Figure 5

Hypothyroidism stiffens outer hair cells and supporting pillar cells. (A) Schematic of Atomic Force Microscopy (AFM) experiments. Organ of Corti explants were probed to determine surface mechanical properties of outer hair cells (OHCs) and supporting pillar cells (PCs) with an AFM that measures the relative movement of a laser reflected from a cantilever probe onto a photodiode detector. (B) Average Young’s modulus (mean ± s.e.m. kPa) was calculated for control and hypothyroid OHCs. OHCs in hypothyroid cochleae show a trend towards greater stiffness that is significant relative to control conditions at P3 (*p-value < 0.05). (C) Average Young’s modulus is significantly increased in hypothyroid PCs at E16 and P0. However, hypothyroid PCs have significantly reduced Young’s modulus by P5 relative to control conditions.