Early Embryology of the Vertebrate Ear

* Final gross prices may vary according to local VAT.

Get Access

Abstract

Organogenesis of the vertebrate inner ear has been described as “one of the most remarkable displays of precision microengineering in the vertebrate body” (Swanson, Howard, and Lewis 1990). The initial morphological event in ear development in all vertebrates is the formation of the embryonic otic placode, a thickening of the head ectoderm in the region of the developing hindbrain. Through interaction with and incorporation of tissue from several other embryonic sources, the placode develops into the otocyst or otic vesicle, a differentiated structure with sharply defined borders (Noden and Van De Water 1986; Couly, Coltey, and Le Douarin 1993). The epithelium of the otic placode/vesicle also gives rise to the primary neurons of the statoacoustic ganglion, later in development called the cochleovestibular ganglion, the octaval, or the otic ganglion (probably the most appropriate terminology), which contributes to cranial nerve VIII and to the specialized sensory structures known as hair cells (Fig. 3.1).