Stiffness of ciliary bundles in inner ear

Range in frog saccule 0.132: in guinea-pig cochlea 0.72 pN/nm
Organism vertebrates
Reference Crawford AC, Fettiplace R. The mechanical properties of ciliary bundles of turtle cochlear hair cells. J Physiol. 1985 Jul364: 359-79. p.373 bottom paragraph & p.374 top paragraphPubMed ID4032304
Primary Source Ashmore, J. F. (1984). The stiffness of the sensory hair bundle of frog saccular hair cells. Journal of Physiology 350, 20P. & Strelioff, D. & Flock, A. (1984). Stiffness of sensory-cell hair bundles in the isolated guinea pig cochlea. Hearing Research 15, 19-28.PubMed ID6480520
Method "The object of the work to be described is a quantitative analysis of the mechanical properties of the hair bundles. The approach has been to measure the bending of a single bundle in the turtle cochlea by attaching it to a flexible glass fibre, and monitoring the fibre's motion through its shadowing of a light beam falling on a photodiode array."
Comments "[Researchers'] stiffness values are roughly comparable to those measured in hair cells of the frog saccule with an identical technique (mean=0.132 pN/nm: primary source Ashmore), and in cells of the guinea-pig cochlea (0.72 pN/nm mean of values for the apical turn, primary source Strelioff & Flock). For both preparations, the bundle heights are similar to those in the turtle. On the basis of [researchers'] average stiffness value, the bundle has a rotational stiffness (eqn. (4)[K(h)=KR/h^2]) of 2.2x10^-14Nxm/rad."
Entered by Uri M
ID 111041