Noise-induced hearing loss induces loudness intolerance in a rat Active Sound Avoidance Paradigm (ASAP)

Abstract

Hyperacusis is a loudness hypersensitivity disorder in which moderate-intensity sounds are perceived as extremely loud, aversive and/or painful. To assess the aversive nature of sounds, we developed an Active Sound Avoidance Paradigm (ASAP) in which rats altered their place preference in a Light/Dark shuttle box in response to sound. When no sound (NS) was present, rats spent more than 95% of the time in the Dark Box versus the transparent Light Box. However, when a 60 or 90 dB SPL noise (2–20 kHz, 2–8 kHz, or 16–20 kHz bandwidth) was presented in the Dark Box, the rats’ preference for the Dark Box significantly decreased. Percent time in the dark decreased as sound intensity in the Dark Box increased from 60 dB to 90 dB SPL. Interestingly, the magnitude of the decrease was not a monotonic function of intensity for the 16–20 kHz noise and not related to the bandwidth of the 2–20 kHz and 2–8 kHz noise bands, suggesting that sound avoidance is not solely dependent on loudness but the aversive quality of the noise as well. Afterwards, we exposed the rats for 28 days to a 16–20 kHz noise at 102 dB SPL; this exposure produced a 30–40 dB permanent threshold shift at 16 and 32 kHz. Following the noise exposure, the rats were then retested on the ASAP paradigm. High-frequency hearing loss did not alter Dark Box preference in the no-sound condition. However, when the 2–20 kHz or 2–8 kHz noise was presented at 60 or 90 dB SPL, the rats avoided the Dark Box significantly more than they did before the exposure, indicating these two noise bands with energy below the region of hearing loss were perceived as more aversive. In contrast, when the 16–20 kHz noise was presented at 60 or 90 dB SPL, the rats remained in the Dark Box presumably because the high-frequency hearing loss made 16–20 kHz noise less audible and less aversive. These results indicate that when rats develop a high-frequency hearing loss, they become less tolerant of low frequency noise, i.e., high intensity sounds are perceived as more aversive and should be avoided.

Mechanisms underlying auditory processing deficits in Fragile X syndrome

“…While sound hypersensitivity due to hearing loss or FMRP deficiency are likely to be mechanistically distinct, there are well‐developed assays for assessing sound sensitivity following hearing loss that can be applied to FXS and ASD models. Potential approaches include operant conditioning paradigms that assess perceptual decision making, which likely engage a more extensive range of auditory structures than startle‐based measures, or innate place‐preference paradigms that reflect the aversive nature of sounds without extensive training or conditioning …”

“…Potential approaches include operant conditioning paradigms that assess perceptual decision making, [169][170][171] which likely engage a more extensive range of auditory structures than startle-based measures, or innate place-preference paradigms that reflect the aversive nature of sounds without extensive training or conditioning. 172,173…”

Pathological Changes in the Inner Ear in Experimental Modeling of Sensorineural Hearing Loss in Animals

“…В последние годы возобновился интерес к экспе-риментальным работам по изучению патологии внутреннего уха. Публикации по этому направ-лению в доступных нам источниках принадлежат, преимущественно, зарубежным авторам [4,5,6]. Безусловно, в отечественной науке предстоит восполнить этот пробел, и особое место при этом принадлежит экспериментальным исследовани-ям с изучением слуховых структур на клеточном уровне.…”

Mechanisms of high-intensity sound exposure on inhibiting hippocampal long-term potentiation: role of brain-derived neurotrophic factor

“…Loud sounds can damage cochlear hair cells and is currently the leading cause of permanent hearing loss and tinnitus (Le et al, 2017). Even prolonged exposure to non-traumatic noise has adverse effects on the auditory processing (Eggermont et al, 2017) and exposure to moderate to high-intensity sound triggers behavior responses resulting in the avoidance of the sound source (Manohar et al, 2017), a protective measure to avoid damage to auditory hair cells. Indeed, loud sounds are stressors that lead to the activation of the HPA axis, leading to increased secretion of corticosterone (Helfferich and Palkovits, 2003;Burrow et al, 2005).…”