美國(guó)的醫(yī)學(xué)研究發(fā)現(xiàn),，從腦部的運(yùn)作可以說明為什么人的舉止從40歲開始，就隨著年齡的增長(zhǎng)而緩慢下來,。
以加州洛杉磯大學(xué)巴特佐基斯醫(yī)生為首的研究小組在《老年神經(jīng)生物學(xué)》雜志上發(fā)表報(bào)告說,，人們進(jìn)行拋球、轉(zhuǎn)向,、操控駕駛盤等動(dòng)作的速度,，是由腦細(xì)胞發(fā)出的指令傳到肌肉所需時(shí)間的快慢來決定，也就是腦波如何快速傳達(dá)出去,。
新研究發(fā)現(xiàn),，即使是健康的人，只要一過40歲這不惑之年,，腦部就會(huì)開始喪失一些傳達(dá)信息的能力,，喪失的速度非常緩慢。
巴特佐基斯醫(yī)生指出,，這說明了為什么很難找到年過40的世界級(jí)運(yùn)動(dòng)員,。他說，人腦就像互聯(lián)網(wǎng),，腦部的髓磷脂（myelin）有如互聯(lián)網(wǎng)的速度寬帶,，健康的髓磷酯緊密圍繞著神經(jīng)纖維，迅速傳達(dá)腦波,。
試驗(yàn)結(jié)果顯示,，點(diǎn)擊速度和髓磷脂健康的高峰期是39歲，過后隨著年齡的增長(zhǎng)而轉(zhuǎn)弱,。（生物谷Bioon.com）
生物谷推薦原始出處：
Neurobiology of Aging doi:10.1016/j.neurobiolaging.2008.08.015
Lifespan trajectory of myelin integrity and maximum motor speed
George Bartzokis, Po H. Lu, Kathleen Tingus, Mario F. Mendez, Aurore Richard, Douglas G. Peters, Bolanle Oluwadara, Katherine A. Barrall, J. Paul Finn, Pablo Villablanca, Paul M. Thompson, d and Jim Mintzf
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 (R2)) 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, R2 of a contrasting early-myelinating region (splenium of the corpus callosum) was also measured.
Results
FLwm R2 and FTS measures were significantly correlated (r = .45, p < .0001) with no association noted in the early-myelinating region (splenium). Both FLwm R2 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 R2 contribute to an age-related reduction in AP burst frequency, it is possible that other brain functions dependent on AP bursts may also be 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.
