In earlier studies, we investigated the influence of undernutrition on the electrophysiological and neuromorphological parameters of the developing rat cerebellar Purkinje neurons. Undernutrition was induced by increasing the liter size to 16 pups and simultaneously restricting the mother’s dietary intake of protein, casein to 50% of her daily requirement; while normal animals were reared in the litters of 8 and their mothers were fed an ad libitum diet as described by Widdowson and McCance (1957). Lactating mothers in both experimental groups received a high protein diet containing 25% casein. This experimental model was utilized because the rat cerebellar Purkinje neurons develop postnatally and are highly vulnerable to the deleterious effects of undernutrition. The cerebellar tissue was processed for light and E.M. study as described in our earlier publications (Sharma et al. 1986; Sharma et al. 1987).