Even in the absence of dementia, a dichotomy remains between successful and unsuccessful cognitive aging. The long range goal is to provide interventions to delay, prevent, or treat cognitive decline associated with unsuccessful aging in order to improve the health and well- being of older Americans. The overall hypothesis for the proposed work is that memory consolidation deficits are an early marker of cognitive decline. It is hypothesized that memory deficits result from impaired activation of NMDA receptor (NMDAR) signaling cascades that direct the expression of genes for maintaining hippocampal function. The studies will examine signaling cascades in two fields of the hippocampus (CA1 and the dentate gyrus) of rats at different ages in order to distinguish when and where changes associated with memory deficits first emerge.
Specific aim 1 will combine behavioral characterization, in vitro electrophysiology, protein and gene expression analyses to tests the hypothesis that memory consolidation deficits result from a decreased ability to activate signaling cascades that are important for memory. Preliminary data indicates that NMDAR synaptic responses and the activity of ERK is decreased in middle-aged and aged animals with memory consolidation deficits relative to aged-matched, unimpaired rats. Examination of brain tissue supports the idea that deficits are associated with a reduction in experience induced changes in chromatin structure (histone acetylation) and the expression of genes related to synaptic activity.
Specific aim 2 will test the hypothesis that neural inflammation contributes to the decline in the signaling cascade and cognitive decline. It is predicted that non-steroidal anti-inflammatory drugs (NSAIDs) will reverse the decrease in NMDAR activated signaling cascade activity and improve memory in aging animals. The same techniques and measures will be used to examine control and NSAID treated naimals. Preliminary data indicates that memory impaired animals exhibit markers of neuroinflammation observed as enhanced expression of cytokines and genes related to cellular stress and memory consolidation deficits associated with neuroinflammation can be reversed by NSAID treatment.

Public Health Relevance

Even in the absence of dementia, a dichotomy remains between successful and unsuccessful cognitive aging. The long range goal is to provide interventions to delay, prevent, or treat cognitive decline associated with unsuccessful aging in order to improve the health and well- being of older Americans

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
5R37AG036800-03
Application #
8323369
Study Section
Neurobiology of Learning and Memory Study Section (LAM)
Program Officer
Wagster, Molly V
Project Start
2010-09-30
Project End
2014-08-31
Budget Start
2012-09-01
Budget End
2013-08-31
Support Year
3
Fiscal Year
2012
Total Cost
$278,276
Indirect Cost
$81,230
Name
University of Florida
Department
Neurosciences
Type
Schools of Medicine
DUNS #
969663814
City
Gainesville
State
FL
Country
United States
Zip Code
32611
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Kumar, Ashok (2015) NMDA Receptor Function During Senescence: Implication on Cognitive Performance. Front Neurosci 9:473
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Guidi, Michael; Kumar, Ashok; Foster, Thomas C (2015) Impaired attention and synaptic senescence of the prefrontal cortex involves redox regulation of NMDA receptors. J Neurosci 35:3966-77
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Bean, Linda A; Kumar, Ashok; Rani, Asha et al. (2015) Re-Opening the Critical Window for Estrogen Therapy. J Neurosci 35:16077-93
Kumar, Ashok; Foster, Thomas C (2014) Interaction of DHPG-LTD and synaptic-LTD at senescent CA3-CA1 hippocampal synapses. Hippocampus 24:466-75

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