Abstract: | Summary Electron microscopic investigation of neural isolated and normal pars ventralis of the tuber cinereum showed the presence, in Rana temporaria, of a tubero-hypophysial neurosecretory system. A striking structural resemblance between this parvicellular, aldehydefuchsin negative, tubero-hypophysial neurosecretory system and the magnocellular, aldehydefuchsin positive, hypothalamo-hypophysial neurosecretory system was observed. Six different neurosecretory cell types are described, characterized by different shape and size of their respective secretory granules. The nature of the secretory product of these cells is briefly discussed.Of the results of this investigation, a preliminary note has been published (Dierickx, 1971).The authors wish to thank Prof. Dr. H. Steyaert and Dr. W. Moerdijk of the Laboratory for Mathematical Statistics, Ghent University, for invaluable advice and assistance with their computers. They thank Dr. G. De Waele for his help with the scanning electron microscopy. |