BDNF and chronic lung disease: Furthermore, in animal studies, enriched environments (characterized by novel stimuli; analogous to the accumulation of CR in humans) (47), contribute to improving neural plasticity and neuroendocrine function (48), increasing levels of brain-derived neurotrophic factor, counterbalancing immune response, and reducing inflammation (49) and oxidative stress (50), which all play a protective role against the development of cardio-cerebral vascular disease, endocrine metabolic disease, cognitive impairment, chronic lung disease, and cancer (13–16).