Departments of Bioengineering, University of Colorado - Anschutz Medical Campus, Aurora, CO, USA.
Biomechatronics Development Laboratory, University of Colorado - Anschutz Medical Campus, Aurora, CO, USA.
Sci Rep. 2021 Feb 11;11(1):3664. doi: 10.1038/s41598-021-83280-3.
Vagus nerve stimulation has shown many benefits for disease therapies but current approaches involve imprecise electrical stimulation that gives rise to off-target effects, while the functionally relevant pathways remain poorly understood. One method to overcome these limitations is the use of optogenetic techniques, which facilitate targeted neural communication with light-sensitive actuators (opsins) and can be targeted to organs of interest based on the location of viral delivery. Here, we tested whether retrograde adeno-associated virus (rAAV2-retro) injected in the heart can be used to selectively express opsins in vagus nerve fibers controlling cardiac function. Furthermore, we investigated whether perturbations in cardiac function could be achieved with photostimulation at the cervical vagus nerve. Viral injection in the heart resulted in robust, primarily afferent, opsin reporter expression in the vagus nerve, nodose ganglion, and brainstem. Photostimulation using both one-photon stimulation and two-photon holography with a GRIN-lens incorporated nerve cuff, was tested on the pilot-cohort of injected mice. Changes in heart rate, surface electrocardiogram, and respiratory responses were observed in response to both one- and two-photon photostimulation. The results demonstrate feasibility of retrograde labeling for organ targeted optical neuromodulation.
迷走神经刺激在疾病治疗中显示出许多益处，但目前的方法涉及不精确的电刺激，会产生非靶向效应，而功能相关的途径仍了解甚少。克服这些限制的一种方法是使用光遗传学技术，该技术通过光敏感的执行器（视蛋白）促进靶向神经通讯，并且可以根据病毒递送的位置针对感兴趣的器官进行靶向。在这里，我们测试了逆行腺相关病毒 (rAAV2-retro) 是否可以注射到心脏中，以选择性地在控制心脏功能的迷走神经纤维中表达视蛋白。此外，我们还研究了是否可以通过对颈部迷走神经进行光刺激来实现心脏功能的干扰。病毒在心脏中的注射导致迷走神经、结状神经节和脑干中出现强大的、主要是传入的视蛋白报告基因表达。使用包含 GRIN 透镜的神经袖带的单光子刺激和双光子全息术对注射小鼠的试点队列进行了光刺激测试。观察到心率、体表心电图和呼吸反应的变化，以响应单光子和双光子光刺激。结果表明，逆行标记对于器官靶向光神经调节是可行的。
