Abstract and Keywords
This article reviews homology between epithelial cells of the cochlea and vestibular system emphasizes the conservation of sensory and homeostatic mechanisms. The inner ear consists of an array of interconnected fluid compartments that include the cochlea, utricle, saccule, three ampullae and semicircular canals, the endolymphatic duct, and the endolymphatic sac. The composition of the luminal fluid, the end lymph, differs between different parts of the inner ear and from the surrounding fluid, the perilymph, and from cerebrospinal fluid and plasma. The establishment and maintenance of the specialized fluid composition and voltages in the inner ear rely on complex interactions between ion channels, pumps, transporters, barrier proteins, and regulatory signal pathways. One of the great challenges facing otolaryngology is to understand inner ear homeostasis on the level of the genome, the proteome, and the physiome.