Age and cholinergic effects on hemodynamics and functional coherence of human hippocampus
Age and cholinergic effects on hemodynamics and functional coherence of human hippocampus
复制标题
DOI：
10.1016/j.neurobiolaging.2005.08.011
复制
发表时间：
2006-10-01
影响因子：
4.2
通讯作者：
Suckling, John
中科院分区：
文献类型：
--
作者：
Wink, Alle Meije;Bernard, Frederic;Suckling, John
衰老通常与神经生理过程的可预测性增加有关。为了检验功能MRI时间序列中Hurst指数H与年龄相关增加的相关预测及其可能的胆碱能机制，两组健康参与者（老年[平均年龄= 65岁]；年轻[平均年龄= 22岁]；每组N = 11人）在休息时接受两次扫描，分别服用安慰剂和毒碱受体拮抗剂东莨菪碱0.3 mg。年龄越大，双侧海马fMRI时间序列H值显著升高。同样，东莨菪碱与左海马H升高有关；并且在内侧颞叶中存在年龄与药物的相互作用，即老年参与者在服用东莨菪碱后，H值明显增加。东莨菪碱还增强了额海马体的低频一致性，这可能与其对海马h的影响有关。因此，静息fMRI可以证明老年受试者海马动力学的持久性增加；东莨菪碱模拟这些作用，特别是在老年人中，这意味着胆碱能机制与年龄相关的变化；胆碱能对海马体动力学的影响与额叶皮质和海马体之间功能连接的增强有关。(c) 2005爱思唯尔公司版权所有。
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. (c) 2005 Elsevier Inc. All rights reserved.