Ravel Sabrina, Sardo Pierangelo, Legallet Eric, Apicella Paul
Laboratoire de Neurobiologie de la Cognition, CNRS, Centre Saint-Charles, 3 place Victor Hugo, 13331 Marseille cedex 3, France.
J Neurophysiol. 2006 May;95(5):2975-86. doi: 10.1152/jn.01113.2005. Epub 2006 Feb 8.
Previous studies have demonstrated that tonically active neurons (TANs) in the primate striatum play an important role in the detection of rewarding events. However, the influence of the spatial features of stimuli or actions required to obtain reward remains unclear. Here, we examined the activity of TANs in the striatum of monkeys trained to make spatially directed movements elicited by visual stimuli presented ipsilaterally or contralaterally to the moving arm. Among 181 neurons responding to the trigger stimulus, 127 (70%) were nonselective for stimulus location and 54 (30%) responded to only one location of the stimulus. Most of the selective responses (63%) occurred when the stimulus was presented contralaterally to the moving arm. To examine whether TAN responses are related to the location of the stimulus or to the direction of the movement, we tested a subset of the trigger-responsive neurons (n = 44) in a condition that elicited reaching toward or away from the stimulus. By comparing TAN activity between the two conditions, we found that half of the responses can be interpreted as being related to the location of the stimulus, one quarter to the direction of movement, and one quarter to the context in which stimulus-movement combination occurs. These results demonstrate that TANs are not limited to motivational processing, but may play a role in the processing of spatial attributes of stimulus and/or movement as well. These response properties suggest that TANs are involved in the flexible shifting of motor responses during spatially directed behavior.
先前的研究表明，灵长类动物纹状体中的紧张性活动神经元（TANs）在奖励事件的检测中发挥着重要作用。然而，获得奖励所需刺激或动作的空间特征的影响仍不清楚。在这里，我们研究了训练猴子在由向移动手臂同侧或对侧呈现的视觉刺激引发的空间定向运动中，纹状体中TANs的活动。在对触发刺激有反应的181个神经元中，127个（70%）对刺激位置无选择性，54个（30%）仅对刺激的一个位置有反应。大多数选择性反应（63%）发生在刺激向移动手臂对侧呈现时。为了研究TANs的反应是与刺激的位置还是与运动的方向相关，我们在一种引发朝向或远离刺激的伸手动作的条件下，测试了一部分对触发有反应的神经元（n = 44）。通过比较这两种条件下TANs的活动，我们发现一半反应可解释为与刺激位置相关，四分之一与运动方向相关，四分之一与刺激 - 运动组合发生的背景相关。这些结果表明，TANs不仅限于动机处理，还可能在刺激和/或运动的空间属性处理中发挥作用。这些反应特性表明，TANs参与了空间定向行为期间运动反应的灵活转换。
