title: Resting discharge and response dynamics of horizontal semicircular canal afferents of the toadfish, Opsanus tau.
abstract: The response dynamics of 66 primary afferents of the horizontal semicircular canal were studied in the toadfish using sinusoidal, rotational stimuli from 0.001-10 Hz at amplitudes of 5-100 degrees/sec. Twelve afferents were also tested to constant velocity trapezoids. Responses to sinusoids were used to classify afferents into 3 broad groups: (1) low-gain afferents that maintain a relatively linear response re: stimulus velocity across most of the frequency and amplitude spectra tested; (2) high-gain afferents that have a velocity sensitivity but also show a high-frequency gain enhancement and phase advance; and (3) so-called acceleration afferents that have a response more in phase with stimulus acceleration than velocity across the tested bandwidth. The afferent's background discharge was examined in relation to its rotational response. Low-gain afferents have regular spacing of interspike intervals. High-gain and acceleration afferents have a widely variable discharge regularity that is apparently unrelated to their rotational responses. Input/output transfer models were fit to the response data to describe the low- and high-pass filtering properties of the 3 afferent groups.
authors.affiliation: Department of Otolaryngology, Oregon Health Sciences University, Portland 97201.
authors.forename: R
authors.initials: R
authors.lastname: Boyle
authors.forename: S M
authors.initials: SM
authors.lastname: Highstein
mesh_terms: D000818:Animals; D005260:Female; D005399:Fishes / Q000502:physiology*; D008297:Male; D008959:Models, Neurological; D009475:Neurons, Afferent / Q000502:physiology*; D012146:Rest; D012399:Rotation; D012665:Semicircular Canals / Q000294:innervation*