The role of the pedunculopontine tegmental nucleus in relation to conditioned motor performance in the cat I.: Context-dependent and reinforcement-related single unit activity
The role of the pedunculopontine tegmental nucleus in relation to conditioned motor performance in the cat I.: Context-dependent and reinforcement-related single unit activity
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DOI：
10.1007/s002210050474
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发表时间：
1998-08-01
影响因子：
2
通讯作者：
Farin, D
中科院分区：
文献类型：
--
作者：
Dormont, JF;Condé, H;Farin, D
记录了三只不受约束的猫的脚桥被盖核（PPTg）神经元的活动，这些猫被操作性地调节以执行杠杆释放运动。在简单的反应时间范式中，运动必须在（点击）刺激后快速启动，或者在由音调提示识别的试验中，在相同刺激后必须延迟。成功的试验会得到食物颗粒的奖励。用微电极总共记录了107个神经元。检测到推测为胆碱能的短棘突神经元（平均持续时间：0.7 ms）和宽棘突神经元（平均持续时间：2 ms）。位于 PPTg 区域的 73 个神经元中，53 个有短尖峰，20 个有宽尖峰。活动的变化最常发生在刺激后或强化过程中。大多数具有短暂尖峰的神经元在刺激和强化相关活动后表现出非常早期的兴奋。这些神经元在刺激之前的平均活动为 23.7 脉冲/秒。刺激后激活的延迟时间为 8.6 +/- 6.9 ms（平均值 +/- SD），范围为 4-35 ms。在刺激后必须延迟运动的试验中，早期激活消失或显着减少，表明它是上下文相关的。一小部分具有短暂尖峰的神经元在刺激后最初活动减少，但潜伏期 >9 毫秒。除一个外，所有具有宽尖峰的神经元都具有与强化相关的活动。其中一半仅表现出与强化相关的活动，另一半也表现出刺激后的早期激活。这些神经元在刺激发生之前的一段时间内的活跃程度大约是具有短暂尖峰的神经元的一半。早期上下文依赖性激活与 PPTg 神经元和底丘脑核的兴奋性投射有关。强化相关活动主要出现在推测为胆碱能的宽棘神经元中，推测与 PPTg 神经元向黑质多巴胺能神经元的胆碱能投射有关。最后，讨论了 PPTg 在持续控制运动性能和强化过程中与基底神经节电路相关的作用。
The activity of the pedunculopontine tegmental nucleus (PPTg) neurons was recorded in three unrestrained cats operantly conditioned to perform a lever-release movement. The movement had to be initiated either rapidly after a (click) stimulus in a simple reaction-time paradigm or had to be delayed after the same stimulus in trials identified by a tone cue. Successful trials were rewarded by a food pellet. A total of 107 neurons were recorded with microelectrodes. Brief spike neurons (mean duration: 0.7 ms) and broad spike neurons (mean duration: 2 ms) presumed to be cholinergic were detected. Of the 73 neurons localized in the PPTg area, 53 had brief spikes and 20 broad spikes. Changes in activity most commonly occurred very early after the stimulus or during the reinforcement process. Most neurons with brief spikes exhibited very early excitation after the stimulus and reinforcement-related activity. These neurons had a mean activity of 23.7 impulses/s in the period preceding the stimulus. The onset of activation after the stimulus had a latency of 8.6 +/- 6.9 ms (mean +/- SD), with a range of 4-35 ms. In trials where the movement had to be delayed after the stimulus, the early activation disappeared or was considerably reduced, showing that it was context-dependent. A small proportion of neurons with brief spikes initially decreased activity after the stimulus, but with a latency >9 ms. All the neurons with broad spikes, except one, had reinforcement-related activity. Half of them showed exclusively reinforcement-related activity, the other half also early activation after the stimulus. These neurons were about half as active in the period preceding the stimulus occurrence than the neurons with brief spikes. The early context-dependent activation is discussed in relation to the excitatory projection of PPTg neurons an the subthalamic nucleus. The reinforcement-related activity, preferentially evidenced in broad spike neurons presumed to be cholinergic, is speculated to be associated with cholinergic projection of PPTg neurons to the dopaminergic neurons of the substantia nigra. Finally, the role of PPTg in the ongoing control of motor performance and reinforcement processes is discussed in relation to the basal ganglia circuitry.