About this item:

56 Views | 31 Downloads

Author Notes:

Corresponding author: Jeremy H. Herskowitz, Ph.D. Center for Neurodegeneration and Experimental Therapeutics, Departments of Neurology and Neurobiology, University of Alabama at Birmingham, 1825 University Blvd., Birmingham, AL, 35294, Phone: 205.996.6257, jhersko@uab.edu.

J.H.H., B.D.B., and M.G. conceived the experiments; B.D.B., K.M.G., E.G.G., K.A.C., E.L.B., M.G., and J.H.H. performed the experiments and analyzed the data; and B.D.B. and J.H.H. wrote the article.

We thank Drs. Sharon Swanger and Linda Overstreet-Wadiche for critical reading of this manuscript and acknowledge Dr. Yaakov Stern for constructive discussions.

Potential Conflicts of Interests: Nothing to report.

Subjects:

Research Funding:

This work was supported by the National Institutes of Health through NIA AG054719 to J.H.H. and NIA AG043552-05 to J.H.H., Emory Neuroscience NINDS Core Facilities grant P30NS055077, and the Emory University Alzheimer’s Disease Research Center grant AG025688. Additional support stemmed from a New Investigator Research Grant 2015-NIRG-339422 to J.H.H. from the Alzheimer’s Association.

Keywords:

  • Science & Technology
  • Life Sciences & Biomedicine
  • Clinical Neurology
  • Neurosciences
  • Neurosciences & Neurology
  • PREFRONTAL CORTEX
  • NEUROPATHOLOGIC ASSESSMENT
  • NATIONAL INSTITUTE
  • SYNAPSE LOSS
  • IMPAIRMENT
  • DEMENTIA
  • PLASTICITY
  • GUIDELINES
  • CORRELATE
  • MONKEY

Dendritic spines provide cognitive resilience against Alzheimer's disease

Journal Title:

Annals of Neurology

Volume:

Volume 82, Number 4

Publisher:

, Pages 602-614

Type of Work:

Article | Post-print: After Peer Review

Abstract:

Objective: Neuroimaging and other biomarker assays suggest that the pathological processes of Alzheimer's disease (AD) begin years prior to clinical dementia onset. However, some 30 to 50% of older individuals who harbor AD pathology do not become symptomatic in their lifetime. It is hypothesized that such individuals exhibit cognitive resilience that protects against AD dementia. We hypothesized that in cases with AD pathology, structural changes in dendritic spines would distinguish individuals who had or did not have clinical dementia. Methods: We compared dendritic spines within layer II and III pyramidal neuron dendrites in Brodmann area 46 dorsolateral prefrontal cortex using the Golgi–Cox technique in 12 age-matched pathology-free controls, 8 controls with AD pathology (CAD), and 21 AD cases. We used highly optimized methods to trace impregnated dendrites from bright-field microscopy images that enabled accurate 3-dimensional digital reconstruction of dendritic structure for morphologic analyses. Results: Spine density was similar among control and CAD cases but was reduced significantly in AD. Thin and mushroom spines were reduced significantly in AD compared to CAD brains, whereas stubby spine density was decreased significantly in CAD and AD compared to controls. Increased spine extent distinguished CAD cases from controls and AD. Linear regression analysis of all cases indicated that spine density was not associated with neuritic plaque score but did display negative correlation with Braak staging. Interpretation: These observations provide cellular evidence to support the hypothesis that dendritic spine plasticity is a mechanism of cognitive resilience that protects older individuals with AD pathology from developing dementia. Ann Neurol 2017;82:602–614.

Copyright information:

© 2017 American Neurological Association

Export to EndNote