaneous withdrawal-induced tremors, spastic motor activity and irritability. The interpretation of these preliminary findings with regard to the proposed role of the biogenic amines in the development of physical dependence on ethanol is discussed.