Hearing Assessment in Zebrafish During the First Week Postfertilization

Abstract

The zebrafish (Danio rerio) is a valuable vertebrate model for human hearing disorders because of many advantages in genetics, embryology, and in vivo visualization. In this study, we investigated auditory function of zebrafish during the first week postfertilization using microphonic potential recording. Extracellular microphonic potentials were recorded from hair cells in the inner ear of wild-type AB and transgenic Et(krt4:GFP) sqet4 zebrafish at 3, 5, and 7 days postfertilization in response to 20, 50, 100, 200, 300, and 400-Hz acoustic stimulation. We found that microphonic threshold significantly decreased with age in zebrafish. However, there was no significant difference of microphonic responses between wild-type and transgenic zebrafish, indicating that the transgenic zebrafish have normal hearing like wild-type zebrafish. In addition, we observed that microphonic threshold did not change with the recording electrode location. Furthermore, microphonic threshold increased significantly at all tested stimulus frequencies after displacement of the saccular otolith but only increased at low frequencies after displacement of the utricular otolith, showing that the saccule rather than the utricle plays the major role in larval zebrafish hearing. These results enhance our knowledge of early development of auditory function in zebrafish and the factors affecting hearing assessment with microphonic potential recording.

A profile of auditory‐responsive neurons in the larval zebrafish brain

“…It is unknown whether this pathway is developed in larval zebrafish, as most studies of hearing in zebrafish have looked at juveniles or adults (Cervi, Poling, & Higgs, ; Higgs et al, ; Higgs, Souza, Wilkins, Presson, & Popper, ; Mueller, ; Wang et al, ). The few studies assessing larval hearing have used microphonic potentials to gauge responses in the ears' hair cells (Lu & DeSmidt, ; Rohmann, Tripp, Genova, & Bass, ; Yao et al, ), and this work has shown responses to tones ranging from 20 Hz to 400 Hz as early as 3 days postfertilization (dpf) (Yao et al, ). By 5–6 dpf, larvae startle to tones up to 1,000 Hz, although these responses require extremely strong stimuli (Bhandiwad, Zeddies, Raible, Rubel, & Sisneros, ).…”

The Generation of Zebrafish Mariner Model Using the CRISPR/Cas9 System

“…At 7 dpf, larvae were fixed in 2% paraformaldehyde solution overnight and treated with 0.5% Triton X‐100 for 2 hr to permeabilize the tissue and dissolve the otoliths. Hair cell stereocilia were then labeled with Alexa Fluor® 546‐phalloidin (1:50 dilution, Thermo Fisher Scientific, Grand Island, NY) overnight (Grati et al, ; Yao et al, ). After larvae were embedded in an anti‐fade solution on a slide, stereocilia of hair cells in the saccule were scanned and 3D reconstructed using a Nikon C1 confocal microscope, and hair cell stereociliary bundles were then quantified with Nikon NIS‐Elements imaging software (Yao et al, ).…”

The alcohol‐sensitive period during early octavolateral organ development in zebrafish (Danio rerio)

“…Each fish was embedded dorsal side up on a MatTek Petri dish containing 1.8% low melting agarose and 0.045% phenol red for color visualization of the agarose. Buffered 0.009% MS‐222 commonly used for electrophysiological recordings was added to immobilize larvae (Trapani and Nicolson, ; Lu and DeSmidt, ; Ricci et al, ; Olt et al, ; Yao et al, ). The agarose covering the right dorso‐lateral side of the fish was removed with a 31.5 gauge syringe needle in order to position both a recording electrode and a stimulus probe.…”