Auteur / Autrice : | Jérémy Terrien |
Direction : | Fabienne Aujard |
Type : | Thèse de doctorat |
Discipline(s) : | Biologie du vieillissement |
Date : | Soutenance en 2009 |
Etablissement(s) : | Paris 5 |
Mots clés
Mots clés contrôlés
Résumé
Age-related deteriorations in the effector mechanisms of thermoregulation may threaten the maintenance of homeostasis. This hypothesis was tested in a primate, the gray mouse lemur (Microcebus murinus), during thermal challenges. The season has emerged as a dominant parameter. During summer, aging did not impair normothermia and energy balance maintenance. However, age-related impairments were demonstrated in winter in response to low or high Ta. Indeed, daily Tc rhythms were widely depth during cold exposure and associated with negative energy balance. When exposed to heat, aged individuals exhibited reduced capacities to dissipate body. Age-related impairments in IGF-1 signalling have also been demonstrated. To conclude, aging was strongly associated in mouse lemurs with impaired control of Tc levels, with different levels according to season.