The behavioral response of mice to gaps in noise depends on its spectral components and its bandwidth

Abstract

The purpose of these experiments was to determine whether detecting brief decrements in noise level ("gaps") varies with the spectral content and bandwidth of noise in mice as it does in humans. The behavioral effect of gaps was quantified by their inhibiting a subsequent acoustic startle reflex. Gap durations from 1 to 29 ms were presented in five adjacent 1-octave noise bands and one 5-octave band, their range being 2 kHz to 64 kHz. Gaps ended 60 ms before the startle stimulus (experiment 1) or at startle onset (experiment 2). Asymptotic inhibition was greater for higher-frequency 1-octave bands and highest for the 5-octave band in both experiments, but time constants were related to frequency only in experiment 1. For the lowest band (2-4 kHz) neither noise decrements (experiment 1 and 2) nor increments (experiment 3) had any behavioral consequence, but this band was effective when presented as a pulse in quiet (experiment 4). The lowest frequencies in the most effective 1-octave band were one octave above the spectral region where mice have their best absolute thresholds. These effects are similar to those obtained in humans, and reveal a special contribution of wide band, high-frequency stimulation to temporal acuity.

Audiograms, gap detection thresholds, and frequency difference limens in cannabinoid receptor 1 knockout mice

“…It is possible that since the CB1R KO mice have a deficit in their audiogram from 8–24 kHz, they attend to lower frequencies better than CBA/CaJ mice. Ison et al (2005) found that gap detection performance increased as noise bands included frequencies of peak auditory sensitivity (i.e. 16 kHz) and concluded that mice have sensitive temporal acuity because they integrate information across frequency channels.…”

A Gap in Time: Extending our Knowledge of Temporal Processing Deficits in the HIV-1 Transgenic Rat

“…When the ISI is manipulated in gap-PPI, significant decreases in the startle amplitude are observed when the gap in background noise occurs between 30 to 200 msec prior to the startling stimulus (Ison et al 1998). Manipulations in the gap duration, as in gap threshold detection, consistently suggest that as gap duration increases, greater decreases in startle amplitude are observed (Ison et al 2005; Ison & Bowen, 2000). Additionally, prior research has established an inverse relationship between gap duration & ISI; as ISI increases, shorter gap durations produce significant inhibition (Ison 1982; Ison et al 1991; Leitner et al 1993).…”

Behavioral Models of Tinnitus and Hyperacusis in Animals

“…Presentation of the acoustic startle stimulus evokes a robust acoustic startle reflex (ASR); however, this reflex can be suppressed by insertion of a short duration silent gap in a continuous background sound just prior to the startle-eliciting stimulus (15, 43). In most studies, the ratio between the startle amplitude during trials in which the startle stimulus is presented alone (no-gap trials) and trials in which a gap is presented prior to the startle-eliciting stimulus (gap trials) is calculated as the GPIAS ratio.…”

“…Hickox and Liberman (61) demonstrated that gap detection deficits in noise-exposed rodents tested with the GPIAS paradigm are dependent on the interval between the silent gap and the startle-eliciting stimulus (43). Noise-exposed animals demonstrated GPIAS deficits only when the silent gap was placed immediately before the startle stimulus, but not when it was placed 80 ms before the startle stimulus.…”