Neuroimaging: Unconscious activity in the monkey brain
Neuroimaging: Unconscious activity in the monkey brain
复制标题
神经影像学：猴脑的无意识活动
DOI：
10.1038/nrn2159
复制
发表时间：
2007
影响因子：
34.7
通讯作者：
L. Welberg
中科院分区：
文献类型：
--
作者：
L. Welberg
对人类的功能性磁共振成像（fMRI）研究表明，即使大脑没有从事任何特定的任务，血氧水平依赖（BOLD）信号（被认为反映了神经活动）也会发生自发波动。这些“静止状态”的波动并不是混乱的，但实际上在解剖学和时间上是一致的。这种静息状态活动的意义尚不清楚，到目前为止只在人类中进行了研究。Raichle和他的同事们现在发现，猕猴的大脑也显示出静息状态下的活动，有趣的是，它甚至在动物无意识的时候也会发生。作者发现了三个独立的网络，显示了麻醉猴子的有组织的活动模式。这些系统还显示清醒人类的自发BOLD信号波动。首先，他们研究了眼神经系统，并在该系统的离散区域发现了空间和时间上的鲁棒活动。以一个领域为起点，他们看到这个网络内其他领域的后续活动以一致的顺序和时间框架进行。有趣的是，在麻醉的猴子中显示自发激活的区域先前已被证明与眼部任务有关，这表明相同的网络在清醒的动物执行任务和麻醉下的动物中活跃。
Functional MRI (fMRI) studies in humans have shown that even when the brain is not engaged in any specific tasks, spontaneous fluctuations occur in the blood-oxygen-level-dependent (BOLD) signal (which is thought to reflect neural activity). These'resting state'fluctuations are not chaotic but are in fact anatomically and temporally consistent. The significance of this resting state activity is unclear, and until now had only been investigated in humans. Raichle and colleagues now show that the macaque monkey brain also shows resting state activity and, intriguingly, that it even occurs when the animals are unconscious.The authors found three separate networks showing organized patterns of activity in anaesthetized monkeys. These systems also display spontaneous BOLD signal fluctuations in awake humans. First, they investigated the oculomotor system and found spatially and temporally robust activity in discreet areas of this system. Taking one area as a starting point, they saw subsequent activity in other areas within this network in a consistent order and timeframe. Interestingly, the areas that showed spontaneous activation in the anaesthetized monkeys had previously been shown to be involved in oculomotor tasks, indicating that the same network is active in awake animals performing a task and in animals under anaesthesia.