Acid phosphatase activity in the chick's inner ear.

The cellular localization of distribution of acid phosphatase (AP) in the plastic sections of newly hatched chick's inner ear were investigated utilizing an azo-coupling method. AP activity as evidenced by azo dye deposits were well defined and localized in various cells of membranous labyrinth. Intense AP activity was detectable in the supranuclear area of hair cells in the basilar papilla and vestibular sensory hair cells. As in the case of the other sites of AP activity, marked AP activity was seen in the supranuclear area of the transitional epithelia of crista ampullaris and in the supranuclear area, or diffusely in the cytoplasm of the dark cells at the base of crista ampullaris. The columnar cells and the cells of tegmentum vasculosum showed moderate to strong AP activity. The statoacoustic and vestibular ganglion cells showed various degrees of AP activity. On the AP activity of statoacoustic or vestibular ganglion, in comparison between the sections from JB-4 Plus embedded specimens and those from LR White embedded specimen, the latter could more intensely demonstrate AP activity than the former. Moreover, sections fixed in 2.5% paraformaldehyde demonstrated more intense AP activity than those fixed in 2.5% glutaraldehyde.