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. 2003 Nov 25;100(24):14504-9.
doi: 10.1073/pnas.2235925100. Epub 2003 Nov 7.

Functional deactivations: change with age and dementia of the Alzheimer type

Cindy Lustig  1 , Abraham Z Snyder, Mehul Bhakta, Katherine C O'Brien, Mark McAvoy, Marcus E Raichle, John C Morris, Randy L Buckner
Affiliations

Functional deactivations: change with age and dementia of the Alzheimer type

Cindy Lustig et al. Proc Natl Acad Sci U S A. .

Abstract

Young adults typically deactivate specific brain regions during active task performance. Deactivated regions overlap with those that show reduced resting metabolic activity in aging and dementia, raising the possibility of a relation. Here, the magnitude and dynamic temporal properties of these typically deactivated regions were explored in aging by using functional MRI in 82 participants. Young adults (n = 32), older adults without dementia (n = 27), and older adults with early-stage dementia of the Alzheimer type (DAT) (n = 23) were imaged while alternating between blocks of an active semantic classification task and a passive fixation baseline. Deactivation in lateral parietal regions was equivalent across groups; in medial frontal regions, it was reduced by aging but was not reduced further by DAT. Of greatest interest, a medial parietal/ posterior cingulate region showed differences between young adults and older adults without dementia and an even more marked difference with DAT. The temporal profile of the medial parietal/posterior cingulate response suggested that it was initially activated by all three groups, but the response in young adults quickly reversed sign, whereas DAT individuals maintained activation throughout the task block. Exploratory whole-brain analyses confirmed the importance of medial parietal/posterior cingulate cortex differences in aging and DAT. These results introduce important opportunities to explore the functional properties of regions showing deactivations, how their dynamic functional properties relate to their baseline metabolic rates, and how they change with age and dementia.

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Figures

Fig. 1.
Fig. 1.
Regional analyses showing effects of age and dementia. (Left) Regions are projected onto an inflated representation of the cortex (40) and include left frontal cortex BA 44/6 (A), right lateral parietal cortex BA 40 (B), medial frontal cortex BA 10 (C), and medial parietal/posterior cingulate cortex BA 31 (D). References to specific BAs are tentative and used as a heuristic based on ref. . Mean magnitude estimates with standard error bars for activity in each region for each group are shown in Center, followed by the mean time courses of blood oxygenation level-dependent signal across active task and passive fixation baseline conditions for each group in Right. Note reversed sign of net response and altered time course in the posterior cingulate region (D).
Fig. 2.
Fig. 2.
Statistical activation maps for young, old, and DAT groups. Warm colors (red, yellow) show positive activations; cool colors (blues) show deactivations. Brighter colors indicate areas of greater statistical significance. (Upper) The left lateral cortical surface for each group. (Lower) The right medial surface. These maps complement the a priori statistical analyses shown in Fig. 1. Because different numbers of subjects contribute to each of the maps in the current figure, apparent differences in z scores across the groups should not be quantitatively interpreted.
Fig. 3.
Fig. 3.
Map of statistically significant group differences across the brain. Brighter colors indicate areas of greater statistical significance. Note that the medial parietal/posterior cingulate cortex showing large group differences here overlaps heavily with the BA 31 region showing robust group differences in the a priori analyses (compare with Fig. 1D).
See this image and copyright information in PMC

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References

    1. Reuter-Lorenz, P. A. (2002) Trends Cognit. Neurosci. 6, 394-400. - PubMed
    1. Grady, C. L., McIntosh, A. R., Beig, S., Keightley, M. L., Burian, H. & Black, S. E. (2003) J. Neurosci. 23, 986-993. - PMC - PubMed
    1. Cabeza, R. (2002) Psychol. Aging 17, 85-100. - PubMed
    1. Gusnard, D. A. & Raichle, M. E. (2001) Nat. Rev. Neurosci. 2, 685-694. - PubMed
    1. Mazoyer, B., Zago, L., Mellet, E., Bricogne, S., Etard, O., Houde, O., Crivello, F., Joliot, M., Petit, L. & Tzourio-Mazoyer, N. (2001) Brain Res. Bull. 54, 287-298. - PubMed

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