Alcohol-induced Purkinje cell loss with a single binge exposure in neonatal rats: A stereological study of temporal windows of vulnerability

Previous research has shown that the early neonatal period of rats is one of enhanced vulnerability to cerebellar Purkinje cell loss associated with binge-like alcohol exposure, with a prominent sensitive period during the first neonatal week. In this study, an unbiased count of the total number of Purkinje cells was obtained using the stereological optical fractionator, in groups of rats given a single hinge-like alcohol exposure either during the most vulnerable neonatal period [postnatal day (PD) 4] or during a later, less vulnerable period (PD 9). Using artificial rearing methods, rats were given 6.6 g/kg of alcohol either on PD 4 or can PD 9, delivered as a 15% (v/v) solution in milk formula on two consecutive feedings of the designated day. Central groups included an artificially reared gastrostomy control and a normally reared suckle control. The mean peak blood alcohol concentrations were no: different between the PD 4 and PB 9 alcohol groups, averaging 374 and 347 mg/dl, respectively. The rats were perfused on PD 27. A uniform random sample of sections was obtained from serial frozen sections through the cerebellum, stained with thionin, and Purkinje cells were counted from a uniform random sample of locations on each section with the three-dimensional optical fractionator. The number of Purkinje cells in the suckle control and gastrostomy control groups did not differ from each other, averaging 3.94 (+/-0.19) and 3.58 (+/-0.22) x 10(5) cells, respectively. Binge exposure on PD 4 induced significant cell loss (mean of 2.05 +/- 0.20 x 10(5) Purkinje cells), whereas binge exposure an PD 9 did not induce significant Purkinje cell lass (3.70 +/- 0.39 x 10(5) Purkinje cells). These findings confirm that a single neonatal binge alcohol exposure produces pathological Purkinje cell loss, provided that it occurs during the period of enhanced vulnerability coinciding with the early stages of dendritic outgrowth.