ULTRASTRUCTURE AND FUNCTION IN NEUROHYPOPHYSIS OF THE TOAD1

作者：H. M. Gerschenfeld, Juan H. Tramezzani, Eduardo D. P. De Robertis · 发表于：Endocrinology · 年份：1960 · DOI：10.1210/endo-66-5-741 · 被引用次数：234 · 研究领域：Neurobiology and Insect Physiology Research、Adipose Tissue and Metabolism、Neuroscience of respiration and sleep

An electron microscope study was carried out on hypothalamic portions of the preoptic-neurohypophyseal tract and in the infundibular process of toads in normal water balance or treated experimentally to produce release of the posterior pituitary hormones. Axons containing neurosecretory granules have been observed in the hypothalamus (region I) in the hilum of the infundibular process (region II), near the capillaries (region III) and at the ending proper (region IV). The neurosecretory granules, that are formed within special dense vesicles, have a high electron density and are surrounded by an enveloping membrane. Their size increases from 620 Å in region I to 1350 Å-1500 Å in regions II and III. At the ending (region IV) a second component appears which is similar to the synaptic vesicles described by De Robertis and Bennett (1954). The mean size, of the vesicles is of 420 Å and the histograms show no overlapping between these components. A and the histograms show no overlapping between these components. Within the axons of region I to III neuroprotofibrils and finer neurofilaments arc observed. In all parts of the axons there arc bizarrely shaped mitochondria that bear no relationship to the neurosecretory material. In chronically dehydrated animals the neurosecretory granules disappear from the endings but persist in other regions of the axon. At the endings the synaptic vesicles remain and appear to increase in number after chronic dehydration. In acutely dehydrated ani...