Effect of neonatal ethanol exposure on parvalbumin-expressing GABAergic neurons of the rat medial septum and cingulate cortex

This study was performed to determine the long-term effects of ethanol expo sure during the brain growth spurt (postnatal days 4-10) on the number of p arvalbumin-immunoreactive (PA+) GABAergic neurons in the adult (P60) rat me dial septum and anterior cingulate cortex. Significant loss of neurons with in each of these populations has previously been demonstrated following pre natal ethanol exposure. In the present study, no significant differences in the number of PA+ neurons were found in either the medial septum or the ci ngulate cortex when control and ethanol-exposed animals were compared. The cellular densities and Volumetric measures in both brain regions were also similar in the two groups. We speculate that compensatory up-regulative mec hanisms may have accounted for the protection of the PA neuronal population s in these two areas following the early neonatal exposure. (C) 2000 Elsevi er Science Inc. All rights reserved.