A method for controlled mechanical stimulation of single semicircular canals.

In the present technical report, we describe a method of mechanical stimulation for single semicircular canals that is reproducible, sensitive, and discrete. The mechanical stimulator is capable of delivering reliable controlled stimuli of different waveforms over a wide frequency range that produce endolymph movements and consequent cupula deflections without motion being imparted to the animal. The results of electrophysiological experiments where the responses from pigeon (Columba livia) single horizontal semicircular canal afferent fibers produced by mechanical stimulation across a broad frequency bandwidth are reported. Comparisons between afferent fiber responses elicited by natural yaw rotation and mechanical stimulation were conducted, with the results indicating that the two stimulation methods produced responses from the same afferent unit that could be equated in magnitude. In addition, results are described from several control experiments that were conducted in order to determine the efficacy of the mechanical stimulation technique.