| one publication added to basket [69075] | Het caudaal neurosecretorische systeem der Teleosteï
Bosteels, S. (1965). Het caudaal neurosecretorische systeem der Teleosteï. MSc Thesis. Katholieke Universiteit Leuven. Faculteit Wetenschappen: Leuven. 79 pp.
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| Available in | Author |
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Document type: Dissertation
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| Keywords |
Anatomical structures > Neurosecretory system
Teleostei [WoRMS]
Marine/Coastal |
| Abstract |
In 1955 ENAMI described a neurosecretory system in the spinal cord of Anguilla japonica. This was the starting-point of numerous studies concerning the morphological as well as the functional aspect of the neurosecretory system.The function of the urophysis was connected with osmoregulation and with gas metabolism in the air bladder. ENAMI supposed it to play a part in the osmoregulation because in this system osmotic stimuli cause a discharge of neurosecretion. This is confirmed by ROY (1962).TAKASUGI and BERN (1962) however perceived an inconsistent answer to osmotic stimuli and SANO (1961) was not able to notice important changes. Nevertheless the connexion of the system with osmoregulation is generally accepted. Extirpation of the organ decreases the osmoregulatary adaptation capacity of various test objects (ENAMI et al, 1956; HOLMGREN, 1958; TAKASUGI and BERN, 1962). How the urophysis interferes in this process is not known. Experiments by MAETZ et al. (1963) on Carassius auratus point to an influence of urophyseal extracts on the gill and on the kidney. These effects resemble very much the action of neurohypophyseal extracts. The urophyseal extract, however, does not contain neurohypophyseal peptides (SAWYER and BERN, 1963).According To ROY (1962) a CRF (corticotrophin releasing factor) is present in the urophyseal extracts. This makes clear that the function of the urophysis should be regarded as one of the endocrine glands that influence the osmoregulation. That is why in the survey of literature the function of other endocrine glands that are connected with osmoregulation is illustrated as well.The morphology of the neurosecretory system is dealt with on the basis of the investigation of four specimens, namely Salmo sa1ar, Salmo trutta, Anguilla anguilla and Zoarces viviparus. These species give a picture of the various forms the caudal neurosecretory system can assume with teleosteï.The neurosecretory activity was studied more in special on Salmo salar. We examined whether specimens living in different osmotic situations showed different activities. The difference perceived is compared with the results various authors described. Whether this can be connected with the function premised was discussed before. |
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