Auditory Input to CNS Is Acquired Coincidentally with Development of Inner Ear after Formation of Functional Afferent Pathway in Zebrafish

Habituation of the C-Start Response in Larval Zebrafish Exhibits Several Distinct Phases and Sensitivity to NMDA Receptor Blockade

“…Although there is evidence of synaptic connectivity between the 8 th nerve auditory input and the M-cell as early as 40 hpf [37], [38], we did not observe an escape response until 4 dpf, as previously reported [44]. Also similar to the findings of Best and colleagues [32], who measured auditory-elicited escape movements, we found that a 200 Hz tone was the most effective in evoking the C-start in larval zebrafish.…”

Manipulation of BK channel expression is sufficient to alter auditory hair cell thresholds in larval zebrafish

“…Consistent with prior studies using similar stimulation and recording methods (Starr et al, 2004;Tanimoto et al, 2009;Lu and DeSmidt, 2013), and of behavioral audiograms (Bhandiwad et al, 2013), wildtype larvae were responsive to vibratory stimuli over the range of frequencies tested (175-500 Hz, Fig. 2).…”

“…Microphonic potentials can be recorded from the saccule of developing zebrafish as young as 2 dpf (Tanimoto et al, 2009;Lu and DeSmidt, 2013) and are a valuable tool for determining the effect of mutations or MO treatments on auditory function (Lu and DeSmidt, 2013). Here, we used this larval zebrafish model to test the functional implications of manipulating the expression of BK channels encoded by two slo1 genes on hair cell auditory thresholds.…”

“…In this report, we show that interference with the normal expression of individual slo1 genes is sufficient to increase auditory thresholds in zebrafish larvae and that changes in BK channel expression are a direct mechanism for regulation of peripheral hearing sensitivity among fishes. Saccular microphonic potentials were recorded from the otic vesicles of zebrafish larvae at 3 dpf, a time point by which the auditory circuit is functional (Tanimoto et al, 2009). Although saccular auditory thresholds decrease over 3-7 dpf as the hair cell population increases in number (Lu and DeSmidt, 2013), we did not want to delay our recordings until a later time point because MOs are most effective up to 3 dpf (Bill et al, 2009).…”

“…Following previous studies of hearing in larval zebrafish, a vibratory particle motion-dependent stimulus was used to stimulate the opening of mechanotransduction channels that lead to the encoding of auditory stimuli by hair cells in the inner ear (Starr et al, 2004;Tanimoto et al, 2009;Lu and DeSmidt, 2013). Particle motion is an appropriate stimulus for studying inner ear function at the 3 dpf time point we chose because the zebrafish inner ear is not yet capable of mature pressure detection until >56 dpf, when a connection to the swim bladder made through specialized bones known as the Weberian apparatus has fully developed and ossified (Grande and Young, 2004).…”