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  • 1
    Electronic Resource
    Electronic Resource
    The role of the pineal organ in the control of phototaxis and body coloration in rainbow trout (Salmo gairdneri, Richardson) (1970)
    Springer
    Journal of comparative physiology 68 (1970), S. 403-416 
    Details
    ISSN: 1432-1351
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. Quantitative analyses were made of the responses of normal unoperated, sham-pinealectomized (pineal intact), pinealectomized, blinded (lateral eyes removed) and blinded + pinealectomized rainbow trout (Salmo gairdneri, Richardson) on white and black backgrounds and with controlled illumination and photoperiod. 2. Phototaxis of the individual trout was tested by means of experimental choices between lighted and dark halves of an experimental tank. It was found that individual pretest departures from random 50∶50 distribution necessitated correction factors for accurate appraisal of phototaxis. Although blinding (either with or without pinealectomy) reduced the normally negative phototaxis of the trout, pinealectomy (either with or without blinding) had no detectable effect on phototaxis, at least under the experimental conditions studied. 3. Body coloration lightens at night in trout on a black background. Removal of the lateral eyes led to a reduction of this day-night difference in trout on a black background and to the presence of similar day-night coloration changes on white and black backgrounds. Pinealectomy alone had no detectable effect, but when combined with blinding, abolished the day-night difference in the blinded fish. 4. It was concluded that by either or both its photosensory and endocrine capacities the trout pineal can have a contributory role in the mediation of responses to changes in environmental illumination.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00297738
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  • 2
    Electronic Resource
    Electronic Resource
    Autoradiographic localization of 3H-5-HTP and 3H-5-HT in the pineal organ and circumventricular areas in the rainbow trout, Salmo gairdneri Richardson (1976)
    Springer
    Cell & tissue research 170 (1976), S. 61-76 
    Details
    ISSN: 1432-0878
    Keywords: Pineal organ, Salmo gairdneri ; Circumventricular ependyma ; 3H-5-HTP, 3H-5-HT ; Nuclei recessus lateralis and praeopticus ; Cerebro spinal fluid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The time course of incorporation and cellular localization of 3H-5-hydroxytryptophan (3H-5-HTP) and 3H-5-hydroxytryptamine (3H-5-HT) in the pineal and some brain regions in rainbow trout, Salmo gairdneri, were studied by quantitative and qualitative autoradiography. Among the tissues examined, the pineal shows the highest and most rapid uptake of the two isotopes. Maximum incorporation of 3H-5-HTP is achieved by 2 h and that of 3H-5-HT by 20 minutes post injection. At the end of the six-hour experimental period, a significantly high amount of radioactivity is still detectable in the pineal. The results indicate a much slower turnover of the two indoles, especially 5-HTP, in the trout than is known for mammalian tissues. Both the ependymal supporting cells and the receptor cells of the pineal localize these isotopes. In contrast, the intrapineal neurons remain unlabeled. This is taken to suggest lack of capacity of these cells to metabolize 5-HTP and 5-HT. In the circumventricular regions, the two indoles occur in the ependyma of the recessus lateralis and the recessus praeopticus. The label is also localized in the neuropil and the neurons of the nuclei recessus lateralis and praeopticus. Semiquantitative estimates reveal a significant labeling of these areas only 20 minutes after injection, although a weak but inconsistent labeling of the ependyma is evident at 5 minutes. The significance of these results is discussed in regard to (a) normal capacity of circumventricular areas to metabolize indoles and (b) a possible chemical interaction between the pineal and the brain involving a direct pineal-cerebrospinal fluid pathway.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220110
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  • 3
    Electronic Resource
    Electronic Resource
    Microangioarchitecture of the islets of Langerhans in the snakes,Naja naja, Vipera russelli, andEchis carinatus (1991)
    Springer
    Cell & tissue research 266 (1991), S. 83-88 
    Details
    ISSN: 1432-0878
    Keywords: Islets of Langerhans ; Microangioarchitecture ; Corrosion casts ; Scanning electron microscopy ; Naja naja, Vipera russelli, Echis carinatus (Serpentes)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Due to a decided lack in the literature of reports on the microangioarchitecture of the pancreas of snakes, an analysis was performed in three different species of two different ophidian families with the use of cast preparations and complementary scanning electron microscopy. The vascular architecture reflects the lobular substructure of the pancreas; the organ is supplied by branches of the superior mesentric artery. Coiled lobular arteries and arterioles continue into a meshwork of capillaries. Dilated capillaries of the endocrine portion of the pancreas are an integral component of this fine capillary network. A few very small capillaries establish a connection between the endocrine and the exocrine pancreas. The other capillaries drain into venules, which ultimately join their respective veins. No interspecific differences were noted in the vascularization of the pancreas of the three ophidian species examined. The present results suggest the existence of arterio-venous anastomoses and speak against the presence of a portal system, but establish a feed-forward capillary connection from the endocrine to the exocrine component of the ophidian pancreas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00678714
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  • 4
    Electronic Resource
    Electronic Resource
    Light and electron microscopic study on the pineal complex of the coelacanth, Latimeria chalumnae Smith (1977)
    Springer
    Cell & tissue research 178 (1977), S. 249-265 
    Details
    ISSN: 1432-0878
    Keywords: Pineal complex ; Latimeria ; Photoreceptors ; Supporting cells ; Neuropil-like areas
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pineal complex of the coelacanth, Latimeria chalumnae was studied light and electron microscopically. It consists of two vesicles representing parapineal and pineal organs. Both occur intracranially and openly communicate with each other and the brain ventricle. The entire complex shows a striking photoreceptor morphology with sensory, ependymal and nerve cells. The last cell type is more abundant in the parapineal vesicle than in the pineal organ. The following ultrastructural details of the parapineal are noteworthy: 1. The sensory cells possess large inner and outer segments protruding freely in the vesicular cavity. The outer segments measure 8–10 μm in length and consist of as many as 275 lamellae. The basal processes of these cells terminate in neuropil-like regions. Occasionally, dense granules (500–1000 Å) of uncertain identity occur in the perinuclear and inner segment cytoplasm of the cells. 2. The supporting cells are of the ependymal type. Their cytoplasm contains a filamentous feltwork and pinocytotic vesicles, but lacks secretory granules. Cytosomes are particularly abundant in cell processes in the neuropil-like zones. The basal end-feet of these cells isolate the receptor and nerve cells from the perivascular space. 3. In the neuropil-like regions, terminals of sensory cells make synaptic contacts with neuronal dendrites. Synaptic ribbon-like profiles in the terminals characterize the contact zones. Only unmyelinated nerve fibers could be observed in the small area of the tissue examined. The results are discussed with regard to photoreceptive and secretory functions of the pineal complex and its evolution in lower vertebrates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219052
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  • 5
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    Microangioarchitecture of the islets of Langerhans in the snakes,Naja naja, Vipera russelli, andEchis carinatus (1991)
    Springer
    Details
    Publication Date: 1991-10-01
    Print ISSN: 0302-766X
    Electronic ISSN: 1432-0878
    Topics: Biology , Medicine
    Published by Springer
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  • 6
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    Effect of voltage and spray–off distance of electric-arc spray technique on surface properties of nickel–chrome (Ni–Cr) coating developed on 304L stainless steel (2020)
    Institute of Physics
    Details
    Publication Date: 2020-01-07
    Electronic ISSN: 2053-1591
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Published by Institute of Physics
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