Alcohol-mediated Purkinje cell loss in the absence of hypoxemia during the third trimester in an ovine model system.
BACKGROUND
Although the mechanisms that underlie fetal alcohol-induced neuronal loss have not been determined, hypoxia/hypoxemia has been considered a leading candidate. This study was designed to test the hypothesis that neuronal loss could occur in the developing brain in the absence of fetal hypoxemia.


METHODS
Three groups of pregnant sheep were used: a control group, a binge-drinking group, and a pair-fed group. The alcohol and pair-fed animals were anesthetized on day 113 of pregnancy, and the mothers and fetuses were instrumented with arterial and venous catheters. All animals were killed on day 133. Stereological cell counting techniques were used to estimate the total number of Purkinje cells in the fetal cerebellum.


RESULTS
Peak maternal and fetal blood alcohol concentrations did not produce fetal hypoxemia. Nevertheless, there was a 25% loss of Purkinje cells of the cerebellum in the alcohol-exposed fetuses compared with that in the pair-fed controls. The loss of neurons was not accompanied by microencephaly or a concomitant decrease in either cerebellar weight or volume of the fetal cerebellum.


CONCLUSIONS
Neuronal loss can be observed after alcohol exposure during the third trimester equivalent in fetal sheep in the absence of alcohol-induced hypoxemia. Furthermore, cell loss in the absence of deficits in gross brain weight or regional brain volume indicates that the lack of gross brain volume deficits from magnetic resonance imaging techniques is not a reliable indication that the brain is unaffected by the alcohol exposure.
West
J R
JR
Department of Human Anatomy and Medical Neurobiology, College of Medicine, The Texas A&M University System Health Science Center, College Station, Texas 77843-1114, USA. jrwest@tamu.edu
Parnell
S E
SE
Chen
W J
WJ
Cudd
T A
TA
D000465:Algorithms; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D001921:Brain / Q000187:drug effects / Q000473:pathology; D002452:Cell Count; D002492:Central Nervous System Depressants / Q000494:pharmacology*; D002531:Cerebellum / Q000473:pathology*; D000431:Ethanol / Q000494:pharmacology*; D005260:Female; D000860:Hypoxia / Q000473:pathology*; D009929:Organ Size / Q000187:drug effects; D011247:Pregnancy; D011689:Purkinje Cells / Q000473:pathology*; D012756:Sheep
D002492:Central Nervous System Depressants; D000431:Ethanol