Brain cell alterations suggesting premature aging induced by dietary deficiency of vitamin B6 and/or copper.

Weanling albino rats were fed semisynthetic diets deficient or sufficient in vitamin B6 or copper, or both, for 2 or 3 months. Brains were examined by light and electron microscopy after Golgi impregnation or conventional tissue processing for electron microscopy. Golgi impregnation revealed that some pyramidal cells of the cerebral cortex, particularly in layers III and V, showed partial to nearly complete dendritic loss. This occurred in all deficient groups but was most typical of deficiency of vitamin B6. Swelling in dendrites or perikarya was more typical of copper deficiency. Ultrastructural observation revealed large vacuoles in cellular processes of the cerebral cortex in deficient groups. The hippocampus of copper-deficient rats contained dark, apparently degenerating processes while axonal swellings were seen in vitamin B6 deficiency. These abnormalities are discussed as evidence for accelerated aging of neurons related to poor nutritional status.