[The effect of methylazoxymethanol on neuronal differentiation in the murine cerebellum].

The effect of methylazoxymethanol (MAM), an antimitotic drug, on granule and Purkinje cells of the rat cerebellum was studied. MAM was injected subcutaneously into ICR mice on day 5 after birth. The number of nucleoli and DNA content in nuclei of cerebellar neurons were determined 2 and 12 days after the injection. The number of nucleoli served as a criterion of maturity of neurons. On day 2 after MAM administration the proportion of Purkinje cells containing a smaller number of nucleoli increased suggesting a direct effect of MAM on maturation of Purkinje neurons. On day 12 no difference in the number of nucleoli was found between experimental and control animals but the number of granule cells containing multiple nucleoli increased significantly. The latter suggests that the studied cell population was supplemented with less mature cells. As a result, development of Purkinje and granule cells is desynchronized and that appears to determine the secondary effect of MAM on Purkinje cell differentiation.