Memory dysfunction is the most common complaint of the elderly but this problem is difficult to study since there are a number of factors contributing to age-related changes in memory. Two of these factors will be the focus of the proposed studies: 1) normal healthy age-related changes that occur in the anatomy and physiology of the brain throughout the life span that mediate the natural unfolding of different cognitive strategies (e.g., verbal mediation/abstraction) and 2) two pathological processes (e.g., hypertension and type 2 diabetes) that often accompany normal aging. One goal is to separate healthy "successful" aging from "normal" aging, respectively, since vascular and metabolic disorders also target prefrontal cortex and result in increased risk for cognitive decline and dementia, including Alzheimer's disease. This is important since hypertension and type 2 diabetes can be controlled or prevented. For heuristic purposes, aging will be considered from both a "traditional" view which suggests there is an inevitable loss of tissues and functional reserves across age and an alternative "systems" view that focuses on the maturation and degeneration of white matter (WM) tracts, which provide the mechanism for efficient communication between brain regions. We propose to use magnetoencephalography or MEG to examine visual episodic memory function with and without distracters, along with diffusion tensor imaging (DTI), MR morphometry, and neuropsychological tests to investigate links between: 1) WM integrity and system connectivity which are necessary for the development of higher cognitive functions;and 2) WM pathology and memory performance degradation. A demonstration of optimal activation of frontoparietal circuits with maturation and inactivation due to disease will highlight the importance of WM tracts for effective top-down strategies such as verbal mediation/abstraction. Healthy participants from three age groups will be examined to characterize the development of cognitive control and consequent changes in brain activation patterns in adulthood (18-25, 35-45, ? 65 years). A group of middle-aged subjects with 1) hypertension and 2) type 2 diabetes, along with a group of elderly with hypertension will also be examined, thus resulting in 6 groups of 30 individuals each. The patterns of correlations witnessed between MEG response profiles localized to specific cortical regions and DTI/neuropsychological test results will help characterize the functions of these brain regions while subjects were engaged in the memory tasks. Morphometric and DTI analyses will provide independent measures of whether the young are still maturing (in which case the middle-aged group should perform best and have higher WM volumes in prefrontal cortex) or whether there is a linear decline in gray and WM volumes and performance across age (i.e., systems vs traditional views of aging, respectively). This proposal will demonstrate that healthy successful aging does not necessarily lead to memory dysfunction. Instead, recent evidence indicates that vascular and metabolic disorders such as hypertension and type 2 diabetes target prefrontal cortex and result in increased risk for cognitive decline and dementia, including Alzheimer's disease. This research is important because much cognitive decline can be prevented if Americans are made aware that good physical health can help reduce the risk of developing dementia later in life.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Project (R01)
Project #
5R01AG029495-05
Application #
8317611
Study Section
Special Emphasis Panel (ZRG1-IFCN-E (02))
Program Officer
Wagster, Molly V
Project Start
2008-09-15
Project End
2014-08-31
Budget Start
2012-09-01
Budget End
2014-08-31
Support Year
5
Fiscal Year
2012
Total Cost
$429,994
Indirect Cost
$87,687
Name
University of New Mexico
Department
Radiation-Diagnostic/Oncology
Type
Schools of Medicine
DUNS #
868853094
City
Albuquerque
State
NM
Country
United States
Zip Code
87131
Josef Golubic, Sanja; Aine, Cheryl J; Stephen, Julia M et al. (2014) Modulatory role of the prefrontal generator within the auditory M50 network. Neuroimage 92:120-31
Aine, C J; Sanfratello, L; Adair, J C et al. (2014) Characterization of a normal control group: are they healthy? Neuroimage 84:796-809
Aine, C J; Sanfratello, L; Ranken, D et al. (2012) MEG-SIM: a web portal for testing MEG analysis methods using realistic simulated and empirical data. Neuroinformatics 10:141-58
Aine, C J; Sanfratello, L; Adair, J C et al. (2011) Development and decline of memory functions in normal, pathological and healthy successful aging. Brain Topogr 24:323-39
Shoemaker, J M; Holdsworth, M T; Aine, C et al. (2011) A practical approach to incidental findings in neuroimaging research. Neurology 77:2123-7
Aine, C J; Bryant, J E; Knoefel, J E et al. (2010) Different strategies for auditory word recognition in healthy versus normal aging. Neuroimage 49:3319-30
Stephen, Julia M; Knoefel, Janice E; Adair, John et al. (2010) Aging-related changes in auditory and visual integration measured with MEG. Neurosci Lett 484:76-80