Ethanol modulates the expression of GABAB receptor mRNAs in the prenatal rat brain in an age and area dependent manner

Prenatal ethanol exposure has various deleterious effects on neuronal development. As GABAB receptor is known to play an important role during the development of the CNS, we now focused on its mRNA expression pattern in the rat brain during the late gestational days (GD) from 15.5 to GD 21.5. Ethanol's effect was also observed from GD 11.5 to GD 21.5. GABAB1 receptor mRNA showed a high expression level in GD 15.5 and 19.5, while GABAB2 receptor mRNA did in GD 15.5 and 21.5. The mRNAs levels depended on age and area during development. Ethanol exposure decreased GABAB1 receptor from GD 11.5 to GD 19.5 with slight increases in GD 21.5. The decreasing effects were area dependent, with the highest effects in the forebrain including cortex, whereas slight effects were observed in the midbrain and hindbrain. The present results suggest an important role of GABAB receptor in the effects of ethanol on prenatal brain developmental processes.