Champalimaud Neuroscience Programme, Champalimaud Center for the Unknown, Lisbon, Portugal.
Program in Neuroscience, Department of Neurobiology, Harvard University, Boston, Massachusetts, USA.
Nat Neurosci. 2017 Jan;20(1):72-81. doi: 10.1038/nn.4435. Epub 2016 Oct 31.
The integration of sensorimotor signals to internally estimate self-movement is critical for spatial perception and motor control. However, which neural circuits accurately track body motion and how these circuits control movement remain unknown. We found that a population of Drosophila neurons that were sensitive to visual flow patterns typically generated during locomotion, the horizontal system (HS) cells, encoded unambiguous quantitative information about the fly's walking behavior independently of vision. Angular and translational velocity signals were integrated with a behavioral-state signal and generated direction-selective and speed-sensitive graded changes in the membrane potential of these non-spiking cells. The nonvisual direction selectivity of HS cells cooperated with their visual selectivity only when the visual input matched that expected from the fly's movements, thereby revealing a circuit for internally monitoring voluntary walking. Furthermore, given that HS cells promoted leg-based turning, the activity of these cells could be used to control forward walking.
感觉运动信号的整合对于内部自我运动的估计对于空间感知和运动控制至关重要。然而，哪些神经回路能准确地跟踪身体运动，以及这些回路如何控制运动，目前还不清楚。我们发现，一种对通常在运动过程中产生的视觉流模式敏感的果蝇神经元群体，即水平系统 (HS) 细胞，独立于视觉，对苍蝇的行走行为产生了明确的定量信息编码。角和翻译速度信号与行为状态信号相结合，在这些非尖峰细胞的膜电位中产生方向选择性和速度敏感的渐变变化。HS 细胞的非视觉方向选择性只有在视觉输入与苍蝇运动所期望的输入匹配时，才与它们的视觉选择性合作，从而揭示了一个用于内部监测自愿行走的电路。此外，由于 HS 细胞促进了基于腿部的转弯，这些细胞的活动可以用来控制向前行走。
