Effect of ethanol administration on axoplasmic flow in the brain

Abstract

The effect of ethanol administration on the axoplasmic flow of protein in the rat brain was studied by a subcellular fractionation procedure after intraventricular administration of [ 14C]-leucine. The fast component of axoplasmic transport was facilitated following continuous ingestion of ethanol for 1–3 weeks. Fractionation of the lysed nerve ending into components showed that an increase in the fast axoplasmic transport of protein was associated with synaptic vesicles and mitochondria. Neither slow axoplasmic transport nor the soluble component of fast axoplasmic flow were altered following continuous ethanol administration. The acute administration of ethanol (3 g/kg body weight, intraperitoneally) also increased the fast axoplasmic transport of protein in paniculate fractions without altering slow axoplasmic flow or the soluble component of fast axoplasmic flow. These changes in fast axoplasmic transport were reversed following the withdrawal of ethanol administration and were not affected by the administration of cycloheximide, a protein synthesis inhibitor. These results indicate clearly that ethanol, administered either acutely or chronically, induces an increase in the fast axoplasmic flow of particulates from the nerve cell body to the nerve ending. Because of well-known and important roles of the fast axoplasmic flow in synaptic function, these changes in axoplasmic flow may well be important in the alteration of CNS function due to ethanol.