Differential expression of synaptic proteins in the frontal and temporal cortex of elderly subjects with mild cognitive impairment
Document Type
Article
Abstract
Alterations in synaptic protein stoichiometry may contribute to neocortical synaptic dysfunction in Alzheimer disease (AD). Whether perturbations in synaptic protein expression occur during the earliest stages of cognitive decline remain unclear. We examined protein levels of synaptophysin (SYP), synaptotagmin (SYT), and drebrin (DRB) in 5 neocortical regions (anterior cingulate, superior frontal, superior temporal, inferior parietal, and visual) of people clinically diagnosed with no cognitive impairment (NCI), mild cognitive impairment (MCI), mild/moderate AD, or severe AD. Normalized SYP levels were decreased approximately 35% in the superior temporal and inferior parietal cortex in severe AD compared with NCI. SYT levels were unchanged across clinical diagnosis in the cortical regions. Levels of DRB, a dendritic spine plasticity marker, were reduced approximately 40% to 60% in all cortical regions in AD compared with NCI. DRB protein was also reduced approximately 35% in the superior temporal cortex of MCI subjects, and DRB and SYP levels in the superior temporal cortex correlated with Mini-Mental State Examination and Braak scores. In contrast, DRB levels in the superior frontal cortex increased approximately 30% in MCI subjects. The differential changes in DRB expression in the frontal and temporal cortex in MCI suggest a disparity of dendritic plasticity within these regions that may contribute to the early impairment of temporal cortical functions subserving memory and language compared with the relative preservation of frontal cortical executive function during the initial stages of cognitive decline. Copyright © 2006 by the American Association of Neuropathologists, Inc.
Keywords
Alzheimer, Cortex, Drebrin, Mild cognitive impairment, Synaptic, Synaptophysin, Synaptotagmin
Publication Date
6-1-2006
Publication Title
Journal of Neuropathology and Experimental Neurology
ISSN
00223069
Volume
65
Issue
6
First Page
592
Last Page
601
PubMed ID
16783169
Digital Object Identifier (DOI)
10.1097/00005072-200606000-00007
Recommended Citation
Counts, Scott E.; Nadeem, Muhammad; Lad, Shivanand P.; Wuu, Joanne; and Mufson, Elliott J., "Differential expression of synaptic proteins in the frontal and temporal cortex of elderly subjects with mild cognitive impairment" (2006). Translational Neuroscience. 1779.
https://scholar.barrowneuro.org/neurobiology/1779