title: Exposure and direct stimulation of the semicircular canal cupula.
abstract: The ampullary wall of the posterior semicircular canal was isolated from the frog, cut and the cupula exposed in frog Ringer's solution. The cupula was stimulated by depression with a fine glass micropipette. Three points on the cupula were selected for depression: point A, the lowest point on the midline of the cupula surface on the utricular side; point B, the uppermost on the midline of the same surface; and point C, in the middle of the lateral surface of the cupula. Depression at points A and B was toward the canal, whereas depression at point C was toward the centre of the cupula. The amount of depression was controlled by a micromanipulator. At point A, the minimum depression facilitating the posterior canal action potential was 1 micron; at point B, a greater amount of depression was needed to produce the action potential. Even a large amount of depression at point C resulted in only a small action potential, possibly because the direction of the sensory cell polarity is along the long axis of the canal.
authors.forename: M
authors.initials: M
authors.lastname: Suzuki
authors.forename: Y
authors.initials: Y
authors.lastname: Harada
mesh_terms: D000818:Animals; D005071:Evoked Potentials; D009433:Neural Inhibition; D010812:Physical Stimulation; D011892:Rana catesbeiana; D012665:Semicircular Canals / Q000294:innervation*; D011984:Sensory Receptor Cells / Q000502:physiology; D009435:Synaptic Transmission