人們常常用“半睡半醒”形容犯困時(shí)做事準(zhǔn)確度下降的情況,。而一項(xiàng)最新研究顯示，實(shí)驗(yàn)鼠的大腦的確可以出現(xiàn)這種狀態(tài),，當(dāng)大腦總體上還處于清醒狀態(tài)時(shí),，某些局部區(qū)域腦電波的測量結(jié)果卻表現(xiàn)出睡眠的特征。
新一期英國《自然》雜志刊登研究報(bào)告說,，美國威斯康星大學(xué)麥迪遜分校等機(jī)構(gòu)研究人員讓一些實(shí)驗(yàn)鼠較長時(shí)期處于清醒狀態(tài),，直到可能開始犯困的時(shí)候。這時(shí)雖然可以明顯看到它們?nèi)栽诨顒?dòng),，其腦電波在總體上也表現(xiàn)出清醒的特征,，但用探針在其大腦中某些局部區(qū)域測量到的腦電波特征卻顯示其已睡著了。
研究人員托諾尼說,，多次實(shí)驗(yàn)顯示,，這些睡眠區(qū)域出現(xiàn)的位置是隨機(jī)的。他比喻說,，這就像燒開水一樣,，在水快要沸騰的時(shí)候，就會有氣泡隨機(jī)地從各處冒出來,，在實(shí)驗(yàn)鼠仍總體清醒但已犯困的時(shí)候,，其大腦中一些區(qū)域開始隨機(jī)地局部入睡。
這些局部入睡的大腦區(qū)域可能與活動(dòng)能力有關(guān),，這較好地解釋了在“半睡半醒”狀態(tài)下做事準(zhǔn)確度下降的情況,。本次研究也顯示，那些半睡半醒中的實(shí)驗(yàn)鼠,，用爪子獲取食物的準(zhǔn)確度明顯下降,。
一些專家認(rèn)為，這項(xiàng)研究結(jié)果提醒人們應(yīng)該重新思考什么是睡眠,，睡著和清醒可能不像通常認(rèn)為的那樣是兩個(gè)截然分開的狀態(tài),。既然醒著的時(shí)候可能有部分大腦區(qū)域入睡，那么睡著的時(shí)候也可能會有一些大腦區(qū)域處于清醒狀態(tài),，對此深入研究或有助于解釋夢游等現(xiàn)象,。（生物谷Bioon.com）
生物谷推薦原文出處：
Nature DOI： doi:10.1038/nature10009
Local sleep in awake rats
Vladyslav V. Vyazovskiy; Umberto Olcese; Erin C. Hanlon; Yuval Nir; Chiara Cirelli; Giulio Tononi
In an awake state, neurons in the cerebral cortex fire irregularly and electroencephalogram (EEG) recordings display low-amplitude, high-frequency fluctuations. During sleep, neurons oscillate between ‘on’ periods, when they fire as in an awake brain, and ‘off’ periods, when they stop firing altogether and the EEG displays high-amplitude slow waves. However, what happens to neuronal firing after a long period of being awake is not known. Here we show that in freely behaving rats after a long period in an awake state, cortical neurons can go briefly ‘offline’ as in sleep, accompanied by slow waves in the local EEG. Neurons often go offline in one cortical area but not in another, and during these periods of ‘local sleep’, the incidence of which increases with the duration of the awake state, rats are active and display an ‘awake’ EEG. However, they are progressively impaired in a sugar pellet reaching task. Thus, although both the EEG and behaviour indicate wakefulness, local populations of neurons in the cortex may be falling asleep, with negative consequences for performance.
