Prenatal cocaine exposure alters glycogen synthase kinase-3β (GSK3β) pathway in select rabbit brain areas

Abstract Prenatal cocaine exposure in rabbits induces cerebrocortical structural abnormalities. Glycogen synthase kinase-3β (GSK3β) plays an important role in neuronal development and survival. This study was designed to examine the effect of prenatal cocaine on brain GSK3β. Rabbits exposed in utero to cocaine and assessed on postnatal day 20 had increased basal levels of phospho-GSK3β (ser-9) in frontal cortex (FCX) and striatum, but not hippocampus (HP). However, no changes in GSK3β expression were detected in the brain regions of treated rabbits. Consistent with the change in GSK3β activity, levels of β-catenin, a downstream substrate of GSK3β, increased in FCX but not in HP of cocaine offspring. Administration of a D 1 dopamine receptor agonist inhibited GSK3β activity in FCX and HP of control rabbits but not in cocaine offspring. This loss of GSK3β inhibition is in accord with the previously demonstrated dysfunction of this receptor in in utero cocaine-exposed animals. The results indicate that prenatal cocaine exposure alters GSK3β pathway in select brain areas and may underlie the structural changes noted in these animals.