Quantitative studies on the nervus stapedius of the mouse with the electron microscope.

A nerve fiber count analysis was performed with the electron microscope on the nerve to the stapedius in seven mice. On an average, 77 (81%) of the total nerve fibers (95) were myelinated and 18 (19%) unmyelinated. The nerve consisted mostly of large myelinated fibers, minor diameters of which measured 3-4 micrometer most frequently like the large fiber zone of the motor root of the facial nerve and the facial trunk. The nerve fibers to the stapedius come from the large fiber zone of the facial nerve trunk.