[³H]-gentamicin labelling and gentamicin toxicity in <i>av6J</i> and <i>av3J</i> cochlear cultures.

<p>(A–D) Autoradiographs of [³H]-gentamicin uptake in <i>+/av6J</i> (A), <i>av6J/av6J</i> (B), <i>+/av3J</i> (C) and <i>av3J/av3J</i> (D) apical-coil hair cells. Arrowheads indicate outer hair cells, arrows indicate inner hair cells. [³H]-gentamicin uptake observed in the <i>av6J/av6J</i> mouse (B) is reduced relative to that in the <i>+/av6J</i> control (A). In contrast, <i>av3J/av3J</i> hair cells (D) completely fail to load with [³H]-gentamicin whilst <i>+/av3J</i> control loading (C) is similar to that observed for <i>+/av6J</i> hair cells (A). (E–H) Toluidine blue stained light micrographs of gentamicin treated cochlear cultures from <i>+/av6J</i> (E), <i>av6J/av6J</i> (F), <i>+/av3J</i> (G) and <i>av3J/av3J</i> (H) mice. Arrows indicate extruded hair cells. Whilst <i>+/av6J</i> (E), <i>av6J/av6J</i> (F) and <i>+/av3J</i> hair cells (G) are all sensitive to gentamicin, <i>av3J/av3J</i> hair cells (H) are resistant to this antibiotic. Scale bars = 20 µm.