JMA Journal

Figure 1. Primate phylogenetic tree. The common marmoset of New World monkeys is more closely related to humans than to rodents, followed by Old World monkeys.

Figure 2. Histology of the newborn cochlea of the common marmoset. The newborn cochlea of the common marmoset has 2 and a half turns, the same as the adult cochlear (A). Immunohistochemical analysis can be applied to this primate cochlea. One row of inner hair cells and 3 rows of outer hair cells can be clearly observed (B and C). IHC: inner hair cells, MYO7A: hair cell markers; OHC: outer hair cells; SOX2: supporting cell markers.

Figure 3. Developmental, morphological changes of the cochlea of the common marmoset. During the cochlear development, the cochlear duct changes its morphology. Previous studies on developmental investigation in primate cochlea have described their general time course. The common marmoset has become a novel developmental study model animal in this field. OC: organ of Corti, StV: stria vascularis.

Figure 4. Usefulness of the common marmoset in hearing research. The common marmoset is a promising new animal model in the fields of otology and audiology. Common marmosets may be useful in studies of hearing loss and aging, as well as in studies of genetic hearing loss and developmental biology.