Abstract：
The pain matrix, which includes several brain regions that respond to pain sensation, contribute to the development of chronic pain. Thus, it is essential to understand the mechanism of causing chronic pain in the pain matrix such as anterior cingulate (ACC), or primary somatosensory (S1) cortex. Recently, combined experiment with the behavior tests and in vivo calcium imaging using fiber photometry revealed the interaction between the neuronal function in deep brain regions of the pain matrix including ACC and the phenotype of chronic pain. However, it remains unclear whether this combined experiment can identify the interaction between neuronal activity in S1, which receive pain sensation, and pain behaviors such as hyperalgesia or allodynia. In this study, to examine whether the interaction between change of neuronal activity in S1 and hyperalgesia in hind paw before and after causing inflammatory pain was detected from same animal, the combined experiment of in vivo fiber photometry system and von Frey hairs test was applied. This combined experiment detected that amplitude of calcium responses in S1 neurons increased and the mechanical threshold of hind paw decreased from same animals which have an inflammatory pain. Moreover, we found that the values between amplitude of calcium responses and mechanical thresholds were shifted to negative correlation after causing inflammatory pain. Thus, the combined experiment with fiber photometry and the behavior tests has a possibility that can simultaneously consider the interaction between neuronal activity in pain matrix and pain induced behaviors and the effects of analgesics or pain treatments.
摘要：
疼痛矩阵，其中包括几个对疼痛有反应的大脑区域，有助于慢性疼痛的发展。因此，了解在疼痛基质中引起慢性疼痛的机制是至关重要的，例如前扣带（ACC），或初级体感（S1）皮层。最近,结合行为测试和使用纤维光度法进行体内钙成像的实验揭示了包括ACC在内的疼痛基质深部脑区的神经元功能与慢性疼痛表型之间的相互作用。然而,目前还不清楚这个联合实验是否可以识别S1神经元活动之间的相互作用，和痛觉过敏或异常性疼痛等疼痛行为。在这项研究中,为了检查是否从同一动物中检测到引起炎性疼痛前后S1中神经元活性的变化与后爪痛觉过敏之间的相互作用，采用体内纤维测光系统和vonFrey毛发试验的联合实验。该组合实验检测到，患有炎性疼痛的相同动物的S1神经元中钙反应的幅度增加，后爪的机械阈值降低。此外，我们发现,在引起炎性疼痛后,钙反应的幅度与机械阈值之间的值变为负相关.因此，纤维测光和行为测试的联合实验有可能同时考虑疼痛基质中神经元活动与疼痛诱发行为之间的相互作用以及镇痛药或疼痛治疗的作用。
