[Morphologic characteristic of substance P immunoreactivity in facial nerve of normal cats]

This paper presents the morphologic charactistic of substance P immunoreactivity (SP-IR) in the facial nerve and geniculate ganglion of normal cats by using immunohistochemical technique and immunoelectronic microscopy. SP-IR positive cells are more in geniculate ganglion than the other parts of the facial nerve. These cells are black. The sizes of their somata are different, and the shapes are round, elliptic or irregular. The somata are connected with each other by their central and peripheral synapses in the shapes of spider's web or root of a tree. Among the cells the bipolar and pseudounipolar cells are also found. SP-IR positive fibers curve and some of them have obvious expansive bodies, which are beaded, different in diameter. Under electronic microscope SP-IR positive cells show thicker electronic density than the others, and SP-IR positive products with thick electronic density are found in the nuclei, nucleomembranes, outer membranes of mitochndria and plasma. The nerve fibers are myelinated and the myelin sheath is concentric, and in the axoplasms there are nervous microfilament and a bit of mitochndria.