Vitamin E deficiency and aging effect on expression levels of GAP-43 and MAP-2 in selected areas of the brain.

The expression levels of GAP-43 and MAP-2, two proteins involved, respectively, in axonal and dendritic remodeling, in control adult (11 months), old (24 months), and vitamin E-deficient (11 months) rats were evaluated. mRNA levels were determined by means of a quantitative in situ hybridization procedure in subregions of hippocampus and cerebellum. Though a general trend can be observed indicating a reduction in GAP-43 expression in aging as compared to adult animals and an increase in vitamin E-deprived rats in comparison with adult animals, no statistically significant change was found in any region analyzed. In the same way, MAP-2 mRNA levels show an increase in vitamin E-deprived rats in comparison with other groups tested; only one variation was statistically significant, namely the increase in cerebellar cortex MAP-2 nRNA levels in vitamin E-deficient versus adult rats. These results suggest that oxidative stress and aging negatively affect neuroplasticity, showing different characteristics at the dendritic and axonal levels.