Defference in physiological and mophological properties between jaw-closing and opening motoneurons

闭颌和张开运动神经元之间生理和形态学特性的差异

• 批准号: 14571777
• 负责人: INOUE Tomio
• 金额: $ 1.92万
• 依托单位: Showa University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14571777/
• 关键词: trigeminal; motoneuron; afterhyperpolarization; patch clamp; slice preparation; jaw-closing muscle; jaw-opening muscle; 拮抗筋

Whole cell patch clamp recordings were made from masseter motoneurons (MaMNs) and digastric motoneurons (DiMNs) in neonatal rat brainstem slice preparations to study firing properties of jaw-closing and opening motoneurons. Input resistance and membrane time constant of MaMNs were smaller than those of DiMNs. Amplitude of the post-spike medium-duration afterhyperpolarization (mAHP) in MaMNs was smaller than that of DiMNs and duration of the mAHP in NaMNs was shorter than that of DiMNs. Decay time constant of the mAHP tail current in MaMNs was shorter than that in DiMNs. Ca^<2+> influx producing the mAHP through activation of Ca^<2+>-activated K^+ channel was monitored using Ca^<2+> imaging, in the presence of apamin ? -agatoxin IVA, ? -conotoxin CV1A and Ni^<2+>. The slope of the relationship between firing frequency (f) and membrane depolarization (V) induced by injection of 1-s current pulses was steeper in MaMNs than the slope in DiMNs. The slope of the f-V relationship were correlated with amplitude and duration of the mAHP and the difference in the slope of the f-V relationship between MaMNs and DiMNs was abolished by apamin. We conclude that smaller and shorter mAHP in MaMNs results in steeper slope of the the f-V relationship, compared with DiMNs. Such firing properties of jaw-closing and opening motoneurons might contribute to transduction of masticatory drive signal from central pattern generator of mastication to appropriate activities of jaw-closing and opening muscles.

采用全细胞膜片钳技术记录新生大鼠咬肌运动神经元（MaMNs）和二腹肌运动神经元（DiMNs），研究咬肌运动神经元的放电特性。MaMNs的输入电阻和膜时间常数均小于DiMNs。MaMNs的峰后中时程后超极化（mAHP）幅度小于DiMNs，NaMNs的mAHP持续时间短于DiMNs。MaMNs中的mAHP尾电流衰减时间常数比DiMNs中的短。在apamin？- 蛇毒IVA，？- 芋螺毒素CV 1A和Ni^（2+）。放电频率（f）和膜去极化（V）之间的关系的斜率由注射1秒的电流脉冲诱导的MaMN比DiMN的斜率更陡。f-V关系的斜率与mAHP的幅度和持续时间相关，并且MaMNs和DiMNs之间的f-V关系的斜率的差异被apamin消除。我们的结论是，更小和更短的mAHP在MaMN的f-V关系的斜率更陡的结果，与DiMN相比。咀嚼运动中枢模式发生器的咀嚼驱动信号可能通过咀嚼运动神经元的这种放电特性传导到相应的咀嚼肌活动中。

项目成果

Masuda, Y.: "Influence of oro-facial sensory input on the output of the cortical masticatory area in the anestheitzed rabbit."Exp.Brain Res.. 146. 501-510 (2002)

Masuda, Y.：“麻醉兔子口面部感觉输入对皮质咀嚼区输出的影响。”Exp.Brain Res.. 146. 501-510 (2002)

斉藤茂: "感圧型咬合シートによる歯の疼痛の簡便な判定法-マルチブラケット装置装着に伴う痛みとレーザー照射による除痛効果-"Orthd Waves. 61. 31-39 (2002)

Shigeru Saito：“使用压敏咬合片确定牙齿疼痛的简单方法 - 佩戴多托槽装置的疼痛和激光照射的疼痛缓解效果 -”Orthd Waves 61. 31-39 (2002)。

Tsuruoka, M.: "Coeruleotrigeminal inhibition of nociceptive processing in the rat trigeminal subnucleus caudalis."Brain Res.. 993. 146-153 (2003)

Tsuruoka, M.：“Coeruleottrigeminal 对大鼠三叉神经尾核亚核中伤害性加工的抑制。”Brain Res.. 993. 146-153 (2003)

Inoue, T.: "Excitatory effects of noradrenaline on trigeminal motoneurons in rats."Dent.Jpn.. 38. 33-35 (2002)

Inoue, T.：“去甲肾上腺素对大鼠三叉神经运动神经元的兴奋作用。”Dent.Jpn.. 38. 33-35 (2002)

Masuda, Y.: "Influence of oro-facial sensory input on the output of the cortical masticatory area in the anesthelized rabbit."Exp.Brain Res.. 146. 501-510 (2002)

Masuda, Y.：“麻醉兔子口面部感觉输入对皮质咀嚼区输出的影响。”Exp.Brain Res.. 146. 501-510 (2002)