Recovery of otoacoustic emissions after high-level noise exposure in the American bullfrog

Abstract

There was an error published in J. Exp. Biol. 217, pp. 1626-1636 In Fig. 3, panel A has a duplicated line graph and the keys in panels B and D are incorrect. The correct figure is printed below. The cubic distortion product (DP) 2f 1 -f 2 recorded from the bullfrog ear with primary f 1 and secondary f 2 frequencies as shown. In this example, secondary levels are 10 dB lower than primary levels. (B) Plot of cubic distortion product otoacoustic emission (DPOAE) levels from the right ear (ipsilateral) versus secondary frequency (f 2 ). DPOAE levels are in decibels relative to 1 V rms (dBV). The plot depicts DPOAE levels recorded before (solid symbols) and 24 h after (open symbols) 150 dB SPL broad-band noise exposure. Filled and open squares represent corresponding pre-and post-noise levels, respectively. At each frequency, the primary stimulus was held constant at 80 dB SPL and the secondary stimulus level was presented at equal strength (solid squares, L 1 =L 2 ) and then with secondary levels 10 dB lower than primary levels (solid circles, L 1 >L 2 ). Noise level measurements were taken and averaged on either side of the peak DPOAE level immediately before and after noise exposure, with each ear tested and averaged over three presentations. Dashed lines represent noise floor. (C) Cubic DPOAEs (L 1 >L 2 ) from the right ear were tested before (day 0) and 1, 2, 5, 6, 7 and 8 days after noise exposure. Dashed lines represent noise floor. (D) Plot of the DPOAE shifts at each frequency tested before (0 days) and following (1, 2, 5, 6, 7 and 8 days) a 20 h noise exposure. The DPOAE shift was calculated as the difference in pre-exposure and post-exposure DPOAE levels.We apologise to the authors and readers for this omission. DP level (dBV) day 0 DP level (dBV) day 1 DP level (dBV) day 2 DP level (dBV) day 5 DP level (dBV) day 6 DP level (dBV) day 7 DP level (dBV) day 8Pre-exposure, L1>L2 Pre-exposure, L1=L2 Post-exposure, L1>L2 Post-exposure, L1=L2 DP level (dBV) day 0 DP level (dBV) day 1 DP level (dBV) day 2 DP level (dBV) day 5 DP level (dBV) day 7 DP level (dBV) day 8 B 2221

Single-cell atlas comparison across vertebrates reveals evolution of auditory cell types and mechanisms for hair cell regeneration

“…Intriguingly, bulk transcriptome data indicate that the inner ear in Xenopus rather than mouse exhibited signi cantly higher expression of well-known hair cell regeneration-related genes Atoh1, Tbx2, Insm1, Lgr5, and Bdnf (Fig. 1E), con rming a potential association with the high regenerative capacity observed in frog inner ear 13 . The Atoh1 gene, whose expression ceasing around postnatal day 3-7 36 , was rstly used for induction of hair cell regeneration in mammal in 2005 45 .…”

“…In contrast, non-mammalian vertebrates commonly exhibit robust natural capacities for hair cell regeneration and restoration of hearing function [11][12][13] . The observed differences in regeneration capacities among vertebrates stand in contrast to their evolutionary positions.…”

“…The Anura amphibians, including frogs or toads (Xenopus), were popular and classic models for studying the inner ear structure, development, neural circuits, auditory behaviors, and hair cell regeneration 22 . The hair cells in bullfrog can be regenerated after acoustic trauma or ototoxic drug exposure 13,23 . Xenopus can regenerate its hair cells as well as its whole organs, like larval tail, limbs, and spinal cord, after damage or cell deaths 24 .…”