Contextual modulation of central thalamic delay-period activity: representation of visual and saccadic goals.
Contextual modulation of central thalamic delay-period activity: representation of visual and saccadic goals.
复制标题
中央丘脑延迟期活动的情境调节：视觉和扫视目标的表示。
DOI：
10.1152/jn.01221.2003
复制
发表时间：
2004
影响因子：
2.5
通讯作者：
Stanford,TerrenceR
中科院分区：
文献类型：
--
作者：
Wyder,MelanieT;Massoglia,DinoP;Stanford,TerrenceR
本研究探讨了行为环境对灵长类动物中央丘脑视神经元活动的影响。联合收割机结合感官刺激信息和它们的行为相关性的神经元被认为有助于将特定刺激与特定反应联系起来的决策机制。我们在以前的研究中报道，在视觉引导的延迟眼跳任务的整个指示延迟期，中央丘脑的神经元携带空间信息。本研究的目的是确定丘脑神经元的延迟期活动是否受到行为背景的调节。单个神经元进行了评估，在执行视觉引导和记忆引导的变化的眼跳选择任务，其中一个线索指定的反应场刺激作为目标的奖励眼跳或作为一个不相关的干扰。延迟期活动的物理刺激和上下文的相对影响，建议至少有3个神经组。一些神经元发出信号的可见刺激的位置，而不管行为的相关性。其他神经元优先发出当前扫视目标的位置信号，即使在没有物理刺激的情况下也是如此。第三组只给出了当前最佳进球的位置。对于后2组，活动是刺激和上下文的产物，这表明中央丘脑神经元在感觉信号和扫视命令的上下文依赖性联系中发挥作用。更一般地说，这些数据表明，感觉运动决策的解剖学基础可能包括皮质-皮质下回路，中央丘脑作为倒数第二个突触。
This study examines the influence of behavioral context on the activity of visuomotor neurons in primate central thalamus. Neurons that combine information about sensory stimuli and their behavioral relevance are thought to contribute to the decision mechanisms that link specific stimuli to specific responses. We reported in a previous study that neurons in central thalamus carry spatial information throughout the instructed delay period of a visually guided delayed saccade task. The goal of the current study was to determine whether the delay-period activity of thalamic neurons is modulated by behavioral context. Single neurons were evaluated during performance of visually guided and memory-guided variants of a saccadic choice task in which a cue designated the response field stimulus as the target of a rewarded saccade or as an irrelevant distracter. The relative influence of the physical stimulus and context on delay-period activity suggested a minimum of 3 neural groups. Some neurons signaled the locations of visible stimuli regardless of behavioral relevance. Other neurons preferentially signaled the locations of current saccadic goals and did so even in the absence of the physical stimulus. A third group signaled only the locations of currentlyvisiblesaccadic goals. For the latter 2 groups, activity was the product of both stimulus and context, suggesting that central thalamic neurons play a role in the context-dependent linkage of sensory signals and saccadic commands. More generally, these data suggest that the anatomical substrate of sensorimotor decision making may include the cortico-subcortical loops for which central thalamus serves as the penultimate synapse.