title: Aging increases basal but not stress-induced levels of corticosterone in the brain of the awake rat.
abstract: The main purpose of this study was to evaluate the effect of aging on plasma and free corticosterone (CORT) levels in the brain in basal conditions and in response to an acute stressor. Microdialysis experiments were performed in the hippocampus (HC) and the prefrontal cortex (PFC) of young adult (6 months) and aged (24 months) male Wistar rats. Basal free levels of CORT in the HC and the PFC were higher in aged animals. Restraint stress increased plasma CORT and free CORT levels in the HC and the PFC both in young and aged animals. However, while the increase of plasma CORT was higher in aged rats compared with young rats, the increases of free CORT in the HC and the PFC were not different between these two groups of rats. These results suggest that the changes produced by aging in the brain may be related to the enhanced basal levels of free CORT and not to the CORT increases in response to stress.
authors.affiliation: Department of Physiology, Faculty of Medicine, Universidad Complutense, Madrid, Spain. pgarrido@med.ucm.es
authors.forename: Pedro
authors.initials: P
authors.lastname: Garrido
authors.forename: Marta
authors.initials: M
authors.lastname: de Blas
authors.forename: Alberto
authors.initials: A
authors.lastname: Del Arco
authors.forename: Gregorio
authors.initials: G
authors.lastname: Segovia
authors.forename: Francisco
authors.initials: F
authors.lastname: Mora
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D003345:Corticosterone / Q000378:metabolism*; D006624:Hippocampus / Q000378:metabolism*; D008297:Male; D017397:Prefrontal Cortex / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013315:Stress, Psychological / Q000378:metabolism*; D014018:Tissue Distribution; D015854:Up-Regulation; D014851:Wakefulness
chemical_list: D003345:Corticosterone