Evidence that the loss of Purkinje cells and deep cerebellar nuclei neurons in homozygous weaver is not related to neurogenetic patterns.

To determine whether the neurogenetic patterns of Purkinje cells and deep cerebellar nuclei neurons were normal in weaver homozygotes and whether the degeneration of those neuronal types was linked to their time of origin, [3H] thymidine autoradiography was applied on sections of homozygous weaver mice and normal controls on postnatal day 90. The experimental animals were the offspring of pregnant dams injected with [3H] thymidine on embryonic days 11-12, 12-13, 13-14 and 14-15. The results show that the onset of neurogenesis, its pattern of peaks and valleys, and its total span were similar between wild type and homozygous weaver in the cerebellar areas analyzed, indicating that the loss of Purkinje cells and deep cerebellar nuclei neurons is not related to neurogenetic patterns. In weaver homozygotes, the loss of Purkinje cells and deep cerebellar nuclei neurons followed a lateral to medial gradient of increasing severity. Thus, the vermis and the fastigial nucleus, which are medially located, presented the most important neuron loss, whereas in the lateral hemisphere and the dentate nucleus, neuron loss was spared.