Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON, Canada.
Department of Comparative Biology and Experimental Medicine, University of Calgary, Calgary, AB, Canada.
Front Neural Circuits. 2020 Jun 12;14:31. doi: 10.3389/fncir.2020.00031. eCollection 2020.
Somatosensation encompasses a variety of essential modalities including touch, pressure, proprioception, temperature, pain, and itch. These peripheral sensations are crucial for all types of behaviors, ranging from social interaction to danger avoidance. Somatosensory information is transmitted from primary afferent fibers in the periphery into the central nervous system the dorsal horn of the spinal cord. The dorsal horn functions as an intermediary processing center for this information, comprising a complex network of excitatory and inhibitory interneurons as well as projection neurons that transmit the processed somatosensory information from the spinal cord to the brain. It is now known that there can be dysfunction within this spinal cord circuitry in pathological pain conditions and that these perturbations contribute to the development and maintenance of pathological pain. However, the complex and heterogeneous network of the spinal dorsal horn has hampered efforts to further elucidate its role in somatosensory processing. Emerging optical techniques promise to illuminate the underlying organization and function of the dorsal horn and provide insights into the role of spinal cord sensory processing in shaping the behavioral response to somatosensory input that we ultimately observe. This review article will focus on recent advances in optogenetics and fluorescence imaging techniques in the spinal cord, encompassing findings from both and preparations. We will also discuss the current limitations and difficulties of employing these techniques to interrogate the spinal cord and current practices and approaches to overcome these challenges.
躯体感觉包括多种基本感觉模式，包括触觉、压力、本体感觉、温度、疼痛和瘙痒。这些外周感觉对于各种行为都至关重要，从社交互动到避免危险。躯体感觉信息从外周的初级传入纤维传递到中枢神经系统——脊髓的背角。背角作为该信息的中间处理中心，由兴奋性和抑制性中间神经元以及投射神经元组成，这些神经元将处理后的躯体感觉信息从脊髓传递到大脑。现在已知，在病理性疼痛情况下，脊髓回路可能出现功能障碍，这些干扰会导致病理性疼痛的发展和维持。然而，脊髓背角复杂而多样的网络结构阻碍了进一步阐明其在躯体感觉处理中的作用的努力。新兴的光学技术有望阐明背角的基本组织和功能，并深入了解脊髓感觉处理在塑造我们最终观察到的躯体感觉输入行为反应中的作用。本文综述了脊髓中光遗传学和荧光成像技术的最新进展，涵盖了 和 制剂的研究结果。我们还将讨论当前使用这些技术研究脊髓的局限性和困难，以及目前克服这些挑战的实践和方法。
