4pPP7. Tuning in primary saccular afferents of the toadfish (Opsanus tau) revealed by REVCOR analysis.

Session: Thursday Afternoon, December 5

Time: 3:30

Author: R. R. Fay
Location: Parmly Hearing Inst., Chicago, IL
Author: P. Edds-Walton
Location: Marine Biological Lab., Woods Hole, MA 02543
Author: S. Highstein
Location: Marine Biological Lab., Woods Hole, MA 02543


Male toadfish vocalize (e.g., the ``boatwhistle'' -f[inf 0] from 100 to 250 Hz) to attract females during mating season. This experiment investigates whether the frequency response of primary saccular afferents is adequate to encode these vocalizations. Whole-body oscillation (0.1--300 nm displacements) was delivered by a three-dimensional shaker system driven by noise with a flat spectrum between 50 and 1000 Hz. Stimuli were presented along three orthogonal axes (side--side, front--back, and up--down). Spikes were time stamped with 0.1-ms resolution. REVCOR functions were averaged accelerometer recordings of the noise triggered by spikes for 51.2 ms before and after each spike. This estimated the impulse response of the linear filtering that preceded spike generation. An FFT of the impulse responses estimated an afferent's filter shape. Impulse responses obtained were damped oscillations having a major peak indicating the magnitude and direction of excitatory acceleration. In general, filter shapes are low-pass within the frequency range investigated with corner frequencies varying between 120 and 350 Hz. These and other data [P. Edds-Walton and R. Fay, Biol. Bull. 189, 211--212 (1995)] show that the saccule's response to acoustic particle motion can account for the reception of ``boatwhistle'' vocalizations. [Work supported by the NIH, NIDCD.]

ASA 132nd meeting - Hawaii, December 1996