The process of awakening: a PET study of regional brain activity patterns mediating the re-establishment of alertness and consciousness
The process of awakening: a PET study of regional brain activity patterns mediating the re-establishment of alertness and consciousness
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DOI：
10.1093/brain/awf228
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发表时间：
2002-10-01
期刊：
影响因子：
14.5
通讯作者：
Herscovitch, P
中科院分区：
文献类型：
--
作者：
Balkin, TJ;Braun, AR;Herscovitch, P
从睡眠中醒来需要快速重建意识，随后是相对缓慢的（20-30分钟后）重新建立警觉性，这是一种时间上的分离，有助于阐明觉醒过程中每个方面的生理基础。（H2O）-O-15 PET用于评估从第二阶段睡眠醒来时区域脑血流量（rCBF）的变化。脑血流（CBF）在中央区（如脑干和丘脑）重建得最快，这表明这些区域的再激活是有意识意识重建的基础。在随后的15分钟清醒状态中，脑血流的进一步增加主要发生在皮质前部区域，这表明睡眠惯性效应（觉醒后表现和警觉性缺陷）的消散是由这些区域的再激活所影响的。在整个觉醒后时期，区域大脑活动的相关模式随之发生变化[特别是前额叶皮层和中脑网状结构（RF）活动之间的负相关性减弱]，前额叶皮层和腹内侧尾状核（CAUD）活动之间的正相关关系表明，睡眠惯性效应的觉醒后逆转可能不仅仅是由再激活介导的——它还可能涉及大脑活动的功能重组。相反，觉醒后稳定的关联——比如在前扣带皮层（ACC）和大多数其他大脑区域之间发现的关联——可能表明了意识本身的功能连接模式。
Awakening from sleep entails rapid re-establishment of consciousness followed by the relatively slow (20-30 min later) re-establishment of alertness-a temporal dissociation that facilitates specification of the physiological underpinnings of each of these facets of the awakening process. (H2O)-O-15 PET was used to assess changes in regional cerebral blood flow (rCBF) upon awakening from stage 2 sleep. Cerebral blood flow (CBF) was most rapidly re-established in centrencephalic regions (e.g. brainstem and thalamus), suggesting that the reactivation of these regions underlies the reestablishment of conscious awareness. Across the ensuing 15 min of wakefulness, further increases in CBF were evident primarily in anterior cortical regions, suggesting that the dissipation of sleep inertia effects (postawakening performance and alertness deficits) is effected by reactivation of these regions. Concomitant shifts in correlation patterns of regional brain activity across the post-awakening period [in particular, a waning negative correlation between prefrontal cortex and mesencephalic reticular formation (RF) activity, and a waxing positive correlation between prefrontal cortex and ventromedial caudate nucleus (CAUD) activity] suggest that the post-awakening reversal of sleep inertia effects may be mediated by more than mere reactivation-it may also involve the functional reorganization of brain activity. Conversely, stable post-awakening correlations-such as those found between the anterior cingulate cortex (ACC) and most other brain regions-may denote the pattern of functional connectivity that underlies consciousness itself.