| 1. |
- Ekström, P., et al.
(författare)
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Ontogenetic development of the pineal organ, parapineal organ, and retina of the three-spined stickleback, Gasterosteus aculeatus L. (Teleostei) - Development of photoreceptors
- 1983
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Ingår i: Cell and Tissue Research. - 0302-766X. ; 233:3, s. 593-609
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Tidskriftsartikel (refereegranskat)abstract
- The ontogenetic developments of the pineal organ, parapineal organ, and retina were studied by the use of light and electron microscopy in embryos and fry of the teleost, Gasterosteus aculeatus, from 60 to 168 h after fertilization. Sixty to 66 h after fertilization, the primordium of the pineal complex is discernible in the diencephalic roofplate; the parapineal anlage is located rostral to the pineal anlage. Photoreceptor cells endowed with outer segments are present in the embryonic pineal organ already after 72 h, whereas outer segments of retinal photoreceptors could not be demonstrated before 144 h (hatching occurs between 120-144 h). Furthermore, neuropil formations with synaptic specializations are present in the rostral part of the pineal organ 108 h after fertilization. At 72 h, the embryonic parapineal parenchyma is already differentiated into parapinealocytes, which give rise to the parapineal tract, and glia-resembling elements. Although parapinealocytes carry cilia (9 × 2 + 0), only a single outer segment of the photoreceptor type could be demonstrated in the parapineal organ of one adult stickleback. Photoreceptors present in the pineal organ of unhatched embryos are hardly involved in visual functions, but may already at this early developmental stage serve as photoneuroendocrine transducers.
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| 2. |
- Ekström, Peter
(författare)
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Retinofugal projections in the eel, Anguilla anguilla L. (Teleostei), visualized by the cobalt-filling technique
- 1982
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Ingår i: Cell and Tissue Research. - 0302-766X. ; 225:3, s. 507-524
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Tidskriftsartikel (refereegranskat)abstract
- The retinofugal projections in the eel were studied by use of the cobalt-filling technique. The optic tract projects contralaterally to the hypothalamic optic nucleus, the anterior periventricular nucleus, the lateral geniculate nucleus, the dorsomedial optic nucleus, four pretectal recipient areas, the optic tectum, and the tegmentum. Small ipsilateral projections were demonstrated in the hypothalamic optic nucleus, the dorsomedial optic nucleus, and the optic tectum.
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| 3. |
- Kannisto, P, et al.
(författare)
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Intraovarian adrenergic nerves in the guinea-pig : development from fetal life to sexual maturity
- 1984
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Ingår i: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 0302-766X .- 1432-0878. ; 238:2, s. 40-235
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Tidskriftsartikel (refereegranskat)abstract
- The development of the intraovarian adrenergic nervous system was investigated in the guinea-pig by use of chemical determination of catecholamines with high performance liquid chromatography (HPLC) and with the formaldehyde-induced fluorescence method for visualization of adrenergic nerves (Falck-Hillarp technique). Ovaries from fetuses (39-40, 45-50, 55-57, 60-63 days of gestation) and young animals (1, 2, 3, 7, 14, 30, 40-45 days of age) were included in the study. The noradrenaline concentration was low in the ovaries from the youngest fetuses but increased with age, reaching a maximum level at 2 days post partum. A marked decrease in noradrenaline concentration from the second to the third day of life was found as a consequence of the rapid increase in the ovarian weight during this time. A similar decrease in ovarian noradrenaline concentration after a period of rapid ovarian growth was noted at 30 days of age. Measurable amounts of adrenaline were found in the ovary only in the fetal stages; the highest concentration (0.73 microgram) was detected at 55-57 days of gestation.
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| 4. |
- Tågerud, Sven, et al.
