SCANNING ELECTRON MICROSCOPIC STUDY OF THE SENSORY HAIRS OF THE ORGAN OF CORTI USING TRANSTYMPANIC INFUSION OF FLUIDS WITH DIFFERENT OSMOTIC PRESSURE

Abstract

Morphological examination of the sensory hairs of the lower half of the 2nd turn of the organ of Corti of the guinea pig after transtympanic infusion of the aseptic fluids with different osmotic pressure was performed using a scanning electron microscope. Group A fluids (0-315 mosmol/l) did not have any injurious effect on the sensory hairs of the OHCs (outer hair cells) or IHCs (inner hair cells). In contrast, Group B fluids (720, 743 mosmol/l) appeared to cause disarrangement of the stereocilia of the OHCs. Alterations were found to be more extensive and severe in the 3rd row of OHCs. Group C fluids (1224, 1248 mosmol/l) induced total loss of sensory hairs in the 3rd and 2nd row of OHC. The remaining stereocilia in the 1st and 2nd rows showed coalescence of adjacent stereocilia. Based on these findings, the authors concluded that there is a close relationship between osmotic induction/deduction by transtympanic infusion of fluids and high osmotic pressure on the hairs of the organ of Corti.