Neuropathic pain is a type of chronic pain that entails severe prolonged sensory dysfunctions caused by a lesion of the somatosensory system. Many of those suffering from the condition do not experience significant improvement with existing medications, resulting in various side effects. In this study, Sprague-Dawley male rats were used, and long-term deep brain stimulation of the ventrolateral periaqueductal gray was conducted in a rat model of spared nerve injury. We found that 5-Hz deep brain stimulation effectively modulated mechanical allodynia and induced neuronal activation in the rostral ventromedial medulla, restoring impaired descending serotonergic system. At the spinal level, glial cells were still activated but only the 5-HT1a receptor in the spinal cord was activated, implying its inhibitory role in mechanical allodynia. This study found that peripheral neuropathy caused dysfunction in the descending serotonergic system, and prolonged stimulation of ventrolateral periaqueductal gray can modulate the pathway in an efficient manner. This work would provide new opportunities for the development of targeted and effective treatments for this debilitating disease, possibly giving us lower chances of side effects from repeated high-frequency stimulation or long-term use of medication.

中文翻译：

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腹外侧导水管周围灰质的低频 (5-Hz) 刺激可调节周围神经病理性疼痛中的下降血清素能系统。

神经性疼痛是一种慢性疼痛，会因体感系统损伤而导致严重的长期感觉功能障碍。许多患有这种疾病的人在使用现有药物后并没有得到显着改善，从而导致了各种副作用。本研究使用Sprague-Dawley雄性大鼠，在神经损伤的大鼠模型中对腹外侧导水管周围灰质进行长期深部脑刺激。我们发现 5 Hz 深部脑刺激可有效调节机械性异常性疼痛，并诱导延髓头端腹内侧神经元激活，恢复受损的下行血清素能系统。在脊髓水平，神经胶质细胞仍然被激活，但只有脊髓中的 5-HT1a 受体被激活，这表明它在机械性异常性疼痛中具有抑制作用。这项研究发现，周围神经病变导致血清素下降系统功能障碍，长时间刺激腹外侧导水管周围灰质可以有效地调节该通路。这项工作将为开发针对这种使人衰弱的疾病的有针对性和有效的治疗方法提供新的机会，可能会降低我们因重复高频刺激或长期使用药物而产生副作用的机会。