Martinez Erik, Lin Harvey H, Zhou Haocheng, Dale Jahrane, Liu Kevin, Wang Jing
Department of Anesthesiology, Perioperative Care and Pain Medicine, New York University School of MedicineNew York, NY, United States.
Department of Neuroscience and Physiology, New York University School of MedicineNew York, NY, United States.
Front Cell Neurosci. 2017 May 26;11:146. doi: 10.3389/fncel.2017.00146. eCollection 2017.
The mechanisms for acute pain regulation in the brain are not well understood. The prefrontal cortex (PFC) provides top-down control of emotional processes, and it projects to the nucleus accumbens (NAc). This corticostriatal projection forms an important regulatory pathway within the brain's reward system. Recently, this projection has been suggested to control both sensory and affective phenotypes specifically associated with chronic pain. As this projection is also known to play a role in the transition from acute to chronic pain, we hypothesized that this corticostriatal circuit can also exert a modulatory function in the acute pain state. Here, we used optogenetics to specifically target the projection from the PFC to the NAc. We tested sensory pain behaviors with Hargreaves' test and mechanical allodynia, and aversive pain behaviors with conditioned place preference (CPP) test. We found that the activation of this corticostriatal circuit gave rise to bilateral relief from peripheral nociceptive inputs. Activation of this circuit also provided important control for the aversive response to transient noxious stimulations. Hence, our results support a novel role for corticostriatal circuitry in acute pain regulation.
大脑中急性疼痛调节的机制尚未完全清楚。前额叶皮质（PFC）对情绪过程进行自上而下的控制，并投射到伏隔核（NAc）。这种皮质纹状体投射在大脑奖励系统中形成了一条重要的调节通路。最近，有人提出这种投射可特异性控制与慢性疼痛相关的感觉和情感表型。由于已知这种投射在从急性疼痛向慢性疼痛的转变中也起作用，我们推测这种皮质纹状体回路在急性疼痛状态下也能发挥调节功能。在此，我们使用光遗传学技术特异性地靶向从PFC到NAc的投射。我们用哈格里夫斯试验和机械性异常性疼痛测试感觉性疼痛行为，并用条件性位置偏爱（CPP）试验测试厌恶性疼痛行为。我们发现激活这种皮质纹状体回路可使双侧外周伤害性输入得到缓解。激活该回路还为对短暂有害刺激的厌恶反应提供了重要控制。因此，我们的结果支持皮质纹状体回路在急性疼痛调节中的新作用。
