[Effects of veratridine on labyrinth receptors in the frog]

The action of the veratrum alkaloid veratridine has been tested on the sensory apparatus of the frog semicircular canals. Intracellular and extracellular recordings of the electrical responses evoked by sinusoidal mechanical stimulations of the ampullar organ could not reveal an action of the drug on the hair cells whereas the onset of the impulse discharge at the encoder of the afferent nerve fibres is largely facilitated by veratridine. The mechanism of the drug action is discussed.