Aging is associated with specific impairments of learning and memory, some of which are similar
to those caused by damage to temporal or frontal lobe structures. For example, healthy older
humans, monkeys and rats all show poorer spatial, recognition and working memory, than do
their younger counterparts. Rats and monkeys do not develop age-related pathology such as
Alzheimers and Parkinsons diseases, which makes them good models for assessing functional
alterations associated with normal aging in humans. While many cellular properties of medial
temporal lobe cells appear to be intact in aging animals, age-related impairments in synaptic
function, plasticity and gene expression have been observed. Because information is represented
by activity patterns across large populations of neurons, an understanding of the neural basis of
cognitive changes in aging requires the examination of the dynamics of behaviorally-driven neural
networks. Ensemble recording experiments are described that suggest fundamental changes in
the storage and retrieval of information, as well as in high level perceptual processing in aging
hippocampal and perirhinal cortical circuits. In addition, frontal cortical correlates of working
memory are discussed. Together the evidence suggests that normative aging processes show both
cell type and region specificity, and rather than uniform deterioration, the aging brain can show
changes consistent with adaptive, compensatory processes.