Premotor Ramping of Thalamic Neuronal Activity Is Modulated by Nigral Inputs and Contributes to Control the Timing of Action Release
Premotor Ramping of Thalamic Neuronal Activity Is Modulated by Nigral Inputs and Contributes to Control the Timing of Action Release
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DOI：
10.1523/jneurosci.1204-20.2020
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发表时间：
2021-03-03
影响因子：
5.3
通讯作者：
Jaeger, Dieter
中科院分区：
文献类型：
--
作者：
Catanese, Julien;Jaeger, Dieter
腹内侧(Vm)/腹前外侧(Val)运动丘脑是维持正常和病理性运动控制功能和决策的大脑回路中的关键连接。在丘脑的这一区域，一方面，抑制性黑质-丘脑通路提供了来自基底节的主要输出，另一方面，运动丘脑-皮质环参与了目标定向运动之前斜坡准备活动的维持。为了更好地了解黑质对丘脑活动的影响，我们记录了雄性和雌性小鼠在执行延迟的右/左决策舔食任务时，Vm/Val神经元的电生理反应。对正确试验(CORR)和错误试验的分析表明，与正确试验相比，过早舔舔(冲动行为)的丘脑斜坡活动更强，而没有舔舔的试验[遗漏(OMI)]的丘脑斜坡活动更弱。在任务的延迟期，通过光基因激活运动丘脑的黑质终末来抑制斜坡活动，会降低冲动动作的可能性，增加遗漏试验的数量。我们提出了一个简约的模型来解释我们的数据，并得出结论，丘脑的倾斜机制有助于控制适当的动作释放时间，而抑制性黑质输入足以中断这一机制，并在这项任务中调节运动冲动量。
The ventromedial (VM)/ventro-anterior-lateral (VAL) motor thalamus is a key junction within the brain circuits sustaining normal and pathologic motor control functions and decision-making. In this area of thalamus, on one hand, the inhibitory nigro-thalamic pathway provides a main output from the basal ganglia, and, on the other hand, motor thalamo-cortical loops are involved in the maintenance of ramping preparatory activity before goal-directed movements. To better understand the nigral impact on thalamic activity, we recorded electrophysiological responses from VM/VAL neurons while male and female mice were performing a delayed right/left decision licking task. Analysis of correct (corr) and error trials revealed that thalamic ramping activity was stronger for premature licks (impulsive action) and weaker for trials with no licks [omission (omi)] compared with correct trials. Suppressing ramping activity through optogenetic activation of nigral terminals in the motor thalamus during the delay epoch of the task led to a reduced probability of impulsive action and an increased amount of omissions trials. We propose a parsimonious model explaining our data and conclude that a thalamic ramping mechanism contributes to the control of proper timing of action release and that inhibitory nigral inputs are sufficient to interrupt this mechanism and modulate the amount of motor impulsivity in this task.