Age-related regulation of mouse brain cortex adrenoceptors following camphor vapor exposition

The paper deals with the ability of adrenergic receptors (AR) of mouse brain cortex to be differentially regulated in response to single or multiple expositions to camphor vapor. The regulation of α- and β-adrenoceptors has been studied in young and old Balb/c-nu mice. Results confirm the decrease of total β-adrenoceptor density previously observed in untreated mice with advancing age; in addition, receptor density decreases in both young and old mice after a single exposition to camphor vapor, followed by an adaptation after multiple stimuli. The β1 , subtype is mainly responsible for density decrease in young animals, while both β1, and β2 subtypes contribute to the decrease in old mice. On the contrary, 2 subpopulation gives the major contribution to the adaptive recovery in both young and old mice. α-Adrenoceptors also show an age-related decrease in the control group; after a single exposition they show an increased density with the exception of α1-subset in the young group. Repeated expositions lead to a rather general adaptive response towards pre-stimuli conditions. The differential behaviour of receptor subtypes in response to camphor vapor exposition can be related to the differential alterations of receptor characteristics observed during aging and also suggests a possible mechanism through which these alterations may occur.