title: Age-related impairments in object-place associations are not due to hippocampal dysfunction.
abstract: Age-associated cognitive decline can reduce an individual's quality of life. As no single neurobiological deficit can account for the wide spectrum of behavioral impairments observed in old age, it is critical to develop an understanding of how interactions between different brain regions change over the life span. The performance of young and aged animals on behaviors that require the hippocampus and cortical regions to interact, however, has not been well characterized. Specifically, the ability to link a spatial location with specific features of a stimulus, such as object identity, relies on the hippocampus, perirhinal and prefrontal cortices. Although aging is associated with dysfunction in each of these brain regions, behavioral measures of functional change within the hippocampus, perirhinal and prefrontal cortices in individual animals are often not correlated. Thus, how dysfunction of a single brain region within this circuit, such as the hippocampus, impacts behaviors that require communication with the perirhinal and prefrontal cortices remains unknown. To address this question, young and aged rats were tested on the interregion dependent object-place paired association task, as well as a hippocampal-dependent test of spatial reference memory. This particular cohort of aged rats did not show deficits on the hippocampal-dependent task, but were significantly impaired at acquiring object-place associations relative to young. These data suggest that behaviors requiring functional connectivity across different regions of the memory network may be particularly sensitive to aging, and can be used to develop models that will clarify the impact of systems-level dysfunction in the elderly.
authors.affiliation: McKnight Brain Institute, Department of Neuroscience, University of Florida.
authors.forename: Abigail R
authors.initials: AR
authors.lastname: Hernandez
authors.affiliation: McKnight Brain Institute, Department of Neuroscience, University of Florida.
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Maurer
authors.affiliation: McKnight Brain Institute, Department of Neuroscience, University of Florida.
authors.forename: Jordan E
authors.initials: JE
authors.lastname: Reasor
authors.affiliation: McKnight Brain Institute, Department of Neuroscience, University of Florida.
authors.forename: Sean M
authors.initials: SM
authors.lastname: Turner
authors.affiliation: McKnight Brain Institute, Department of Neuroscience, University of Florida.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Barthle
authors.affiliation: McKnight Brain Institute, Department of Neuroscience, University of Florida.
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Johnson
authors.affiliation: McKnight Brain Institute, Department of Neuroscience, University of Florida.
authors.forename: Sara N
authors.identifier: 0000-0002-1773-1294
authors.initials: SN
authors.lastname: Burke
mesh_terms: D000367:Age Factors; D000818:Animals; D003071:Cognition; D000066492:Cognitive Aging / Q000502:physiology*; D006624:Hippocampus / Q000503:physiopathology*; D007858:Learning / Q000502:physiology; D008297:Male; D018782:Maze Learning; D008568:Memory / Q000502:physiology; D011788:Quality of Life; D051381:Rats; D021641:Recognition, Psychology / Q000502:physiology; D013028:Space Perception; D013037:Spatial Behavior; D065854:Spatial Navigation / Q000502:physiology*