NotesFAQContact Us
Collection
Advanced
Search Tips
Peer reviewed Peer reviewed
Direct linkDirect link
ERIC Number: EJ1002027
Record Type: Journal
Publication Date: 2013-Feb
Pages: 8
Abstractor: As Provided
Reference Count: 0
ISBN: N/A
ISSN: ISSN-0278-2626
Myelin Breakdown Mediates Age-Related Slowing in Cognitive Processing Speed in Healthy Elderly Men
Lu, Po H.; Lee, Grace J.; Tishler, Todd A.; Meghpara, Michael; Thompson, Paul M.; Bartzokis, George
Brain and Cognition, v81 n1 p131-138 Feb 2013
Background: To assess the hypothesis that in a sample of very healthy elderly men selected to minimize risk for Alzheimer's disease (AD) and cerebrovascular disease, myelin breakdown in late-myelinating regions mediates age-related slowing in cognitive processing speed (CPS). Materials and methods: The prefrontal lobe white matter and the genu of the corpus callosum myelinate later in brain development (late-myelinating white matter; LMWM) and are more vulnerable to breakdown due to the effects of normal aging. An "in vivo" MRI biomarker of myelin integrity (transverse relaxation rates; R[subscript 2]) of LMWM was obtained for 38 very healthy elderly adult men (mean age = 66.3 years; SD = 6.0; range = 55-76). To evaluate regional specificity, we also assessed a contrasting early-myelinating region (splenium of the corpus callosum; SWM), which primarily contains axons involved in visual processing. CPS was assessed using the Trail Making Test. Results: LMWM R[subscript 2] and CPS measures were significantly correlated (r = 0.515, p = 0.0009), but no significant association between R[subscript 2] and CPS was detected in the splenium (p = 0.409). LMWM R[subscript 2], but not SWM R[subscript 2], was a significant mediator of the relationship between age and CPS (p = 0.037). Conclusions: In this very healthy elderly sample, age-related slowing in CPS is mediated by myelin breakdown in highly vulnerable late-myelinating regions but not in the splenium. (Contains 1 table and 5 figures.)
Elsevier. 6277 Sea Harbor Drive, Orlando, FL 32887-4800. Tel: 877-839-7126; Tel: 407-345-4020; Fax: 407-363-1354; e-mail: usjcs@elsevier.com; Web site: http://www.elsevier.com
Publication Type: Journal Articles; Reports - Research
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A