Neuropathic pain is a chronic pain caused by central and peripheral nerve injury, long-term diabetes or treatment with chemotherapy drugs, and it is dissimilar to other chronic pain conditions. Chronic pain usually seriously affects the quality of life, and its drug treatment may result in increased costs of social and medical care. As in the USA and Canada, in Europe, the demand for pain-relieving medicines used in chronic pain has also significantly increased, but most European countries are not experiencing an opioid crisis. In this review, the role of various endogenous transmitters (noradrenaline, dopamine, serotonin, met- and leu-enkephalins, β-endorphin, dynorphins, cannabinoids, ATP) and various receptors (α2, μ, etc.) in the innate pain-relieving system will be discussed. Furthermore, the modulation of pain processing pathways by transmitters, focusing on neuropathic pain and the role of the sympathetic nervous system in the side effects of excessive opioid treatment, will be explained.

中文翻译：

---

与神经性疼痛相关的内源性神经递质的作用以及在阿片类药物危机中的作用：先天性疼痛缓解系统。

神经性疼痛是由中枢神经和周围神经损伤，长期糖尿病或化疗药物引起的慢性疼痛，与其他慢性疼痛状况不同。慢性疼痛通常会严重影响生活质量，其药物治疗可能会导致社会和医疗费用的增加。与美国和加拿大一样，在欧洲，对用于慢性疼痛的止痛药的需求也显着增加，但是大多数欧洲国家并未遇到阿片类药物危机。在这篇综述中，先天性疼痛中各种内源性递质（去甲肾上腺素，多巴胺，5-羟色胺，甲和亮氨酸脑啡肽，β-内啡肽，强啡肽，大麻素，ATP）和各种受体（α2，μ等）的作用将讨论缓解系统。此外，