The effect of thyroid hormone on the formation of rat cerebellar Bergmann-glia.

H3-thymidine incorporating cells were demonstrated by autoradiography in the developing cortex. Before the 7-8th days labelled cells were distributed throughout the full width of the internal granular layer. Between days 8 to 14 they were found exclusively in the ganglionic layer and were identified as Bergmann-glia. Thyroid hormone treatment brought about an earlier shift of the label to the ganglionic layer indicating an acceleration of Bergmann-glia formation. Since the acceleration coincided with the known accelerating effect of thyroid hormone on granule cell migration, a causal relationship is assumed between Bergmann-glia formation and granula cell migration.