During a one-year period, seasonal histological changes of the caudal neurosecretory system in Ictalurus sp. and its early differentiation during post-embryonic development, were examined. In the first month of life there are only few details indicating the first differentiation of caudal neurosecretory system. In the second month, the anterior Dahlgren cells appear identificable by their size. In the next month the number of Dahlgren cells increases, and the organisation of a functional system is established. After careful examination of several adult specimen, it resulted that no significant seasonal changes either in the number of neurosecretory cells, or in the amount of the neurosecretory material are detectable.
Referenze Bibliografiche
[1] U. DAHLGREN, On the electric motor nerve centers in the skates (Rajidae), «Science», 40, 862-863 (1914).
[2] C. C. SPEIDEL, Gland-cells of internal secretion, in the spinal cord of the skates, «Carnegie Inst. Wash. Publ.», 281, 1-31 (1919).
[3] G. FAVARO, Di una formazione annessa alla midolla spinale caudale dei Teleostei, «Resoc. R. Accad. Pelor.», 8, 56-57 (1923).
[4] M. ENAMI, Studies in neurosecretion II: Caudal neurosecretory system in the eel (Anguilla japonica), «Gumma J. Med. Sci.», 4, 23-36 (1955).
[5] A. PEYROT, Il sistema neurosecernente caudale degli Ittiopsidi, osservazioni sulla lampreda di ruscello (Lampetra zanandreai), «Boll. Soc. It. Biol. Sper.», 40, 207-210 (1964).
[6] G. FRIDBERG, The caudal neurosecretory system in some elasmobranchs, «Gen. Comp. Endocrinol.», 2, 249-265 (1962).
[7] M. ENAMI, Studies in neurosecretion XII. Electron microscopy of the secrete granules in the caudal neurosecretory system of the eel., «Proc. Japan Acad.», 34, 164-168 (1958).
[8] Y. HOMMA, Some evolutionary aspects of neural control of internal secretion in the Ichthyoform animals, «Proc. Jap. Soc. Systemat. Zool.», 2, 6-11 (1966).
[9] YAGI K. e BERN H. A., Electrophysiologic analysis of the response of the caudal neuro secretory system of Tilapia mossambica to osmotic manipulations, «Gen. Comp. Endocrinol.», 5, 509-526 (1965).
[10] C. C. SPEIDEL, Further comparative studies in other fishes of cells that are homologous to the large irregular glandular cells in the spinal cord of the skates, «J. Comp. Neurol.», 34, 303-317 (1922).
[11] Y. SANO e F. KAWAMOTO, Entwicklungsgeschichtliche Beobachtungen an der Neurophysis spinalis caudalis von Lebistes reticulatus, «Z. Zellforsch.», 51, 56-64 (1959).
[12] B. A. AFZELIUS e G. FRIDBERG, The fine structure of the caudal neurosecretory system in Raja batis, «Z. Zellforsch», 59, 289-308 (1963).
[13] L. RAUNICH, C. CALLEGARINI e G. CAVICCHIOLI, Polimorfismo emoglobinico e caratteri sistematici del genere Ictalurus dell'Italia settentrionale, «Arch. Zool. Ital.», 51, 498-510 (1966).
[14] P. B. ARMSTRONG, Stages in the development of Ictalurus nebulosus, Syracuse University Press (1962).
Con il contributo del Ministero per i Beni e le Attività Culturali