Spatial representations in the superior colliculus are modulated by competition among targets
Spatial representations in the superior colliculus are modulated by competition among targets
复制标题
DOI：
10.1016/j.neuroscience.2019.04.002
复制
发表时间：
2019-06-01
期刊：
影响因子：
3.3
通讯作者：
Felsen, Gidon
中科院分区：
文献类型：
--
作者：
Lintz, Mario J.;Essig, Jaclyn;Felsen, Gidon
选择和移动空间目标是目标导向行为的关键组成部分，但其神经基础还没有被很好地理解。上丘(SC)被认为包含对侧空间的地形图，在该地形图中特定神经元群体的活动对应于特定的空间位置。然而，这些空间表达受到几个与决策相关的变量的影响，这表明它们反映的信息不仅仅是即将到来的运动的位置。在这里，我们考察这些表现形式在多大程度上源于竞争性的空间选择。我们记录了在两种情况下执行行为任务的雄性小鼠的SC活动，该任务要求将运动定向到水奖励的目标上。在“竞争性”试验中，左目标或右目标都可以得到奖励，这取决于在中央端口提供的刺激方案。在“非竞争性”试验中，相同的目标(例如，左侧)在整个区块中得到奖励。虽然两种试验类型都需要将运动定向到相同的空间目标，但只有在竞争性试验中，目标才会竞争选择。我们发现，在竞争性试验中，运动前的SC活动预测了运动到对侧目标的运动，正如预期的那样。然而，在非竞争性试验中，一些神经元失去了空间选择性，而在另一些神经元中，活动预测了向同侧目标的移动。与这些发现一致的是，运动前SC活性的单侧光遗传失活本身偏向于竞争性试验，但不是非竞争性试验。将这些结果结合到SC活动的吸引子模型中，指出了在竞争和非竞争条件下定位运动的不同路径，SC特别需要在多个潜在目标中进行选择。(C)2019 IBRO。爱思唯尔有限公司出版。保留所有权利。
Selecting and moving to spatial targets are critical components of goal-directed behavior, yet their neural bases are not well understood. The superior colliculus (SC) is thought to contain a topographic map of contralateral space in which the activity of specific neuronal populations corresponds to particular spatial locations. However, these spatial representations are modulated by several decision-related variables, suggesting that they reflect information beyond simply the location of an upcoming movement. Here, we examine the extent to which these representations arise from competitive spatial choice. We recorded SC activity in male mice performing a behavioral task requiring orienting movements to targets for a water reward in two contexts. In "competitive" trials, either the left or right target could be rewarded, depending on which stimulus was presented at the central port. In "noncompetitive" trials, the same target (e.g., left) was rewarded throughout an entire block. While both trial types required orienting movements to the same spatial targets, only in competitive trials do targets compete for selection. We found that in competitive trials, pre-movement SC activity predicted movement to contralateral targets, as expected. However, in noncompetitive trials, some neurons lost their spatial selectivity and in others activity predicted movement to ipsilateral targets. Consistent with these findings, unilateral optogenetic inactivation of pre-movement SC activity ipsiversively biased competitive, but not noncompetitive, trials. Incorporating these results into an attractor model of SC activity points to distinct pathways for orienting movements under competitive and noncompetitive conditions, with the SC specifically required for selecting among multiple potential targets. (C) 2019 IBRO. Published by Elsevier Ltd. All rights reserved.