Scanning electron microscopy of the third ventricular floor of the rat

摘要

AbstractBy utilizing a horizontal dissection technique the entire floor of the third ventricle has been examined. When viewedin totothe ventricular floor was seen to have an hourglass shape with the supraoptic and infundibular recesses equalling the widened portions. Consistent regional differences were also noted. The rostral half of the floor was densely ciliated while the caudal portion, containing ependymal elements of the underlying median eminence, possessed few cilia. The ciliated cells ended in an abrupt transition zone located about halfway along the floor. The rostral portion of the infundibular recess had many more apical blebs and microvilli than did the caudal areas. Supraependymal cells of both the phagocyte‐like and neuron‐like variety were observed in all of the animals examined. In some animals, complex, branching, interconnecting networks of fine calibered fibers interconnected neuron‐like cells that occurred singly and occasionally in clusters. Female rats examined at all phases of the estrus cycle demonstrated no cyclic alterations of the ependymal su