d-Tubocurarine and berbamine protect lateral line hair cells in zebrafish from gentamicin and neomycin induced damage. Zebrafish were treated with: (A,G,M,S) E3 alone (B) 6.25 μM neomycin, or (C–F) 25, 12.5, 6.25, or 3.1 μM of dTC plus 6.25 μM neomycin, (H) 10 μM gentamicin, (I–L) 25, 12.5, 6.25, or 3.1 μM of dTC plus 10 μM gentamicin, (N) 6.25 μM neomycin, (O–R) 25, 12.5, 6.25, or 3.1 μM of berbamine plus 6.25 μM neomycin, (T) 10 μM gentamicin, (U–X) 25, 12.5, 6.25, or 3.1 μM of berbamine plus 10 μM gentamicin. Neuromasts were pre-stained with 3 μM Yo-Pro1. n > 3 independent experiments with at least 3 fish per well. Images were obtained with a 40X objective. Scale bar = 25 μm.

d-Tubocurarine and berbamine protect cochlear OHCs from gentamicin damage. Protection assay using cultures prepared from CD-1 mice at postnatal day 2 (P2). Cultures were stained with TRITC-phalloidin at the end of the experiment allowing visualization of the actin-rich stereocilia. (A) Control culture incubated for 48 h in the presence of medium alone. The sensory hair cell loss shown in (B) caused by 48 h incubation with 5 μM gentamicin can be prevented by co-incubation with 25 μM dTC (C) or 20 μM berbamine (D). Cells incubated in 50 μM dTC in the absence of gentamicin were not damaged (E), whereas 30 μM berbamine resulted in widespread loss of IHCs, OHCs and other cell types (F). Scale bar = 50 μm.

d-Tubocurarine and berbamine reduce the loading of GTTR. (A) dTC and berbamine significantly reduced the fluorescent intensity of 0.2 μM GTTR compared to DMSO controls (***p < 0.001). No significant difference was seen between the reduction by dTC and berbamine. Fluorescent intensity was measured in arbitrary units (a.u.). Error bars are ±SEM. (B–D) Representative images taken following 10 min GTTR exposure in DMSO, dTC and berbamine. Scale bar = 50 μm.