Contribution of pedunculopontine tegmental nucleus neurons to performance of visually guided saccade tasks in monkeys
Contribution of pedunculopontine tegmental nucleus neurons to performance of visually guided saccade tasks in monkeys
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DOI：
10.1152/jn.2002.88.2.715
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发表时间：
2002-08-01
影响因子：
2.5
通讯作者：
Aizawa, H
中科院分区：
文献类型：
--
作者：
Kobayashi, Y;Inoue, Y;Aizawa, H
胆碱能桥脚被盖核（PPTN）是脑干中主要的上行唤醒系统之一，与运动系统、边缘系统和感觉系统有关。基于先前的研究，我们假设PPTN可能与行为动物的运动、强化和任务表现的综合控制有关。为了研究PPTN在行为控制中的作用，我们分析了3只猴子在视觉引导下的扫视任务中PPTN神经元的活动与扫视准备、执行、奖励和任务表现的关系。在视觉引导的扫视过程中，我们观察到与扫视相关的爆发神经元（26/70）和暂停神经元（19/70），表明PPTN神经元的一个子集与扫视执行和注视都有关。爆发神经元比暂停神经元对扫视方向表现出更强的选择性。爆发和暂停神经元的首选方向既不与水平轴对齐也不与垂直轴对齐，也不强烈偏向于同侧或对侧方向。PPTN神经元的扫视相关活动的空间表征与其他脑干扫视系统不同，因此可能传递来自不同区域的扫视相关活动。在一些神经元的奖赏开始时观察到放电增加（22/70）。这些神经元在大约140毫秒内对自由传递的奖励做出反应。然而，在快速扫视任务中，奖励开始前后的反应潜伏期在奖励开始前100毫秒和奖励开始后200毫秒之间。这些结果表明，在任务中适当扫视后观察到的活动可能包括与奖励相关的反应。我们发现，当动物在确保任务中趋于失败时，对注视点（FP）出现的反应时间更长。这种对FP外观的反应时间（RTFP）作为动机的指标。RTFP可以通过PPTN神经元子集（13/70）的神经元活动来预测，这些神经元的活动水平随任务表现而变化，在成功和错误的试验中放电率更高。在PPTN神经元中观察到与扫视执行、奖励传递和任务表现相关的反应组合。我们从PPTN神经元的多模态反应中得出结论，PPTN可能是执行目的行为所需的各种信号之间的综合接口。
The cholinergic pedunculopontine tegmental nucleus (PPTN) is one of the major ascending arousal systems in the brain stem and is linked to motor, limbic, and sensory systems. Based on previous studies, we hypothesized that PPTN would be related to the integrative control of movement, reinforcement, and performance of tasks in behaving animals. To investigate how PPTN contributes to the behavioral control, we analyzed the activity of PPTN neurons during visually guided saccade tasks in three monkeys in relation to saccade preparation, execution, reward, and performance of the task. During visually guided saccades, we observed saccade-related burst (26/70) and pause neurons (19/70), indicating that a subset of PPTN neurons are related to both saccade execution and fixation. Burst neurons exhibited greater selectivity for saccade direction than pause neurons. The preferred directions for both burst and pause neurons were not aligned with either horizontal or vertical axes, nor biased strongly in either the ipsilateral or the contralateral direction. The spatial representation of the saccade-related activity of PPTN neurons is different from other brain stem saccade systems and may therefore relay saccade-related activity from different areas. Increasing discharges were observed around reward onset in a subset of neurons (22/70). These neurons responded to the freely delivered rewards within similar to140 ms. However, during the saccade task, the latencies of the responses around reward onset ranged between 100 ms before and 200 ms after the reward onset. These results suggest that the activity observed after appropriate saccade during the task may include response associated with reward. We found that the reaction time to the appearance of the fixation point (FP) was longer when the animal tended to fail in the ensuring task. This reaction time to FP appearance (RTFP) served as an index of motivation. The RTFP could be predicted by the neuronal activity of a subset of PPTN neurons (13/70) that varied their activity levels with task performance, discharging at a higher rate in successful versus error trials. A combination of responses related to saccade execution, reward delivery, and task performance was observed in PPTN neurons. We conclude from the multimodality of responses in PPTN neurons that PPTN may serve as an integrative interface between the various signals required for performing purposive behaviors.