Changes in subcellular structures of arcuate neurons correlated in a consistent way with stages of the estrous cycle of the rat. Associated with the rough endoplasmic reticulum short ribbons of moderately electron dense material appeared at metestrus and circular or elliptical bodies termed “ribbon-rolls” at diestrus and proestrus. Although present in proestrus, the ribbon-rolls were smaller at this stage. In a few neurons in diestrous females and in ovariectomized animals one to seven months before perfusion multiple large ribbon-rolls occupied much of the cytoplasm. Also, frequency of dense granules and lysosomes increased in diestrus. The significance of the ribbon-rolls and changes in other structures during the estrous cycle are discus
展开▼
