Suzuki Taku, Yoshihara Midori, Sakai Shogo, Tsuji Kojun, Nagoya Kouta, Magara Jin, Tsujimura Takanori, Inoue Makoto
Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata 951-8514, Japan.
Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata 951-8514, Japan.
Brain Res. 2018 Sep 1;1694:19-28. doi: 10.1016/j.brainres.2018.05.002. Epub 2018 May 3.
This study aimed to investigate whether the jaw-opening (JOR) and jaw-closing reflexes (JCR) are modulated during not only peripherally, but also centrally, evoked swallowing. Experiments were carried out on 24 adult male Japanese white rabbits. JORs were evoked by trigeminal stimulation at 1 Hz for 30 s. In the middle 10 s, either the superior laryngeal nerve (SLN) or cortical swallowing area (Cx) was simultaneously stimulated to evoke swallowing. The peak-to-peak JOR amplitude was reduced during the middle and late 10-s periods (i.e., during and after SLN or Cx stimulation), and the reduction was dependent on the current intensity of SLN/Cx stimulation: greater SLN/Cx stimulus current resulted in greater JOR inhibition. The reduction rate was significantly greater during Cx stimulation than during SLN stimulation. The amplitude returned to baseline 2 min after 10-s SLN/Cx stimulation. The effect of co-stimulation of SLN and Cx was significantly greater than that of SLN stimulation alone. There were no significant differences in any parameters of the JCR between conditions. These results clearly showed that JOR responses were significantly suppressed, not only during peripherally evoked swallowing but also during centrally evoked swallowing, and that the inhibitory effect is likely to be larger during centrally compared with peripherally evoked swallowing. The functional implications of these results are discussed.
本研究旨在调查张口反射（JOR）和闭口反射（JCR）是否不仅在周围性诱发吞咽期间，而且在中枢性诱发吞咽期间受到调制。对24只成年雄性日本白兔进行了实验。以1赫兹的频率对三叉神经进行30秒刺激来诱发JOR。在中间的10秒内，同时刺激喉上神经（SLN）或皮质吞咽区（Cx）以诱发吞咽。在中间和后10秒期间（即SLN或Cx刺激期间及之后），JOR的峰峰值幅度降低，且这种降低取决于SLN/Cx刺激的电流强度：SLN/Cx刺激电流越大，JOR抑制作用越强。Cx刺激期间的降低率明显大于SLN刺激期间。在10秒的SLN/Cx刺激后2分钟，幅度恢复到基线。SLN和Cx共同刺激的效果明显大于单独SLN刺激的效果。不同条件下JCR的任何参数均无显著差异。这些结果清楚地表明，JOR反应不仅在周围性诱发吞咽期间，而且在中枢性诱发吞咽期间均受到显著抑制，并且与周围性诱发吞咽相比，中枢性诱发吞咽期间的抑制作用可能更大。讨论了这些结果的功能意义。
