ABSTRACT
Age-related changes of neurofilament proteins and unwinded DNA have been studied in the neuronal preparations from rat brain. The relative integrity of the cells was confirmed by lactate dehydrogenase [LDH] latency which was similar for all ages [3 days, 3 months and 30 months] studied. The concentrations of neurofilaments was measured by quantitative enzyme-linked immunosorbent assay [ELISA]. The neurofilament content of neurons increased during development of rat brain and decreased in the neuronal preparations of aged rat. Whereas the amount of unwinded DNA increased only in the neurons of aged animals. The opposite relationship between the amount of unwinded DNA and the neurofilament content of the neurons in aging is consistent with the susceptibility of the neurons to the metabolic alterations of the aging process. It is suggested that the decrease of the neurofilament content of the neurons may be a causative factor of neuronal loss in aging