Electrophysiological study on trigemino-autonomic nerve reflex

The trigemino-autonomic nerve reflex, which plays an important role in the irritation syndrome in the oral region, was studied electrophysiologically and the following results were obtained.1) Reflex responses induced by trigeminal (infraorbital) nerve stimulation in cats and rats were observed at the cervical vagus trunk, the recurrent laryngeal nerve and the autonomic nerve fibers which distribute to the stomach, liver and kidney.2) The trigeminal stimulation facilitates the reflex of the superior laryngeal nerve to the recurrent laryngeal nerve.3) Aδ fibers served as afferent fibers in the trigemino -autonomic nerve reflex.4) In the dorsal vagus nucleus, an evoked response was observed during trigeminal stimulation.The above findings suggest that trigeminal nerve irritation, such as a surgical operation in the oral cavity, affects the various organs through a trigemino -autonomic nerve reflex.