Figure 11. Schematic summarizing entry and distribution of AGs in live LL HCs, and the effects of compounds that alter these processes.

AGs initially appear in the apical region, first labeling stereocilia, and kinocilia. They next appear in both diffuse and punctate intracellular pools. Different AGs exhibit different delivery rates to these different pools. When MET activity is blocked (e.g., by pretreatment and cotreatment with amiloride), all AGs fail to enter HCs. When dynamin-dependent endocytosis is inhibited (e.g., by Dynole 34-2 pretreatment), rapid delivery of AGs to the cytosol still occurs, but AG-labeled puncta are initially absent. Puncta do appear later. These late-forming puncta do not appear when both dynamin-dependent endocytosis and macroautophagy are inhibited (by pretreatment with Dynole 34-2 and pre- and cotreatment with the macroautophagy inhibitor 3-MA).