title: Influence of late-life exposure to environmental enrichment or exercise on hippocampal function and CA1 senescent physiology.
abstract: Aged (20-22 months) male Fischer 344 rats were randomly assigned to sedentary (A-SED), environmentally-enriched (A-ENR), or exercise (A-EX) conditions. After 10-12 weeks of differential experience, the 3 groups of aged rats and young sedentary controls were tested for physical and cognitive function. Spatial discrimination learning and memory consolidation, tested on the water maze, were enhanced in environmentally-enriched compared with sedentary. A-EX exhibited improved and impaired performance on the cue and spatial task, respectively. Impaired spatial learning in A-EX was likely due to a bias in response selection associated with exercise training, as object recognition memory improved for A-EX rats. An examination of senescent hippocampal physiology revealed that enrichment and exercise reversed age-related changes in long-term depression (LTD) and long-term potentiation (LTP). Rats in the enrichment group exhibited an increase in cell excitability compared with the other 2 groups of aged animals. The results indicate that differential experience biased the selection of a spatial or a response strategy and factors common across the 2 conditions, such as increased hippocampal activity associated with locomotion, contribute to reversal of senescent synaptic plasticity.
authors.affiliation: Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL 32610-0244, USA.
authors.forename: Ashok
authors.initials: A
authors.lastname: Kumar
authors.forename: Asha
authors.initials: A
authors.lastname: Rani
authors.forename: Olga
authors.initials: O
authors.lastname: Tchigranova
authors.forename: Wei-Hua
authors.initials: WH
authors.lastname: Lee
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Foster
mesh_terms: D000367:Age Factors; D000375:Aging / Q000502:physiology*; D000447:Aldehydes / Q000378:metabolism; D000704:Analysis of Variance; D000818:Animals; D001703:Biophysics; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism; D056547:CA1 Region, Hippocampal / Q000502:physiology*; D003463:Cues; D004192:Discrimination, Psychological; D004558:Electric Stimulation; D004777:Environment; D005786:Gene Expression Regulation / Q000502:physiology; D005979:Glutathione Peroxidase / Q000378:metabolism; D066298:In Vitro Techniques; D017774:Long-Term Potentiation / Q000502:physiology; D036881:Long-Term Synaptic Depression / Q000502:physiology; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D018782:Maze Learning; D008568:Memory / Q000502:physiology; D053580:Muscle Strength; D018408:Patch-Clamp Techniques; D010805:Physical Conditioning, Animal; D011597:Psychomotor Performance; D051381:Rats; D011916:Rats, Inbred F344; D018709:Statistics, Nonparametric; D013482:Superoxide Dismutase / Q000378:metabolism; D000072105:Superoxide Dismutase-1; D000094765:Glutathione Peroxidase GPX1
chemical_list: D000447:Aldehydes; D019208:Brain-Derived Neurotrophic Factor; D008315:Malondialdehyde; D005979:Glutathione Peroxidase; C000606292:Sod1 protein, rat; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1; C027576:4-hydroxy-2-nonenal; D000094765:Glutathione Peroxidase GPX1; C000722069:Gpx1 protein, rat