Effects of ethanol, given during pregnancy, on the offspring dopaminergic system

The fetal alcohol syndrome is characterized by a number of abnormalities consisting of a pre- and post-natal growth deficiency, microcephaly, areas of abnormal nerve cell migration in the brain, mental and psychomotor retardation in children of alcoholic women. These findings may be referred as a teratogenic effect of ethanol on the central nervous system. In order to investigate the above ethanol-neurotoxic effect the striatal dopaminergic transmission was studied. The dopaminergic turnover was measured by 3,4-dihyroxyphenilacetic acid content and 3H-Spiperone binding has been carried out to determine dopaminergic receptor alterations induced by chronic ethanol consumption during pregnancy. Our work demonstrates long-lasting modifications of dopaminergic neuronal function after exposure of the experimental animal to ethanol during fetal life. In particular, a decreased receptor function has been observed in rats exposed to ethanol only during the perinatal period. In the same group of rats, diminished receptor activity leads to an enhancement in DOPAC content still detectable after a long period from cessation of ethanol treatment. Neurochemical data are reinforced by behavioral observations. In fact, a significant decrease of spontaneous locomotor activity in the rats chronically treated with ethanol during fetal life was observed. In addition, the altered response of locomotor activity after drug administration may be ascribed to the modified dopaminergic function. With this experimental approach we assume that the action of ethanol on the central nervous system may be a marker of its teratogenic effect.