Effect of chronic vitamin E deficiency on the synapses of cerebellar glomeruli in young rats.

A morphometric investigation has been carried out on the synaptic junctions in the cerebellar glomeruli of young-adult rats chronically deprived of vitamin E for 10 months and control animals of the same age. The following parameters were evaluated: the average length of the synapses (L), the numerical (NV) as well as the surface (SV) density of the synaptic contact zones. The results from these experimental groups were compared with data from young, adult and old rats. The results obtained show a significant decrease of the surface density of the synaptic contact zones in old and alpha-tocopherol deprived young-adult (11-month-old) rats as compared to younger and normally fed animals. This reduction of the synaptic contact area seems to be due to the marked decline in the number of synapses found in both cases. The average size (L) of the synaptic junctions, on the other hand, was increased in alpha-tocopherol deficient rats as compared to normally fed littermates. The significant reduction of the synaptic contact area in old and vitamin E deprived young rats supports the hypothesis that a common denominator may be responsible to explain this alteration. Because of the recognized protective role of alpha-tocopherol against free radical attacks on plasma membranes, the present findings support an involvement of membrane structural alterations in aging as well as in vitamin E deficiency.