MRC Laboratory of Molecular Biology, Cambridge, UK.
St Edmund's College, University of Cambridge, Cambridge, UK.
Nature. 2024 Jul;631(8020):378-385. doi: 10.1038/s41586-024-07619-2. Epub 2024 Jul 3.
The execution of goal-oriented behaviours requires a spatially coherent alignment between sensory and motor maps. The current model for sensorimotor transformation in the superior colliculus relies on the topographic mapping of static spatial receptive fields onto movement endpoints. Here, to experimentally assess the validity of this canonical static model of alignment, we dissected the visuo-motor network in the superior colliculus and performed in vivo intracellular and extracellular recordings across layers, in restrained and unrestrained conditions, to assess both the motor and the visual tuning of individual motor and premotor neurons. We found that collicular motor units have poorly defined visual static spatial receptive fields and respond instead to kinetic visual features, revealing the existence of a direct alignment in vectorial space between sensory and movement vectors, rather than between spatial receptive fields and movement endpoints as canonically hypothesized. We show that a neural network built according to these kinetic alignment principles is ideally placed to sustain ethological behaviours such as the rapid interception of moving and static targets. These findings reveal a novel dimension of the sensorimotor alignment process. By extending the alignment from the static to the kinetic domain this work provides a novel conceptual framework for understanding the nature of sensorimotor convergence and its relevance in guiding goal-directed behaviours.
目标导向行为的执行需要感觉和运动图谱之间在空间上具有一致性。上丘中感觉运动转换的当前模型依赖于静态空间感受野到运动终点的拓扑映射。在这里,为了实验评估这种对齐的典型静态模型的有效性,我们在上丘中解剖了视动网络,并在约束和非约束条件下在各层进行了体内细胞内和细胞外记录,以评估单个运动和前运动神经元的运动和视觉调谐。我们发现,丘脑中的运动单位具有定义不明确的视觉静态空间感受野,而是对运动学视觉特征做出反应,这表明在感觉和运动矢量之间存在矢量空间中的直接对齐,而不是按照经典假设在空间感受野和运动终点之间对齐。我们表明,根据这些运动学对齐原则构建的神经网络非常适合维持诸如快速拦截运动和静态目标等行为。这些发现揭示了感觉运动对准过程的一个新维度。通过将对准从静态扩展到运动学领域,这项工作为理解感觉运动收敛的性质及其在指导目标导向行为中的相关性提供了一个新的概念框架。