There are many studies about development of the utricular macula using the TEM. This study demonstrates the morphological development of the utricular macula in the mouse using the SEM.
The utricular macula of CBA/CBA mouse from the 11.5th gestational day to the 2w postnatal day were studied.
Numerous microvilli and primary cilium on the surface of otocyst were found between 11.5th and 12.5th gestational day. Sensory hairs appeared on the 13.5th gestational day. Its kinocilium and stereocilia were short and the length of stereocila were almost equal in size. The polarity of kinocilium was first noticed after 16.5th gestational day. The formation of otoconia started on the 14.5th gestational day. Its shape was dumbbell-like, egg-like columnar and so on. Otoconia with hexagonal form was recognized after 16.5th gestational day.