Models of aging of neuroimmunomodulation: strategies for its improvement.

Communication between the nervous and the immune systems suffers impairment with aging, which explains the altered homeostasis and the resulting increase of morbidity and mortality in aged subjects. In humans, rats and specially in mice, we have proposed several models to study this fact. The established models of premature aging have been mice and humans with poor response to stress and anxiety versus subjects of the same chronological age without that characteristic, isolation, males versus females, menopausal models (in rodents after ovariectomy) and obesity. In all cases, the prematurely aged animals suffer an alteration of the nervous system (shown by behavioral tests) and immunosenescence as well as oxidative and inflammatory stress, which is followed by early mortality. In addition, in the above-mentioned models and in normal chronological aging, we have observed the effect of several lifestyle strategies, such as ingestion of adequate amounts of antioxidants, performance of moderate physical exercise, and different kinds of environmental enrichment, which improve the function of the immune cells and their redox state as well as animal behavior. Therefore, they retard the aging process and seem to increase the longevity of the individuals.