Siuda Edward R, Copits Bryan A, Schmidt Martin J, Baird Madison A, Al-Hasani Ream, Planer William J, Funderburk Samuel C, McCall Jordan G, Gereau Robert W, Bruchas Michael R
Department of Anesthesiology, Basic Research Division, Washington University in St. Louis, St. Louis, MO 63110, USA; Division of Biological and Biomedical Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA.
Department of Anesthesiology, Basic Research Division, Washington University in St. Louis, St. Louis, MO 63110, USA; Washington University Pain Center, Washington University in St. Louis, St. Louis, MO 63110, USA.
Neuron. 2015 May 20;86(4):923-935. doi: 10.1016/j.neuron.2015.03.066. Epub 2015 Apr 30.
Optogenetics is now a widely accepted tool for spatiotemporal manipulation of neuronal activity. However, a majority of optogenetic approaches use binary on/off control schemes. Here, we extend the optogenetic toolset by developing a neuromodulatory approach using a rationale-based design to generate a Gi-coupled, optically sensitive, mu-opioid-like receptor, which we term opto-MOR. We demonstrate that opto-MOR engages canonical mu-opioid signaling through inhibition of adenylyl cyclase, activation of MAPK and G protein-gated inward rectifying potassium (GIRK) channels and internalizes with kinetics similar to that of the mu-opioid receptor. To assess in vivo utility, we expressed a Cre-dependent viral opto-MOR in RMTg/VTA GABAergic neurons, which led to a real-time place preference. In contrast, expression of opto-MOR in GABAergic neurons of the ventral pallidum hedonic cold spot led to real-time place aversion. This tool has generalizable application for spatiotemporal control of opioid signaling and, furthermore, can be used broadly for mimicking endogenous neuronal inhibition pathways.
光遗传学现已成为一种被广泛接受的用于对神经元活动进行时空操纵的工具。然而，大多数光遗传学方法采用的是二进制开/关控制方案。在此，我们通过开发一种基于原理设计的神经调节方法来扩展光遗传学工具集，以生成一种与Gi偶联、对光敏感的μ-阿片样受体，我们将其命名为光遗传学μ-阿片样受体（opto-MOR）。我们证明，opto-MOR通过抑制腺苷酸环化酶、激活丝裂原活化蛋白激酶（MAPK）和G蛋白门控内向整流钾通道（GIRK）来参与经典的μ-阿片样信号传导，并且其内化动力学与μ-阿片样受体相似。为了评估其在体内的效用，我们在中脑导水管周围灰质/腹侧被盖区（RMTg/VTA）的γ-氨基丁酸能（GABAergic）神经元中表达了一种依赖于Cre的病毒opto-MOR，这导致了实时位置偏好。相比之下，在腹侧苍白球享乐冷点的GABAergic神经元中表达opto-MOR则导致了实时位置厌恶。该工具可广泛应用于对阿片样信号传导的时空控制，此外，还可广泛用于模拟内源性神经元抑制途径。
