The use of optogenetics to regulate neuronal activity has revolutionized the study of the neural circuitry underlying a number of complex behaviors in rodents. Advances have been particularly evident in the study of brain circuitry and related behaviors, while advances in the study of spinal circuitry have been less striking because of technical hurdles. We have developed and characterized a wireless and fully implantable optoelectronic device that enables optical manipulation of spinal cord circuitry in mice via a microscale light-emitting diode (µLED) placed in the epidural space (NeuroLux spinal optogenetic device). This protocol describes how to surgically implant the device into the epidural space and then analyze light-induced behavior upon µLED activation. We detail optimized optical parameters for in vivo stimulation and demonstrate typical behavioral effects of optogenetic activation of nociceptive spinal afferents using this device. This fully wireless spinal µLED system provides considerable versatility for behavioral assays compared with optogenetic approaches that require tethering of animals, and superior temporal and spatial resolution when compared with other methods used for circuit manipulation such as chemogenetics. The detailed surgical approach and improved functionality of these spinal optoelectronic devices substantially expand the utility of this approach for the study of spinal circuitry and behaviors related to mechanical and thermal sensation, pruriception and nociception. The surgical implantation procedure takes ~1 h. The time required for the study of behaviors that are modulated by the light-activated circuit is variable and will depend upon the nature of the study.

使用光遗传学来调节神经元活动已经彻底改变了对啮齿动物许多复杂行为背后的神经回路的研究。在大脑回路和相关行为的研究中取得的进展尤为明显，而由于技术障碍，脊髓回路研究的进展并不那么引人注目。我们开发并表征了一种无线和完全植入式光电设备，该设备能够通过放置在硬膜外腔（NeuroLux 脊柱光遗传学设备）中的微型发光二极管 (µLED) 对小鼠的脊髓电路进行光学操作。该协议描述了如何通过手术将设备植入硬膜外空间，然后在 µLED 激活时分析光诱导行为。我们详细介绍了用于体内刺激的优化光学参数，并展示了使用该设备对伤害性脊髓传入神经进行光遗传学激活的典型行为效应。与需要束缚动物的光遗传学方法相比，这种完全无线的脊髓 µLED 系统为行为分析提供了相当多的通用性，与用于电路操作的其他方法（如化学遗传学）相比，还具有出色的时间和空间分辨率。这些脊柱光电设备的详细手术方法和改进的功能大大扩展了这种方法的实用性，用于研究与机械和热感觉、瘙痒和伤害感受相关的脊柱电路和行为。手术植入过程需要约 1 小时。