Lifespan trajectory of myelin integrity and maximum motor speed

NEUROBIOLOGY OF AGING

卷:31

Article

Bartzokis, George^1,2,3  Mendez, Mario F.³  Richard, Aurore¹  Peters, Douglas G.¹  Oluwadara, Bolanle¹  Barrall, Katherine A.³  Finn, J. Paul⁴  Villablanca, Pablo⁴  Thompson, Paul M.²  Mintz, Jim⁵ 

[1] Univ Calif Los Angeles, David Geffen Sch Med, Dept Psychiat & Biobehav Sci, Los Angeles, CA 90024 USA

[2] Univ Calif Los Angeles, David Geffen Sch Med, Dept Neurol, Lab Neuroimaging,Div Brain Mapping, Los Angeles, CA 90095 USA

[3] Greater Los Angeles VA Healthcare Syst, Dept Psychiat, Los Angeles, CA 90073 USA

[4] Univ Calif Los Angeles, David Geffen Sch Med, Dept Radiol, Los Angeles, CA 90095 USA

[5] Univ Texas Hlth Sci Ctr San Antonio, Dept Psychiat, San Antonio, TX 78229 USA

关键词: Age;    Processing speed;    Motor;    White matter;    Oligodendrocyte;    Breakdown;    Cognition;    Dementia;    Risk;    Neurodegeneration;    Alzheimer;    Onset;    Frontal lobe;    Treatment;    Prevention;   

DOI  :  10.1016/j.neurobiolaging.2008.08.015

来源: Elsevier

【 摘 要 】

Objective Myelination of the human brain results in roughly quadratic trajectories of myelin content and integrity, reaching a maximum in mid-life and then declining in older age This trajectory is most evident in vulnerable later myelinating association regions such as frontal lobes and may be the biological substrate for similar trajectories of cognitive processing speed Speed of movement, such as maximal finger tapping speed (FTS), requires high-frequency action potential (AP) bursts and is associated with myelin integrity We tested the hypothesis that the age-related trajectory of FTS is related to brain myelin integrity Methods A sensitive in VIVO MRI biomarker of myelin integrity (calculated transverse relaxation rates (R-2)) of frontal lobe white matter (FLwm) was measured in a sample of very healthy males (N=72) between 23 and 80 years of age To assess specificity. R, of a contrasting early-myelinating region (splenium of the corpus callosum) was also measured Results FLwm R-2 and FTS measures were significantly correlated (r=45, p<0001) with no association noted in the early-myelinating region (splenium) Both FLwm R-2 and FTS had significantly quadratic lifespan trajectories that were virtually indistinguishable and both reached a peak at 39 years of age and declined with an accelerating trajectory thereafter Conclusions The results suggest that in this very healthy male sample, maximum motor speed requiring high-frequency AP burst may depend on brain myelin integrity To the extent that the FLwm changes assessed by R-2 contribute to an age-related reduction in AP burst frequency, it is possible that other brain functions dependent on AP bursts may also he affected Non-invasive measures of myelin integrity together with testing of basic measures of processing speed may aid in developing and targeting anti-aging treatments to mitigate age-related functional declines (C) 2008 Elsevier Inc All rights reserved

【 授权许可】

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