title: Short-term environmental enrichment enhances synaptic plasticity in hippocampal slices from aged rats.
abstract: Age-associated changes in cognition are mirrored by impairments in cellular models of memory and learning, such as long-term potentiation (LTP) and long-term depression (LTD). In young rodents, environmental enrichment (EE) can enhance memory, alter LTP and LTD, as well as reverse cognitive deficits induced by aging. Whether short-term EE can benefit cognition and synaptic plasticity in aged rodents is unclear. Here, we tested if short-term EE could overcome age-associated impairments in induction of LTP and LTD. LTP and LTD could not be induced in the CA1 region of hippocampal slices in control, aged rats using standard stimuli that are highly effective in young rats. However, exposure of aged littermates to EE for three weeks enabled successful induction of LTP and LTD. EE-facilitated LTP was dependent upon N-methyl-d-aspartate receptors (NMDARs). These alterations in synaptic plasticity occurred with elevated levels of phosphorylated cAMP response element-binding protein and vascular endothelial growth factor, but in the absence of changes in several other synaptic and cellular markers. Importantly, our study suggests that even a relatively short period of EE is sufficient to alter synaptic plasticity and molecular markers linked to cognitive function in aged animals.
authors.affiliation: Department of Psychiatry, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
authors.forename: Liana R
authors.initials: LR
authors.lastname: Stein
authors.affiliation: Department of Psychiatry, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA; The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
authors.forename: Kazuko A
authors.initials: KA
authors.lastname: O'Dell
authors.affiliation: Department of Psychiatry, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
authors.forename: Michiyo
authors.initials: M
authors.lastname: Funatsu
authors.affiliation: Department of Psychiatry, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA; The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA; Center for Brain Research in Mood Disorders, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA; Department of Neuroscience, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
authors.forename: Charles F
authors.initials: CF
authors.lastname: Zorumski
authors.affiliation: Department of Psychiatry, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA; The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA; Center for Brain Research in Mood Disorders, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA. Electronic address: izumiy@wustl.edu.
authors.forename: Yukitoshi
authors.initials: Y
authors.lastname: Izumi
mesh_terms: D000375:Aging / Q000502:physiology* / Q000523:psychology*; D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism; D056547:CA1 Region, Hippocampal / Q000502:physiology*; D000242:Cyclic AMP / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D004777:Environment; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D006799:Housing, Animal; D017774:Long-Term Potentiation / Q000502:physiology*; D036881:Long-Term Synaptic Depression / Q000502:physiology*; D008297:Male; D010766:Phosphorylation; D011897:Random Allocation; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D013997:Time Factors; D046509:Tissue Culture Techniques; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D015431:Weight Loss
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D017362:Cyclic AMP Response Element-Binding Protein; D016194:Receptors, N-Methyl-D-Aspartate; D042461:Vascular Endothelial Growth Factor A; C467498:vascular endothelial growth factor A, rat; D000242:Cyclic AMP
keywords: N-methyl-d-aspartate receptor; aging; environmental enrichment; long-term depression; long-term potentiation