Evolution of the cochlea of the ear, consisting of the scala media, the scala tympani, and the scala vestibuli. Regarding mammals, placental and marsupial cochleae have similar cochlear responses to auditory stimulation as well as DC resting potentials. This leads to the investigation of the relationship between these therian mammals and researching their ancestral species to trace the origin of the cochlea. This spiral-shaped cochlea that is in both marsupial and placental mammals is traced back to approximately 120 million years ago. The development of the most basic basilar papilla (the auditory organ that later evolved into the Organ of Corti in mammals) happened
Cochlea ions back to the endolymph after mechanotransduction in hair cells. Importantly, gap junction channels are found between cochlear supporting cells, but not auditory hair cells. In 2009, engineers at the Massachusetts Institute of Technology created an electronic chip that can quickly analyze a very large range of radio frequencies while using only a fraction of the power needed for existing technologies; its design specifically mimics a cochlea. The coiled form of cochlea is unique to mammals. In birds and in other non-mammalian vertebrates, the compartment containing the sensory cells for hearing is occasionally also called "cochlea," despite not being coiled