TEMPORAL DETERMINANTS OF NEONATAL ALCOHOL-INDUCED CEREBELLAR DAMAGE AND MOTOR-PERFORMANCE DEFICITS

The timing and duration of alcohol exposure was manipulated in neonata l rats by using a ''binge'' model of alcohol exposure during the ''thi rd trimester equivalent.'' Groups of Sprague-Dawley rats were exposed to binges via artificial rearing on postnatal days (PD) 4-9, on PD 4-6 or on PD 7-9, which produced peak blood alcohol concentrations repres entative of human alcohol abusers (similar to 250 mg/dl). Motor perfor mance was assessed using parallel bar traversal on PD 42-44 and total Purkinje cell numbers were determined by using the 3-dimensional stere ological optical fractionator method. PD 4-9 binge exposure induced th e most severe Purkinje cell loss (to 68% of controls) and PD 4-6 binge exposure also produced significant loss (to 86% of controls), whereas PD 7-9 binge exposure had no significant effect (98% of controls). Un expectedly, all three alcohol treatments resulted in significant impai rments on the parallel bar task. The time of exposure during the early neonatal period in rats strongly influences the degree of Purkinje ce ll loss, but Purkinje cell loss is not necessary for the alcohol-induc ed motor performance deficits, Both neuromorphological and neurobehavi oral assessments are needed fur a full description of alcohol-related neurodevelopmental disorders. Copyright (C) 1996 Elsevier Science Inc.