Stimulation rate influences frequency tuning characteristics of inferior colliculus neurons in the little brown bat, Myotis lucifugus.

Abstract

Previous studies of frequency selectivity have investigated unit's responses to tonal stimuli widely separated in time to minimize inter-stimulus interaction. The results of such studies are assumed to accurately portray the cell's frequency selectivity. The goal of the present study was to investigate the frequency tuning characteristics of neurons in the inferior colliculus (IC) of the little brown bat (Myotis lucifugus) to tone pulses presented at higher rates. Our results indicate that the frequency response properties of central auditory neurons at low stimulation rates do not necessarily reflect the units' frequency response properties to sounds presented at higher, more behaviorally relevant rates. Specifically, IC neurons often show greater frequency selectivity at higher stimulation rates, which presumably confers a greater perceptual frequency resolution.