Study of the Action Potential in the Isolated Posterior Ampullar Receptor

Abstract

The posterior semicircular canal of frog was isolated to lead potential from the ampullar nerve. The ampullar receptor was stimulated with a device which could induce both ampullofugal and ampullopetal flows. By using an a.c. amplifier it was discovered that the posterior ampullar receptor was effectively stimulated by ampullofugal flow resulting in an increase in nerve impulse frequency, while an ampullopetal flow caused no response. When a d.c. amplifier was used to record responses on similar stimulation an ampullofugal stimulation caused a positive slow potential, whereupon an increase in nerve impulse frequency was observed. Whether or not this potential was in truth a biologic one was investigated utilizing Ba⁺⁺-ion. Pronounced influence from the Ba⁺⁺-ion showed that it was evidently a biologic one.