Gautron M, Guilbaud G
Brain Res. 1982 Apr 15;237(2):459-71. doi: 10.1016/0006-8993(82)90457-7.
Rats rendered polyarthritic by injection of Mycobacterium butyricum into the tail were used as a model for the study of 'chronic pain'. In such rats unitary responses of ventrobasal thalamic neurons to somatic stimulations were dramatically modified by comparison to those described in normal rats investigated in the same anaesthetic conditions. (1) Only the neurons with receptive fields located on inflamed areas (168/194 in 33 rats) have been considered in this study. 27/168 activated only by brushing displayed the classical properties of lemniscal responses; only 20/168 were activated exclusively by intense cutaneous stimuli and 13/168 already activated by light cutaneous stimuli had enhanced discharges when the stimulus intensity was increased. By contrast numerous units (108/168) were excited by mild stimulations applied to the joints or to adjacent cutaneous areas (82 were driven by joint movement and/or mild lateral pressure on the articulation, 26 by brushing the overlapping skin); these responses presented atypical characteristics and displayed unusual patterns with very long afterdischarges of duration several times that of the stimulus. (2) In 20 additional arthritic rats, responses to transcutaneous electrical stimulation (TES) and/or to noxious heat, were obtained for 34 neurones responding to joint stimuli. (a) 16 of 18 neurones tested with transcutaneous electrical stimulation had latencies of 25-100 ms, and thresholds of 1-4 mA (width of shock 2 ms). (b) Neurones activated by joint stimuli frequently responded to noxious heat (radiant or waterbath). Initially, their response thresholds tested in 16 neurones were higher by about 4 degrees C than those of 'noxious' VB neurones in normal rats; however, following sensitization to heat, thresholds were decreased by 4 degrees C. For 8 neurones there was a linear relation between stimulus intensity and responses. (3) Several different factors which could explain the important modification of neuronal responses in VB complex of arthritic rats by comparison with normal are proposed in the discussion.
通过向大鼠尾部注射丁酸分枝杆菌使其患多关节炎，以此作为研究“慢性疼痛”的模型。与在相同麻醉条件下研究的正常大鼠相比，这类大鼠丘脑腹侧基底核神经元对躯体刺激的单位反应发生了显著改变。（1）本研究仅考虑感受野位于炎症区域的神经元（33只大鼠中有168/194个）。168个中仅通过轻刷激活的27个表现出经典的薄束核反应特性；仅20/168个仅由强烈皮肤刺激激活，168个中已被轻度皮肤刺激激活的13个在刺激强度增加时放电增强。相比之下，许多单位（108/168）被施加于关节或相邻皮肤区域的轻度刺激所兴奋（82个由关节运动和/或关节处的轻度侧向压力驱动，26个由轻刷重叠皮肤驱动）；这些反应呈现非典型特征，并表现出异常模式，具有持续时间比刺激长数倍的非常长的后放电。（2）在另外20只患关节炎的大鼠中，对34个对关节刺激有反应的神经元获得了经皮电刺激（TES）和/或有害热刺激的反应。（a）18个经皮电刺激测试的神经元中有16个潜伏期为25 - 100毫秒，阈值为1 - 4毫安（电击宽度2毫秒）。（b）由关节刺激激活的神经元经常对有害热（辐射或水浴）有反应。最初，在16个神经元中测试的它们的反应阈值比正常大鼠中“有害的”腹侧基底核神经元的阈值高约4摄氏度；然而，在对热敏感后，阈值降低了4摄氏度。对于8个神经元，刺激强度与反应之间存在线性关系。（3）讨论中提出了几个不同的因素，这些因素可以解释与正常大鼠相比，患关节炎大鼠腹侧基底核复合体中神经元反应的重要改变。
