In vivo patch-clamp analysis of developmental changes in the spinal nociceptive circuit.

脊髓伤害性回路发育变化的体内膜片钳分析。

基本信息

批准号：
18613009
负责人：
FURUE Hidemasa
金额：
$ 2.62万
依托单位：
Kyushu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18613009/
关键词：
synaptic transmission nrimary afferent spinal cord neuronal circuit C fiber electrophysiology neuron mechanoreceptor パッチクランプ in vivo 感覚痛覚伝達電気生理脊髄

项目摘要

Developmental changes in the spinal nociceptive synaptic transmission were examined using slice and in vivo patch-clamp recordings. In transverse spinal cord slices of young and adult rats at lumbar spinal levels with an attached dorsal root, electrical dorsal root stimulation was applied to record the evoked-synaptic responses in substantia gelatinosa (SG, lamina II of the spinal cord)and deep lamina (lamina III-IV) neurons. In the in vivo patch-clamp analysis, patch electrodes were inserted into the SG at the spinal level of L3-L5 after a thoracolumbar laminectomy was performed under urethane anesthesia. Whole-cell recordings were obtained from SG neurons, and then modality-dependent synaptic responses evoked by cutaneous natural mechanical stimuli applied to the ipsilateral hind limb were recorded. In adult rats, monosynaptic Aβ and C fiber-evoked EPSCs were elicited in SG neurons. Additionally, monosynapitc Aβ fiber-evoked EPSCs were evoked in the deeper lamina neurons but not in SG neurons. In young rats, on the other hand, monosynaptic Aβ fiber-evoked EPSCs were observed in SG neurons in addition to Aβ and C fiber-evoked responses. In the in vivo patch-clamp analysis, pinch stimulation elicited a barrage of EPSCs in SG neurons in young and adult rats. Even in SG neurons that received synaptic inputs from only Aβ fibers, pinch stimulation evoked a barrage of EPSCs. Most deep neurons in adult rats responded to touch stimulation. The present results suggest that Aβ fibers, in addition to Aδ and C fibers, convey noxious mechanical information to SG neurons in young rats. In adult rats with further development of neuronal circuits in the spinal dorsal horn, innocuous mechanical synaptic responses are mediated only through Aβ fibers in deep lamina neurons.

使用切片和体内膜片钳记录检查脊髓伤害性突触传递的发育变化，在具有附加背根的年轻和成年大鼠的腰椎水平脊髓切片中，施加电背根刺激以记录诱发的刺激。 -体内膜片钳中的胶质质（SG，脊髓 II 层）和深层（III-IV 层）神经元的突触反应。分析中，在乌拉坦麻醉下进行胸腰椎椎板切除术后，将贴片电极插入 L3-L5 脊髓水平的 SG，从 SG 神经元获得全细胞记录，然后由皮肤自然机械刺激诱发模态依赖性突触反应。在成年大鼠中，记录了应用于同侧后肢的 SG 神经元中的单突触 Aβ 和 C 纤维诱发的 EPSC。单突触 Aβ 纤维诱发的 EPSC 在较深的层神经元中被诱发，但在 SG 神经元中没有诱发，另一方面，除了 Aβ 和 C 纤维诱发的反应之外，在 SG 神经元中还观察到单突触 Aβ 纤维诱发的 EPSC。在体内膜片钳分析中，挤压刺激会在年轻和成年大鼠的 SG 神经元中引发大量 EPSC，甚至在接受突触的 SG 神经元中也是如此。仅来自 Aβ 纤维的输入，捏刺激会引起大量 EPSC 响应，目前的结果表明，除了 Aδ 和 C 纤维外，Aβ 纤维还向年轻的 SG 神经元传递有害的机械信息。在脊髓背角神经元回路进一步发育的成年大鼠中，无害的机械突触反应仅通过深层神经元中的 Aβ 纤维介导。