EFFECT OF DEPLETION OF BRAIN CATECHOLAMINES ON ETHANOL TOLERANCE AND DEPENDENCE

Brain catecholamines were depleted in rats by intraventricular injection with 6-hydroxydopamine, prior to feeding rats on a liquid diet containing ethanol. On withdrawal of ethanol, withdrawal reactions were significantly more severe in catecholamine-depleted rats than control rats. Sleeping times after a standard dose of ethanol or pentobarbitone were significantly reduced in catecholamine-depleted animals. However, after prolonged ethanol treatment, tolerance developed to a similar extent in catecholamine-depleted rats as in controls. The effects on sleeping time and withdrawal severity were most probably due to the depletion of noradrenaline as they were not observed after a specific depletion of dopamine. It was concluded that these effects were due to a non-specific increase in CNS excitability resulting from depletion of noradrenaline and that central catecholamines do not play a direct role in the development of ethanol tolerance and physical dependence. © 1979.