title: Exercise changes the size of cardiac neurons and protects them from age-related neurodegeneration.
abstract: Aging leads to changes in cardiac structure and function. Evidence suggests that the practice of regular exercise may prevent disturbances in the cardiovascular system during aging. We studied the effects of aging on the morphology and morphometry of cardiac neurons in Wistar rats and investigated whether a lifelong moderate exercise program could exert a protective effect toward some deleterious effects of aging. Aging caused a significant decline (28%) in the number of NADH-diaphorase-stained cardiac neurons. Animals submitted to a daily session of 60 min, 5 day/week, at 1.1 km/h of running in treadmill over the entire life span exhibited a reversion of the observed decline in the number of cardiac neurons. However, most interesting was that the introduction of this lifelong exercise protocol dramatically altered the sizes of cardiac neurons. There was a notable increase in the percentage of small neurons in the rats of the exercise group compared to the sedentary animals. This is the first time that a protective effect of lifelong regular aerobic exercise has been demonstrated on the deleterious effects of aging in cardiac neurons.
authors.affiliation: Human Movement Laboratory, São Judas Tadeu University, Taquari Street, 546 São Paulo, Brazil. efgama@mandic.com.br
authors.forename: Eliane Florencio
authors.initials: EF
authors.lastname: Gama
authors.forename: José Maria
authors.initials: JM
authors.lastname: Santarém
authors.forename: Edson Aparecido
authors.initials: EA
authors.lastname: Liberti
authors.forename: Wilson
authors.initials: W
authors.lastname: Jacob Filho
authors.forename: Romeu Rodrigues de
authors.initials: RR
authors.lastname: Souza
mesh_terms: D000375:Aging; D000818:Animals; D001835:Body Weight; D002452:Cell Count; D006321:Heart / Q000254:growth & development / Q000502:physiology* / Q000503:physiopathology; D006352:Heart Ventricles / Q000033:anatomy & histology; D008297:Male; D009410:Nerve Degeneration / Q000503:physiopathology / Q000517:prevention & control*; D009474:Neurons / Q000166:cytology / Q000502:physiology; D009929:Organ Size; D010805:Physical Conditioning, Animal / Q000502:physiology*; D005082:Physical Exertion; D051381:Rats; D017208:Rats, Wistar; D057185:Sedentary Behavior