Taurine protects cerebellar neurons of the external granular layer against ethanol-induced apoptosis in 7-day-old mice

Abstract

Acute alcohol administration is harmful especially for the developing nervous system, where it induces massive apoptotic neurodegeneration leading to alcohol-related disorders of newborn infants. Neuroprotection against ethanol-induced apoptosis may save neurons and reduce the consequences of maternal alcohol consumption. Previously we have shown that taurine protects immature cerebellar neurons in the internal granular layer of cerebellum from ethanol-induced apoptosis. Now we describe a similar protective action for taurine in the external layer of cerebellum of 7-day-old mice. The mice were divided into three groups: ethanol-treated, ethanol + taurine-treated and controls. Ethanol (20% solution) was administered subcutaneously at a total dose of 5 g/kg (2.5 g/kg at time 0 h and 2.5 g/kg at 2 h) to the ethanol and ethanol + taurine groups. The ethanol + taurine group also received subcutaneously two injections of taurine (1 g/kg each, 1 h before the first dose of ethanol and 1 h after the second dose of ethanol). To verify apoptosis, immunostaining for activated caspase-3 and TUNEL staining were made in the mid-sagittal sections containing lobules I-X of the cerebellar vermis at 8 h after the first ethanol injection. Ethanol induced apoptosis in the cerebellar external granular layer. Taurine treatment significantly reduced the number of activated caspase-3-immunoreactive and TUNEL-positive cells. Taurine has thus a neuroprotective antiapoptotic action in the external granular layer of the cerebellum, preserving a number of neurons from ethanol-induced apoptosis.