Zhao Peixiong, Tong Yuxin, Lazarte Ivan P, Khan Biswadeep, Tian Guangnan, Chen Kenny K Y, Lam Thomas K C, Hu Yu, Semmelhack Julie L
Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong Special Administrative Region, China.
Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom.
Proc Natl Acad Sci U S A. 2025 Apr;122(13):e2416215122. doi: 10.1073/pnas.2416215122. Epub 2025 Mar 24.
The visual system can process diverse stimuli and make the decision to execute appropriate behaviors, but it remains unclear where and how this transformation takes place. Innate visually evoked behaviors such as hunting, freezing, and escape are thought to be deeply conserved, and have been described in a range of species from insects to humans. We found that zebrafish larvae would respond to predator-like visual stimuli with immobility and bradycardia, both hallmarks of freezing, in a head-fixed behavioral paradigm. We then imaged the zebrafish visual system while larvae responded to different visual stimuli with hunting, freezing, and escape behaviors and systematically identified visually driven neurons and behaviorally correlated sensorimotor neurons. Our analyses indicate that within the optic tectum, broadly tuned sensory neurons are functionally correlated with sensorimotor neurons which respond specifically during one behavior, indicating that it contains suitable information for sensorimotor transformation. We also identified sensorimotor neurons in four other areas downstream of the tectum, and these neurons are also specific for one behavior, indicating that the segregation of the pathways continues in other areas. While our findings shed light on how sensorimotor neurons may integrate visual inputs, further investigation will be required to determine how sensorimotor neurons in different regions interact and where the decision to behave is made.
视觉系统能够处理各种刺激并做出执行适当行为的决定，但这种转变发生的位置和方式仍不清楚。诸如捕猎、冻结和逃避等先天性视觉诱发行为被认为是高度保守的，并且在从昆虫到人类的一系列物种中都有描述。我们发现，在头部固定的行为范式中，斑马鱼幼体会对类似捕食者的视觉刺激做出静止不动和心动过缓的反应，这两者都是冻结反应的特征。然后，我们在斑马鱼幼体对不同视觉刺激做出捕猎、冻结和逃避行为反应时，对其视觉系统进行成像，并系统地识别出视觉驱动神经元和与行为相关的感觉运动神经元。我们的分析表明，在视顶盖内，广泛调谐的感觉神经元在功能上与在一种行为中特异性反应的感觉运动神经元相关，这表明它包含了用于感觉运动转换的合适信息。我们还在视顶盖下游的其他四个区域识别出了感觉运动神经元，并且这些神经元也对一种行为具有特异性，这表明通路的分离在其他区域也持续存在。虽然我们的发现揭示了感觉运动神经元可能如何整合视觉输入，但仍需要进一步研究来确定不同区域的感觉运动神经元如何相互作用以及行为决定是在哪里做出的。
