Characteristics of glutamate-evoked temporomandibular joint afferent activity in the rat
Characteristics of glutamate-evoked temporomandibular joint afferent activity in the rat
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DOI：
10.1152/jn.2001.85.6.2446
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发表时间：
2001-06-01
影响因子：
2.5
通讯作者：
Hu, JW
中科院分区：
文献类型：
--
作者：
Cairns, BE;Sessle, BJ;Hu, JW
大鼠颞下颌关节（TMJ）囊内注射谷氨酸（Glu）可反射性地引起下颌肌肌电（EMG）活动的延长，但谷氨酸激活TMJ传入的特点尚未见报道。在本研究中，我们研究了谷氨酸注射到颞下颌关节囊上的下颌肌肌电活动和细胞外记录活动的单一三叉神经传入，在颞下颌关节组织中的感受野和逆向识别的预测脑干尾侧亚核（Vc）在两种性别的大鼠。谷氨酸（0.05-1.0 M，10穆尔）注射到颞下颌关节囊诱发的EMG活动在剂量相关的方式，然而，在0.5和1.0 M的浓度，谷氨酸诱发的二腹肌反应在雌性大鼠比雄性大鼠。在实验中，下颌肌肉肌电图和传入活动被同时记录，谷氨酸（0.5 M，10穆尔）注射到颞下颌关节囊诱发活动的下颌肌肉，以及在27（26 A δ和1 C-纤维传入）的34三叉神经传入，可以通过钝机械刺激颞下颌关节组织激活。在这些实验中，谷氨酸诱发的颌肌活动显着增加6分钟后，谷氨酸注射，而传入活动显着增加，仅在第一分钟后，谷氨酸注射。谷氨酸诱发的传入活动与传导速度呈负相关，
Injection of glutamate into the rat temporomandibular joint (TMJ) capsule can reflexly induce a prolonged increase in the electromyographic (EMG) activity of the jaw muscles, however, the characteristics of TMJ afferents activated by glutamate have not been investigated. In the present study, we examined the effect of glutamate injection into the TMJ capsule on jaw muscle EMG activity and the extracellularly recorded activity of single trigeminal afferents that had receptive fields in the TMJ tissue and antidromically identified projections to the brain stem subnucleus caudalis (Vc) in rats of both sexes. Glutamate (0.05-1.0 M, 10 mul) injection into the TMJ capsule evoked EMG activity in a dose-related manner; however, at concentrations of 0.5 and 1.0 M, glutamate-evoked digastric muscle responses were greater in female than in male rats. In experiments where jaw muscle EMG and afferent activity were recorded simultaneously, glutamate (0.5 M, 10 mul) injection into the TMJ capsule evoked activity in the jaw muscles as well as in 27 (26 A delta and 1 C-fiber afferent) of 34 trigeminal afferents that could be activated by blunt mechanical stimulation of the TMJ tissue. In these experiments, glutamate-evoked jaw muscle activity was significantly increased for 6 min after the glutamate injection, whereas afferent activity was significantly increased only during the first minute after the glutamate injection. The glutamate-evoked afferent activity was inversely related to conduction velocity and, in afferents with conduction velocities