Department of Toxicology, Hoshi University School of Pharmacy and Pharmaceutical Sciences, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan.
Synapse. 2012 Apr;66(4):369-71. doi: 10.1002/syn.20991. Epub 2011 Nov 3.
Vagal nerves modulate not only physical homeostasis, but also pain transmission. It has been reported that subdiaphragmatic vagal dysfunction causes visceral pain. However, the functional changes in nociceptive primary afferent fibers under such visceral pain soon after subdiaphragmatic vagal dysfunction are not fully documented. The present study was designed to investigate changes in the sensitivity of primary afferent fibers in the distal colon using a Neurometer which individually stimulates C, Aδ and Aβ fibers. Under stimulation with a handmade stimulus electrode in the distal colon, the current threshold in the distal colon was recorded with high reproducibility. Subdiaphragmatic vagotomy significantly decreased the current threshold of Aδ fibers in the distal colon with no change in the sensitivity of C or Aβ fibers. These results suggest that vagal dysfunction at an early stage may cause, at least in part, hypersensitivity of visceral Aδ fibers.
迷走神经不仅调节身体的生理平衡，还调节疼痛的传递。有报道称，膈下迷走神经功能障碍会导致内脏疼痛。然而，膈下迷走神经功能障碍后不久，伤害性初级传入纤维的功能变化尚未完全记录。本研究旨在使用 Neurometer 来研究初级传入纤维在远端结肠中的敏感性变化，Neurometer 可以单独刺激 C、Aδ 和 Aβ 纤维。在远端结肠的手工刺激电极刺激下，用 Neurometer 可以以高重复性记录远端结肠的电流阈值。膈下迷走神经切断术显著降低了远端结肠 Aδ 纤维的电流阈值，而 C 纤维或 Aβ 纤维的敏感性没有变化。这些结果表明，早期迷走神经功能障碍可能至少部分导致内脏 Aδ 纤维的高敏感性。
