Comparing the electrophysiological effects of traumatic noise exposure between rodents.

Noise-induced hearing deficits are important health problems in the industrialized world. As the underlying physiological dysfunctions are not well understood, research in suitable animal models is urgently needed. Three rodent species (Mongolian gerbil, rat, and mouse) were studied to compare the temporal dynamics of noise-induced hearing loss after identical procedures of noise exposure.

Strain Comparison in Rats Differentiates Strain-Specific from More General Correlates of Noise-Induced Hearing Loss and Tinnitus.

Experiments in rodent animal models help to reveal the characteristics and underlying mechanisms of pathologies related to hearing loss such as tinnitus or hyperacusis. However, a reliable understanding is still lacking. Here, four different rat strains (Sprague Dawley, Wistar, Long Evans, and Lister Hooded) underwent comparative analysis of electrophysiological (auditory brainstem responses, ABRs) and behavioral measures after noise trauma induction to differentiate between strain-dependent trauma effects and more consistent changes across strains, such as frequency dependence or systematic temporal changes.

Dependence of the Startle Response on Temporal and Spectral Characteristics of Acoustic Modulatory Influences in Rats and Gerbils.

The acoustic startle response (ASR) and its modulation by non-startling prepulses, presented shortly before the startle-eliciting stimulus, is a broadly applied test paradigm to determine changes in neural processing related to auditory or psychiatric disorders. Modulation by a gap in background noise as a prepulse is especially used for tinnitus assessment. However, the timing and frequency-related aspects of prepulses are not fully understood.

Variation in acoustic overstimulation changes tinnitus characteristics.

Tinnitus often occurs after exposure to loud noise. This raises the question of whether repeated exposure to noise increases the risk of developing tinnitus. We thus studied tinnitus development after repeated acoustic overstimulation using startle and auditory brainstem-response techniques applied to Mongolian gerbils.

Stimulus-specific adaptation in field potentials and neuronal responses to frequency-modulated tones in the primary auditory cortex.

In order to structure the sensory environment our brain needs to detect changes in the surrounding that might indicate events of presumed behavioral relevance. A characteristic brain response presumably related to the detection of such novel stimuli is termed mismatch negativity (MMN) observable in human scalp recordings. A candidate mechanism underlying MMN at the neuronal level is stimulus-specific adaptation (SSA) which has several characteristics in common.