Uptake of 3H-norepinephrine in the cerebral hemispheres and cerebellum of the chicken throughout the lifespan

Abstract

The uptake of 3H-norepinephrine ( 3H-NE) was studied from slices of cerebral hemispheres and cerebellum removed from chick embryos and from chicks at various ages after hatching up to 3 years. In the cerebral hemispheres accumulation of 3H-NE markedly and progressively increased from 10 days of embryonic age up to 3 months after hatching, remained at this level up to 1 year and progressively declined thereafter and by 3 years, reached that of embryonic levels. In contrast, 3H-NE accumulation in the cerebellum reached a high level by 20 days of embryonic age and remained at this level until 3 years posthatching. Cocaine (an inhibitor of neuronal uptake mechanisms) markedly inhibited accumulation of 3H-NE in both central nervous system (CNS) tissues at all ages studied. Reserpine (an inhibitor of uptake of NE into storage granules) inhibited accumulation of NE in the cerebral hemispheres after 15 days of embryonic age; whereas in the cerebellum inhibition of 3H-NE accumulation by reserpine was present at 15 days of embryonic age. It appears from these findings that with aging noradrenergic function declines in the cerebral hemispheres whereas it remains active in the cerebellum.