Influence of ipsilateral lesions of the nucleus basalis magnocellularis and of choline alphoscerate treatment on histochemically reactive zinc stores and on the ultrastructure of the rat frontal cortex.

The influence of ipsilateral lesions of the nucleus basalis magnocellularis (NBM) and of choline alphoscerate treatment on histochemically reactive zinc stores and on the ultrastructure of the neuropil of layer III of the frontal cortex were investigated in the rat. In control animals a dark-brown staining was developed in the neuropil of layers I-III of the frontal cortex. Lesions of the right NBM caused a marked reduction in the density of sulphide-silver staining in the right frontal cortex 4 weeks post lesion. Moreover, changes in the morphology and in the density of synaptic buttons in the neuropil of layer III of the cerebral cortex were also noticeable. Concomitant treatment for 4 weeks with choline alphoscerate restored the density of sulphide-silver staining in the right frontal cortex and countered in part changes of synaptic buttons of the neuropil of layer III of the frontal cortex. These findings suggest that the loss of cerebrocortical histochemically reactive zinc stores occurring in NBM-lesioned rats is due to the alterations of synaptic contacts in the frontal cortex and that treatment with choline alphoscerate may counter these degenerative changes.