title: Advanced age dissociates dual functions of the perirhinal cortex.
abstract: The perirhinal cortex (PRC) is proposed to both represent high-order sensory information and maintain those representations across delays. These cognitive processes are required for recognition memory, which declines during normal aging. Whether or not advanced age affects the ability of PRC principal cells to support these dual roles, however, is not known. The current experiment recorded PRC neurons as young and aged rats traversed a track. When objects were placed on the track, a subset of the neurons became active at discrete locations adjacent to objects. Importantly, the aged rats had a lower proportion of neurons that were activated by objects. Once PRC activity patterns in the presence of objects were established, however, both age groups maintained these representations across delays up to 2 h. These data support the hypothesis that age-associated deficits in stimulus recognition arise from impairments in high-order stimulus representation rather than difficulty in sustaining stable activity patterns over time.
authors.affiliation: Evelyn F. McKnight Brain Institute, Arizona Research Laboratories Division of Neural Systems Memory and Aging, and Departments of Psychology, Neurology and Neuroscience, University of Arizona, Tucson, Arizona 85724.
authors.forename: Sara N
authors.initials: SN
authors.lastname: Burke
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Maurer
authors.forename: Saman
authors.initials: S
authors.lastname: Nematollahi
authors.forename: Ajay
authors.initials: A
authors.lastname: Uprety
authors.forename: Jenelle L
authors.initials: JL
authors.lastname: Wallace
authors.forename: Carol A
authors.initials: CA
authors.lastname: Barnes
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D004594:Electrophysiology; D008297:Male; D008568:Memory / Q000502:physiology*; D051381:Rats; D011916:Rats, Inbred F344; D021641:Recognition, Psychology / Q000502:physiology*