Neurosecretory and Pars-Intermedia Cells of Fish and Mammals

Since BARGMANN (1967) and SCHARRER (1969) defined neurohormones produced by neurosecretory cells, many papers have dealt with their further elucidation in different species. The study of neurosecretory cells has proceeded using contemporary methods (POLENOV, 1968; SZENTAGOTHAI et al., 1968; DIERICKX and VANDESANDE, 19 75; and many others). Current concepts of neurosecretion have been given by SCHARRER (1969). There are still many unanswered questions concerning the differentiation of neurosecretory cells, differences in the development and structure of hypothalamic nuclei in various species, interrelationships between afferents of various brain structures and neurosecretory cells, their efferent terminals in the neurohypophysis and pars intermedia, the site of biosynthesis of releasing factors (RF) and inhibiting factors (IF) and biogenic amines, etc.