Terada Yuki, Morita-Takemura Shoko, Isonishi Ayami, Tanaka Tatsuhide, Okuda Hiroshi, Tatsumi Kouko, Shinjo Takeaki, Kawaguchi Masahiko, Wanaka Akio
Department of Anatomy & Neuroscience, Faculty of Medicine, Nara Medical University, 840 Shijo-cho, Kashihara, Nara, 634-8521, Japan; Department of Anesthesiology, Nara Medical University, 840, Shijo-cho Kashihara, Nara 634-8522, Japan.
Department of Anatomy & Neuroscience, Faculty of Medicine, Nara Medical University, 840 Shijo-cho, Kashihara, Nara, 634-8521, Japan.
Neurosci Lett. 2018 Nov 1;686:67-73. doi: 10.1016/j.neulet.2018.08.051. Epub 2018 Sep 3.
Neuropathic pain is initiated by a primary lesion in the peripheral nervous system and spoils quality of life. Neurotrophins play important roles in the development and transmission of neuropathic pain. There are conflicting reports that the dorsal root ganglion (DRG) in an injured nerve contribute to neuropathic pain, whereas several studies have highlighted the important contribution of the DRG in a non-injured nerve. Clarifying the role of neurotrophins in neuropathic pain is problematic because we cannot distinguish injured and intact neurons in most peripheral nerve injury models. In the present study, to elicit neuropathic pain, we used the spared nerve injury (SNI) model, in which injured DRG neurons are distinguishable from intact ones, and mechanical allodynia develops in the intact sural nerve skin territory. We examined nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) expression in the DRGs of SNI model mice. NGF and BDNF levels increased in the injured L3 DRG, while NGF decreased in the intact L5 DRG. These data offer a new point of view on the role of these neurotrophins in neuropathic pain induced by peripheral nerve injury.
神经性疼痛由外周神经系统的原发性损伤引发，会破坏生活质量。神经营养因子在神经性疼痛的发生和传导中发挥着重要作用。有相互矛盾的报道称，受损神经中的背根神经节（DRG）会导致神经性疼痛，而多项研究则强调了DRG在未受损神经中的重要作用。由于在大多数外周神经损伤模型中我们无法区分受损神经元和完整神经元，因此阐明神经营养因子在神经性疼痛中的作用存在问题。在本研究中，为了引发神经性疼痛，我们使用了保留神经损伤（SNI）模型，在该模型中，受损的DRG神经元可与完整神经元区分开来，并且在完整的腓肠神经皮肤区域会出现机械性异常性疼痛。我们检测了SNI模型小鼠DRG中神经生长因子（NGF）和脑源性神经营养因子（BDNF）的表达。受损的L3 DRG中NGF和BDNF水平升高，而完整的L5 DRG中NGF水平降低。这些数据为这些神经营养因子在周围神经损伤诱导的神经性疼痛中的作用提供了新的观点。
