Abstract
13.0day rat embryos were cultured for 36 hours in the whole embryo culture system. Continuous flow of mixed gas consisting of 5%CO2 and 95%O2 were maintained in the culture bottles through the duration of culture in this series. The cultured embryos were histologically examined and compared with 13.0day embryos especially on the ear region. In 13.0day embryo, branchial archs remained and any anlage of middle ear structure was not developed yet. On the other hand, in cultured embryos, pinna and external auditory canal were developing and previous otocyst had developed to vestibular, cochlear and semicircular canal portions in shape. The tubotympanic recess extended in to the middle ear region and the stapedial anlage appeared adjacent to the developing otic capsule.
