Developmental Changes in the Brain Levels of Neurotransmitters as Influenced by Maternal Ethanol Consumption in the Rat1

Effects of prolonged maternal ethanol consumption by pregnant and lactating rats were investigated on the cerebral contents of certain neurotransmitters and the activities of their enzymes in fetal and neonatal brains. Ethanol consumption by the pregnant rats resulted in a significant decrease in the fetal brain contents of acetylcholine and an increase in γ‐aminobutyric acid and glutamate. The cerebral levels of 5‐hydroxytryptamine (5‐HT), norepinephrine of choline in the fetal brains from the ethanol group were not significantly different from those observed in the control group. With the increase in gestational age, an increase in the levels of 5‐HT, norepinephrine, acetylcholine, γ‐amino‐butyric acid (GABA) and glutamate was observed in the fetal brains from both ethanol and control groups. The brains of neonates suckling on ethanol‐fed mothers showed a significant decrease in acetylcholine levels and an increase in GABA and glutamate levels as compared to the corresponding controls. The activities of L‐glutamate decarboxylase and GABA‐aminotransferase in the fetal as well as neonatal brains were decreased in the ethanol‐fed group as compared to the controls. A single injection of acetaldehyde resulted in a decrease in acetylcholine, GABA and glutamate levels in both neonatal and adult brains.