ABSTRACT
The hippocampus is an anatomical region that is critical for certain types of learning and memory that are vulnerable to the effects of normal aging. This chapter discusses the age-related deficits in signal transduction do occur and are presumed to reflect deficient transfer of information both within the hippocampal formation and between the hippocampus and other brain structures critical for proper cognitive function. Animals are initially behaviorally characterized to provide a measure of hippocampal function and, subsequently, the hippocampus and related structures are dissected and examined for changes in the machinery necessary for proper signaling within and between neurons. The quantification of the availability of key proteins involved in the second messenger signal transduction cascade is an essential first step in investigating this signaling pathway as a causative factor in age-related cognitive decline. Studies in behaviorally characterized aged rat have demonstrated that decrements in muscarinic and metabotropic glutamate receptor function in the hippocampus are related to cognitive impairment.
