Dynamic tether force measurements of the outer hair cells plasma membrane with optical tweezers

The mechanical characteristics of the outer hair cells (OHCs) plasma membrane was studied by forming tethers with optical tweezers. The average force to and from a plasma membrane tether at the lateral wall of the OHC was about 3.5 times greater than that at the basal end of the cell, consistent with the presence of a more extensive cytoskeleton support beneath the PM at the site of the lateral wall. The apparent viscosity of the PM was measured by pulling tethers at different rates while continuously recording the tether force, and was estimated in the range of 13-33 pN*s/micrometers .