Development of the inner ear

The adult inner ear is a very small, yet highly complex structure. In contrast, the early embryonic ear is remarkably simpler. This article focuses primarily on the development of mammalian cochlear structures, particularly the mouse cochlea, as it is a frequently studied animal model. The article gives an overview of the primary developmental events that take place from the formation of the inner ear at the otocyst stage, through differentiation of sensory structures. It begins with discussing the gross cochlear structure and further describes the development of inner ear neurons and neural innervation patterns. Following this, it explains the onset of hearing. The onset of hearing in any species is dependent on maturation of all regions of the external, middle, and inner ears, as well as the central auditory pathways. Finally, the article deals with the process of maturation of hair cell function.