Organ of Corti

The organ of Corti, or spiral organ, is the receptor organ for hearing and is located in the mammalian cochlea. This highly varied strip of epithelial cells allows for transduction of auditory signals into nerve impulses' action potential. Transduction occurs through vibrations of structures in the inner ear causing displacement of cochlear fluid and movement of hair cells at the organ of Corti to produce electrochemical signals.The organ of Corti is located in the scala media of the cochlea of the inner ear between the vestibular duct and the tympanic duct and is composed of mechanosensory cells, known as hair cells. Strategically positioned on the basilar membrane of the organ of Corti are three rows of outer hair cells (OHCs) and one row of inner hair cells (IHCs). Separating these hair cells are supporting cells: Deiters cells, also called phalangeal cells, which separate and support both the OHCs and the IHCs.The function of the organ of Corti is to transduce auditory signals and minimise the hair cells’ extraction of sound energy. It is the auricle and middle ear that act as mechanical transformers and amplifiers so that the sound waves end up with amplitudes 22 times greater than when they entered the ear.The organ of Corti, in between the scala tympani and the scala media, develops after the formation and growth of the cochlear duct. The inner and outer hair cells then differentiate into their appropriate positions and are followed by the organization of the supporting cells. The topology of the supporting cells lends itself to the actual mechanical properties that are needed for the highly specialized sound-induced movements within the organ of Corti.The organ of Corti can be damaged by excessive sound levels, leading to noise-induced impairment.Transverse section of the cochlear duct of a fetal cat.Diagrammatic longitudinal section of the cochlea.Floor of ductus cochlearis.Limbus laminæ spiralis and membrana basilaris.Section through the spiral organ of Corti. Magnified.History. (n.d.).