کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
328863 1433666 2006 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Age and cholinergic effects on hemodynamics and functional coherence of human hippocampus
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی سالمندی
پیش نمایش صفحه اول مقاله
Age and cholinergic effects on hemodynamics and functional coherence of human hippocampus
چکیده انگلیسی

Aging is normally associated with increased predictability of neurophysiological processes. To test the related prediction of age-related increase in the Hurst exponent, H, of functional MRI time series, and its possible cholinergic mechanisms, two groups of healthy participants (old [mean age = 65 years]; young [mean age = 22 years]; N = 11 per group) were scanned twice at rest, following placebo and a muscarinic receptor antagonist, scopolamine 0.3 mg. Older age was associated with significant increase in H of fMRI time series in bilateral hippocampus. Similarly, scopolamine was associated with increased H in left hippocampus; and there was an age-by-drug interaction in medial temporal lobe whereby older participants specifically had increased H following scopolamine. Scopolamine also enhanced fronto-hippocampal low-frequency coherence, and this could be correlated with its effect on hippocampal H. Thus, increased persistence of hippocampal dynamics in older subjects is demonstrable by resting fMRI; scopolamine mimics these effects, especially in older subjects, implying a cholinergic mechanism for age-related change; and cholinergic effects on hippocampal dynamics are associated with enhanced functional connectivity between frontal cortex and hippocampus.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Neurobiology of Aging - Volume 27, Issue 10, October 2006, Pages 1395–1404
نویسندگان
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