Encoding of amplitude modulations by auditory neurons of the locust: influence of modulation frequency, rise time, and modulation depth.

ABSTRACT: Using modulation transfer functions (MTF), we investigated how sound patterns are processed within the auditory pathway of grasshoppers. Spike rates of auditory receptors and primary-like local neurons did not depend on modulation frequencies while other local and ascending neurons had lowpass, bandpass or bandstop properties. Local neurons exhibited broader dynamic ranges of their rate MTF that extended to higher modulation frequencies than those of most ascending neurons. We found no indication that a filter bank for modulation frequencies may exist in grasshoppers as has been proposed for the auditory system of mammals. The filter properties of half of the neurons changed to an allpass type with a 50% reduction of modulation depths. Contrasting to reports for mammals, the sensitivity to

SUBMITTER: Wohlgemuth S 

PROVIDER: S-EPMC3016238 | biostudies-literature | 2011 Jan

REPOSITORIES: biostudies-literature