title: Effects of electrical stimulation and norepinephrine on cyclic-AMP levels in the cerebral cortex of the aging rat.
abstract: One to 24 month old rats were anesthetized with alpha-chloralose, their cerebral cortices exposed surgically and subjected in vivo to stimulation by norepinephrine (1.0mM for 5 minutes) or electrical pulses (100 pulses/s for 10 s). After microwave fixation, cortical samples were analyzed for cyclic-AMP by the Gilman method. In similarly prepared but unstimulated control animals, cyclic-AMP levels were found to be three to four-fold lower in older than in younger rats, a pattern previously reported for unanesthetized rats. Both norepinephrine and electrical pulses led to cyclic AMP increases. With increasing age the cyclic-AMP levels attained under both stimulus conditions declined, with the levels achieved in the two cases becoming increasingly divergent.
mesh_terms: D000375:Aging; D000771:Anesthesia, Intravenous; D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D002698:Chloralose / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism*; D004558:Electric Stimulation; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology*; D051381:Rats; D013268:Stimulation, Chemical
chemical_list: D002698:Chloralose; D000242:Cyclic AMP; D009638:Norepinephrine