NEURONAL RESPONSIVENESS IN THE VENTROBASAL THALAMIC COMPLEX OF RATS WITH AN EXPERIMENTAL PERIPHERAL MONONEUROPATHY
NEURONAL RESPONSIVENESS IN THE VENTROBASAL THALAMIC COMPLEX OF RATS WITH AN EXPERIMENTAL PERIPHERAL MONONEUROPATHY
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DOI：
10.1152/jn.1990.64.5.1537
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发表时间：
1990-11-01
影响因子：
2.5
通讯作者：
GAUTRON, M
中科院分区：
文献类型：
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作者：
GUILBAUD, G;BENOIST, JM;GAUTRON, M
1.在中度气体麻醉（33%O_2 - 66%N_2O + 0.5/0.6%氟烷）下，在大鼠（n = 42）的丘脑腹侧基底（VB）复合体中进行单单位记录，该大鼠在2-3周前通过在总坐骨神经周围进行4次松散结扎而产生单神经病。在记录之前，对机械和热刺激的三种行为伤害性测试显示，这些大鼠表现出明显的痛觉过敏（对伤害性刺激的过度反应）和异常性疼痛（对通常被认为是无害的刺激的伤害性反应）。2.神经元，其特征在于手动机械刺激的反应，被分为两组：组1的神经元完全驱动的光触觉刺激施加到感受野（RF），严格对侧的记录网站;和组2的神经元，驱动的持续捏施加到一个大的RF，往往是双边的。3.从神经元的总群体（n = 386），只有那些响应于施加到一个后爪的刺激进行了研究;这些细胞的比例（35-40%）是相当的，在每两个VB：n = 93/262和44/124，在VB对侧（VBc）和同侧（VBi）受损的神经，分别。各功能组神经元（组1或组2）的比例在每侧也相似。4.对于所有组1神经元，RF大小与正常大鼠中观察到的相当。在VBi的这些神经元的反应提出了经典的响应模式观察到的VB神经元参与触摸传输，VBc组1神经元与RFs在隐（Sa）的领土。与此形成鲜明对比的是，VBc组1神经元的活动与RF在坐骨神经（Sc）的领土表现出几个异常：更高的背景活动，褪色的反应与重复刺激，和后放电超过所施加的刺激。5.与正常大鼠一样，52%的VB组2神经元表现出双侧对称的RF。它们对机械刺激的反应往往更大的刺激施加到受影响的爪子，其中一些可以激活适度的压力，这只爪子。热反应也说明了损伤侧的敏感性显著增加，与正常值相比，这些第2组神经元对热刺激的激活阈值降低了4-6摄氏度。此外，这些神经元对将损伤的爪子浸入10摄氏度的水浴中做出反应，当施加到对侧爪子时，这种刺激无效。（250字处删节）
1. Single-unit recordings were made, under moderate gaseous anesthesia (33% O2-66% N2O + 0.5/0.6% halothane), in the ventrobasal (VB) thalamic complex of rats (n = 42) with a mononeuropathy created 2-3 wk beforehand, by four loose ligatures around the common sciatic nerve. Before the recording session, three behavioral nociceptive tests to both mechanical and thermal stimuli revealed that these rats exhibited clear hyperalgesia (excessive reactions to noxious stimuli) and allodynia (nociceptive reactions to stimuli usually perceived as nonnoxious). 2. Neurons, characterized by their responses to manual mechanical stimuli, were classified into two groups: group 1 neurons exclusively driven by light tactile stimuli applied to the receptive field (RF), strictly contralateral to the recording site; and group 2 neurons, driven by sustained pinch applied to a large RF, often bilateral. 3. From the total population of neurons (n = 386), only those responding to stimuli applied to one posterior paw were studied; the proportion (35-40%) of these cells was comparable in each of the two VB: n = 93/262 and 44/124 in the VB contralateral (VBc) and ipsilateral (VBi) to the damaged nerve, respectively. The proportions of each functional group of neurons (group 1 or 2) were also similar on each side. 4. For all group 1 neurons the RFs size was comparable to that observed in normal rats. In the VBi the responses of these neurons presented the classical response pattern observed for VB neurons involved in touch transmission, as did the VBc group 1 neurons with RFs in the saphenous (Sa) territory. In sharp contrast, activities of VBc group 1 neurons with RFs in the sciatic (Sc) nerve territory exhibited several abnormalities: higher background activity, fading of the response with repetitive stimulation, and afterdischarges outlasting the applied stimulus. 5. As in normal rats, 52% of VB group 2 neurons exhibited bilateral symmetrical RFs. Their responses to mechanical stimuli were often greater for stimuli applied to the affected paw, and some of them could be activated by moderate pressure to this paw. Heat responses also illustrated the profound increased sensitivity of the lesioned side, and the activation threshold to thermal stimulation of these group 2 neurons was lowered by 4-6 degrees C compared to normal values. In addition, these neurons responded to immersion of the lesioned paw in a 10 degrees C water bath, a stimulus that was ineffective when applied to the opposite paw.(ABSTRACT TRUNCATED AT 250 WORDS)