Cytochemical variations in Purkinje neuron nuclei of cerebellar areas with different afferent systems in Rana esculenta. Comparison between activity and hibernation.

The distribution pattern of the Feulgen-DNA values (nuclear cytochemical heterogeneity) which provides information on the functional state of Purkinje neurons was investigated in the lobus vestibularis and in the corpus cerebelli in active and hibernating frogs. In the corpus cerebelli, hibernation does not change greatly the nuclear heterogeneity of Purkinje neurons, while in the lobus vestibularis this neuron population becomes more homogeneous and shows more condensed chromatin. These data suggest a nerve conduction in the two areas which responds differently to the phenomenon of hibernation, entailing a lower activity of Purkinje neurons in the lobus vestibularis with respect to the corpus cerebelli. Furthermore, the examination of a portion of the vestibular nuclear complex revealed an opposite behavior: indeed, a higher homogeneity of the nuclear cytochemical patterns was observed during activity. This result is related to the function of this localization as center of stimuli integration.