Auditory nerve recordings in Xenopus laevis

Abstract

The South African clawed frog X. laevis communicates using a rich repertoire of underwater calls made up of clicks. Two calls, rapping and ticking, differ only by interclick interval [Tobias et al., PNAS (1998)]. To begin to explore rate coding in the auditory system, extracellular recordings were obtained in vivo from the auditory nerve of frogs stimulated with both pure tones and recorded calls. To avoid problems of impedance matching, acoustic stimuli were delivered via vibration-excited probe directly to the frog’s tympanum. Preferred frequencies across the population of 104 recorded fibers (taken from 5 females) fell into 2 or 3 groups: 1500, 600, and 200 Hz. Cells of all preferred frequencies fired in phase with clicks of the various calls. [Work supported by an NSF graduate fellowship to TME.]