Environmental enrichment restores neurogenesis and rapid acquisition in aged rats.
Strategies combatting cognitive decline among the growing aging population are vital. We tested whether environmental enrichment could reverse age-impaired rapid spatial search strategy acquisition concomitantly with hippocampal neurogenesis in rats. Young (5-8 months) and aged (20-22 months) male Fischer 344 rats were pair-housed and exposed to environmental enrichment (n = 7 young, 9 aged) or housed individually (n = 7 young, 7 aged) for 10 weeks. After 5 weeks, hidden platform trials (5 blocks of 3 trials; 15 m inter-block interval), a probe trial, and then visible platform trials (5 blocks of 3 trials; 15 m inter-block interval) commenced in the water maze. One week after testing, rats were given 5 daily intraperitoneal bromodeoxyuridine (50 mg/kg) injections and perfused 4 weeks later to quantify neurogenesis. Although young rats outperformed aged rats, aged enriched rats outperformed aged individually housed rats on all behavioral measures. Neurogenesis decreased with age but enrichment enhanced new cell survival, regardless of age. The novel correlation between new neuron number and behavioral measures obtained in a rapid water maze task among aged rats, suggests that environmental enrichment increases their ability to rapidly acquire and flexibly use spatial information along with neurogenesis.
J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA.
Rachel B
RB
Speisman
Ashok
A
Kumar
Asha
A
Rani
Jessica M
JM
Pastoriza
Jamie E
JE
Severance
Thomas C
TC
Foster
Brandi K
BK
Ormerod
D000367:Age Factors; D000375:Aging; D000704:Analysis of Variance; D000818:Animals; D000941:Antigens / Q000378:metabolism; D001973:Bromodeoxyuridine / Q000378:metabolism; D002452:Cell Count; D003463:Cues; D000089622:Doublecortin Domain Proteins; D004777:Environment; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006624:Hippocampus / Q000166:cytology*; D008297:Male; D018782:Maze Learning; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D055495:Neurogenesis / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D009479:Neuropeptides / Q000378:metabolism; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D011509:Proteoglycans / Q000378:metabolism; D011597:Psychomotor Performance; D051381:Rats; D011916:Rats, Inbred F344; D013037:Spatial Behavior; D013997:Time Factors; D000099216:Chondroitin Sulfate Proteoglycan 4
D000941:Antigens; D001973:Bromodeoxyuridine; D000089622:Doublecortin Domain Proteins; D005904:Glial Fibrillary Acidic Protein; D008869:Microtubule-Associated Proteins; D009479:Neuropeptides; D010751:Phosphopyruvate Hydratase; D011509:Proteoglycans; D000099216:Chondroitin Sulfate Proteoglycan 4