(författare)
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Lysosomes in skeletal muscle following denervation. Time course of horseradish peroxidase uptake and increase of lysosomal enzymes
- 1984
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Ingår i: Cell and Tissue Research. - 0302-766X .- 1432-0878. ; 236:1, s. 73-79
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Tidskriftsartikel (refereegranskat)abstract
- The in-vivo uptake of exogenously applied horseradishperoxidase and the activities of the lysosomal enzymesacid phosphatase and cathepsin D were studied histochemicallyand/or biochemically in innervated and2-14 day-denervated tibialis anterior muscles of the mouse.The biochemically determined uptake of horseradish peroxidaseshowed a large increase already 4 days after denervation.The activities of the lysosomal enzymes increased ina more gradual fashion, and only cathepsin D showed anincrease in activity when expressed as total activity per muscle.Histochemically horseradish peroxidase was found tobe localized in muscle fibres in characteristic spindle-shapedsegments after denervation. The main increase in thenumber of such segments per transverse section of the muscleoccurred between 3 and 6 days after denervation. Inserial sections these segments frequently showed positivestaining also for acid phosphatase.It is concluded that exogenously applied horseradishperoxidase is taken up into the lysosomal system, whichafter denervation becomes organized into characteristicspindle-shaped segments in the muscle fibres. The endocyticactivity of muscle fibres increases early after denervation.This is followed by a more gradual increase in activity oflysosomal enzymes and finally by an organization of thelysosomal system into characteristic spindle-shaped segments.The results are compatible with the working hypothesisthat increased endocytosis may initiate lysosomal activationin denervated skeletal muscle.
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| 5. |
- van Veen, Theo, et al.
(författare)
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Serotonin and opsin immunoreactivities in the developing pineal organ of the three-spined stickleback, Gasterosteus aculeatus L.
- 1984
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Ingår i: Cell and Tissue Research. - 0302-766X. ; 237:3, s. 559-564
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Tidskriftsartikel (refereegranskat)abstract
- 5-hydroxytryptamine (5-HT, serotonin)- and opsin-immunoreactive sites were studied in the developing pineal complex of the stickleback, Gasterosteus aculeatus L., by use of light-microscopic indirect immunoperoxidase techniques. 5-HT immunoreactivity first occurs in the pineal organ at the age of 80 h after fertilization and appears to be localized in cells of the photoreceptor type. The outer segments of a few pineal photosensory cells exhibit opsin immunoreactivity at the age of 84 h after fertilization. The number of cells seems to increase until the pineal organ is completely developed. The increase in the number of 5-HT immunoreactive perikarya runs parallel in time to that of the opsinimmunoreactive outer segments. The cells of the parapineal organ show neither opsin nor 5-HT immunoreactivity. The retina of the embryonic stickleback does not display opsin immunoreactivity until after hatching, which takes place about 144 h after fertilization. These results suggest, in the three-spined stickleback, an earlier light-perception capacity for the developing pineal organ than for the retina.
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| 6. |
- van Veen, Th., et al.
(författare)
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The pineal complex of the three-spined stickleback, Gasterosteus aculeatus L. - A light-, electron microscopic and fluorescence histochemical investigation
- 1980
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Ingår i: Cell and Tissue Research. - 0302-766X. ; 209:1, s. 11-28
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Tidskriftsartikel (refereegranskat)abstract
- The pineal complex of the three-spined stickleback (Gasterosteus aculeatus L.) was investigated by light and electron microscopy, as well as fluorescence histochemistry for demonstration of catecholamines and indolamines. The pineal complex of the stickleback consists of a pineal organ and a small parapineal organ situated on the left side of the pineal stalk. The pineal organ, including the entire stalk, is comprised mainly of ependymal-type interstitial cells and photoreceptor cells with well-developed outer segments. Both unmyelinated and myelinated nerve fibres are present in the pineal organ. Nerve tracts from the stalk enter the habenular and posterior commissures. A small bundle of nerve fibres connects the parapineal organ and the left habenular body. The presence of indolamines (5-HTP, 5-HT) was demonstrated in cell bodies of both the pineal body and the pineal stalk, and catecholaminergic nerve fibres surround the pineal complex.
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