Prenatal ethanol exposure decreases hippocampal 3H-vinylidene kainic acid binding in 45-day-old rats.
The effect of prenatal ethanol exposure on the kainate-sensitive subtype of glutamate receptor binding sites was studied using in vitro 3H-vinylidene kainic acid (VKA) autoradiography. Pregnant Sprague-Dawley rats were fed a liquid diet containing either 3.35% or 6.7% ethanol throughout gestation. Pair-fed dams received isocalorically matched liquid diets and a lab chow ad lib group served as control for paired feeding. At 45 days of age, the offspring were sacrificed and their brains analyzed for specific 3H-VKA binding. Compared to pair-fed controls, specific 3H-VKA binding was reduced by 13% to 32% in dorsal and ventral hippocampal CA3 stratum lucidum, entorhinal cortex and cerebellum of 45-day-old rats whose mothers consumed either 3.35% or 6.7% ethanol diets. The binding site reductions were statistically significant only in the ventral hippocampal formation and entorhinal cortex of the 3.35% ethanol diet group rats. Saturation of binding studies in the ventral hippocampal formation of 3.35% ethanol rats indicated that the decrease in specific 3H-VKA binding was due to a decrease in the total number of binding sites. Given the excitatory effect of kainic acid on the spontaneous firing rate of hippocampal CA3 pyramidal neurons, the reduction of kainate-sensitive glutamate binding in this region is consistent with the electrophysiological observation of decreased spontaneous activity of CA3 pyramidal neurons in fetal alcohol rats.
Farr
K L
KL
Department of Pharmacology, University of New Mexico School of Medicine, Albuquerque 87131.
Montano
C Y
CY
Paxton
L L
LL
Savage
D D
DD
D000437:Alcoholism / Q000378:metabolism; D000818:Animals; D001345:Autoradiography; D005260:Female; D063647:Fetal Alcohol Spectrum Disorders / Q000378:metabolism*; D006624:Hippocampus / Q000378:metabolism*; D007608:Kainic Acid / Q000378:metabolism*; D007700:Kinetics; D011247:Pregnancy; D011248:Pregnancy Complications / Q000378:metabolism; D051381:Rats; D018092:Kainic Acid Receptors; D017981:Receptors, Neurotransmitter / Q000378:metabolism*; D012016:Reference Values; D014316:Tritium; D014753:Vinyl Compounds / Q000378:metabolism*
D007608:Kainic Acid; D018092:Kainic Acid Receptors; D017981:Receptors, Neurotransmitter; D014316:Tritium; D014753:Vinyl Compounds