Phasic Activation of Individual Neurons in the Locus Ceruleus/Subceruleus Complex of Monkeys Reflects Rewarded Decisions to Go But Not Stop
Phasic Activation of Individual Neurons in the Locus Ceruleus/Subceruleus Complex of Monkeys Reflects Rewarded Decisions to Go But Not Stop
复制标题
DOI：
10.1523/jneurosci.2566-14.2014
复制
发表时间：
2014-10-08
影响因子：
5.3
通讯作者：
Gold, Joshua I.
中科院分区：
文献类型：
--
作者：
Kalwani, Rishi M.;Joshi, Siddhartha;Gold, Joshua I.
脑干蓝斑核（LC）中的神经元在简单的感觉运动任务中经常表现出阶段性激活。这种激活导致去甲肾上腺素在整个大脑中的释放，其功能作用尚不清楚，部分原因是它发生的条件仍然存在疑问。早期的研究主要集中在LC阶段性激活与显著感觉事件的关系上，而最近的工作则强调其相对于目标导向行为反应的时间，可能代表了感觉运动决策过程的结束。为了更好地了解LC阶段性激活和感觉，运动和决策处理之间的关系，我们记录了尖峰活动的神经元在LC+（LC和相邻的，含有去甲肾上腺素的蓝斑下核）的猴子执行一个countermanding任务。这项任务要求猴子偶尔停止有计划的、扫视视觉目标的眼球运动。我们发现，许多隔离良好的LC+单位响应于指示猴子发起扫视的视觉提示的发作，并在扫视发作后再次作出反应，即使在停止信号的存在下错误地发起。这些神经元中的许多对任务背景之外的扫视没有反应。相比之下，无论是停止信号的出现，也没有成功的抑制眼跳引起LC+反应。因此，LC+阶段性激活编码与决定执行有关的感觉和运动事件，但不保留运动，这意味着目标导向的行动中的功能作用，但不一定是更隐蔽的处理形式。
Neurons in the brainstem nucleus locus ceruleus (LC) often exhibit phasic activation in the context of simple sensory-motor tasks. The functional role of this activation, which leads to the release of norepinephrine throughout the brain, is not yet understood in part because the conditions under which it occurs remain in question. Early studies focused on the relationship of LC phasic activation to salient sensory events, whereas more recent work has emphasized its timing relative to goal-directed behavioral responses, possibly representing the end of a sensory-motor decision process. To better understand the relationship between LC phasic activation and sensory, motor, and decision processing, we recorded spiking activity of neurons in the LC+ (LC and the adjacent, norepinephrine-containing subceruleus nucleus) of monkeys performing a countermanding task. The task required the monkeys to occasionally withhold planned, saccadic eye movements to a visual target. We found that many well isolated LC+ units responded to both the onset of the visual cue instructing the monkey to initiate the saccade and again after saccade onset, even when it was initiated erroneously in the presence of a stop signal. Many of these neurons did not respond to saccades made outside of the task context. In contrast, neither the appearance of the stop signal nor the successful withholding of the saccade elicited an LC+ response. Therefore, LC+ phasic activation encodes sensory and motor events related to decisions to execute, but not withhold, movements, implying a functional role in goal-directed actions, but not necessarily more covert forms of processing.