Abstract：
Sensory neurons are responsible for the generation and transmission of nociceptive signals from the periphery to the central nervous system. They encompass a broadly heterogeneous population of highly specialized neurons. The understanding of the molecular choreography of individual subpopulations is essential to understand physiological and pathological pain states. Recently, it became evident that species differences limit transferability of research findings between human and rodents in pain research. Thus, it is necessary to systematically compare and categorize the electrophysiological data gained from human and rodent dorsal root ganglia neurons (DRGs). In this systematic review, we condense the available electrophysiological data defining subidentities in human and rat DRGs. A systematic search on PUBMED yielded 30 studies on rat and 3 studies on human sensory neurons. Defined outcome parameters included current clamp, voltage clamp, cell morphology, pharmacological readouts, and immune reactivity parameters. We compare evidence gathered for outcome markers to define subgroups, offer electrophysiological parameters for the definition of neuronal subtypes, and give a framework for the transferability of electrophysiological findings between species. A semiquantitative analysis revealed that for rat DRGs, there is an overarching consensus between studies that C-fiber linked sensory neurons display a lower action potential threshold, higher input resistance, a larger action potential overshoot, and a longer afterhyperpolarization duration compared to other sensory neurons. They are also more likely to display an infliction point in the falling phase of the action potential. This systematic review points out the need of more electrophysiological studies on human sensory neurons.
摘要：
感觉神经元负责伤害性信号从外周到中枢神经系统的产生和传递。它们包括高度特化的神经元的广泛异质群体。了解个体亚群的分子编舞对于了解生理和病理性疼痛状态至关重要。最近,很明显，在疼痛研究中，物种差异限制了研究结果在人类和啮齿动物之间的可转移性。因此，有必要系统地比较和分类从人类和啮齿动物背根神经节神经元（DRGs）获得的电生理数据。在这次系统审查中，我们浓缩了定义人类和大鼠DRG亚身份的可用电生理数据。对PUBMED的系统搜索产生了30项关于大鼠的研究和3项关于人类感觉神经元的研究。定义的结果参数包括电流钳，电压钳,细胞形态学,药理学读数，和免疫反应性参数。我们比较收集的结果标记的证据来定义亚组，为神经元亚型的定义提供电生理参数，并为物种之间的电生理发现的可转移性提供了框架。半定量分析表明，对于大鼠DRGs，在C纤维连接的感觉神经元显示较低的动作电位阈值的研究之间有一个总体共识，较高的输入电阻，更大的动作电位过冲，与其他感觉神经元相比，超极化后持续时间更长。他们也更有可能在动作电位的下降阶段显示出加点。本系统综述指出需要对人类感觉神经元进行更多的电生理研究。
