Changes in Brain Adenosine — 3′5′ — Monophosphate in the Aging Rat

Abstract

Even in subjects selected as clinically healthy and free of the usual pathologies of the aged, deficits in both verbal and motor performance may be revealed by careful measurements under mild stresses such as the imposition of time limits or the introduction of new and unfamiliar material or unusual testing situations. If we accept these observations as indicative, then it would appear that the aging nervous system is likely to be most sensitively deviant in those elements which are critically involved in the dynamic responses necessary to adaptation and that the most fruitful lines of research are those which probe these elements rather than those mainly indicative of the steady state. Out of the plethora of possibilities admitted by this approach we have chosen to study the cyclic-AMP levels of the cerebral cortex of the rat. The cortex, because it appears to be involved in those higher functions which are the first to be slowed by advancing age; and the cyclic-AMP system, because it occupies a central position as a carrier information from the outside of the cell to its interior and has been implicated in the mediation of the metabolic response of the cell to an adaptive, demand.