| 1. |
- Elofsson, Rolf
(författare)
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5-HT-like immunoreactivity in the central nervous system of the crayfish Pacifastacus leniusculus
- 1983
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Ingår i: Cell and Tissue Research. - 1432-0878. ; 232, s. 221-236
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Tidskriftsartikel (refereegranskat)abstract
- An immunocytochemical technique with the use of three different antibodies raised against serotonin was applied to localize the immunoreactive neurons in the central nervous system of the crayfish, Pacifastacus leniusculus. Immunoreactive neurons were found in three optic ganglia (medulla externa, interna and terminalis). They appeared in three layers of the medulla externa and interna. The medulla terminalis displayed three prominent groups of immunoreactive perikarya and mainly marginal immunoreactive fibres. Immunoreactive areas of the brain comprised the protocerebral bridge, central body, paracentral lobes and two loci in the anterior portion of the protocerebrum, i.e., the terminal areas for immunoreactive fibres from the optic centres. The olfactory lobes showed a specific immunoreactive pattern. In addition, diffusely and sparsely distributed immunoreactive fibres were found throughout the brain. The immunoreactive neurons are largely localized in the same areas of the central nervous system as the catecholaminergic neurons although some distinct differences occur.
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| 2. |
- Elofsson, Rolf, et al.
(författare)
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Gland cells in the tentacles of the jellyfish Cyanea lamarcki reactive with an antibody against 5-hydroxytryptamine.
- 1989
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Ingår i: Cell and Tissue Research. - 1432-0878. ; 255, s. 419-422
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Tidskriftsartikel (refereegranskat)abstract
- A light- and electron-microscopic immunocytochemical study on the localization of 5-hydroxytryptamine in Cyanea lamarcki revealed a reaction product in the epidermal gland cells surrounding the nematocyst clusters. The closely related scyphozoan medusa Cyanea capillata lacked a reaction product in the similar mucus-producing gland cells. Earlier conflicting views on the presence and localization of 5-hydroxytryptamine in coelenterates can thus be due to large species differences. It can be stated that 5-hydroxytryptamine is lacking in the venom of Cyanea.
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| 3. |
- Nilsson, Dan-E, et al.
(författare)
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The compound eye of Leptodora kindtii (Cladocera): : An adaptation to planctonic life.
- 1983
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Ingår i: Cell and Tissue Research. - 1432-0878. ; 230, s. 40-410
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Tidskriftsartikel (refereegranskat)abstract
- Each of the approximately 500 ommatidia in the compound eye of the cladoceran crustacean Leptodora kindtii has a crystalline cone consisting of five cells. Five retinula cells are also present, one of which contributes to the distal 1–2 μm of the rhabdom only; the other four retinula cells form a continuous rhabdom. Throughout the rhabdom its cross section displays two separate halves with the axis of the microvilli in one half perpendicular to that in the other (orthogonal pattern). Interferometric analysis of the refractive index of the crystalline cone revealed an inhomogeneous system with one distal and one proximal gradient. The gradient system was found to exclude rays entering from adjacent facets, thus maintaining the optical isolation. Consequently, these optics replace distal screening pigment, which is absent in the eye. The long and unscreened crystalline cones give rise to an almost transparent eye in conformity with the overall transparency of this planktonic animal.The morphological characteristics of the eye of this species deviate from other cladoceran eyes, but the optical design closely resembles that of some pelagic marine amphipod crustaceans.
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| 4. |
- Nilsson, Dan-E, et al.
(författare)
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The ontogenic development of refracting superposition eyes in crustaceans: transformation of optical design
- 1986
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Ingår i: Cell and Tissue Research. - : Elsevier BV. - 1432-0878. ; 18, s. 509-519
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated, comparatively, the ontogenetic development of the compound eye in larvae of a mysid (Neomysis) and a euphausiid (Thysanoessa) species and found it to be close to identical in the two species. The larval eye is of apposition type with special adaptations for planktonic life. The elongated dioptric apparatus is devoid of screening pigment and instead has a proximal lens optically isolating the ommatidium. The pigmented retina is extremely compressed making the eye largely transparent and presumably suitable for a planktonic life. The presence of this specialized type of eye in the planktonic larvae of euphausiids was known before but it is intriguing to find exactly the same type in mysids, spending their entire larval life as embryos in the female marsupium. A possible explanation is offered if mysids earlier in evolution had planktonic larvae. Upon reduction of free-living larvae, the transparent type of eye may have been preserved because there is no selection pressure on the larva to change it. In late larval life, both species transform their eyes to a refracting superposition type typical for adult mysids and euphausiids. The process of transformation and the functional connection between transparent apposition and superposition is described.
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| 5. |
- Odselius, Rolf, et al.
(författare)
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The basement membrane of the insect and crustacean compound eye: definition, fine structure and comparative morphology
- 1981
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Ingår i: Cell and Tissue Research. - 1432-0878. ; 216, s. 201-214
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Tidskriftsartikel (refereegranskat)abstract
- The basement membrane of the compound eye of four insect species and three crustacean species was investigated employing electron microscopy. The basement membrane consists of an extracellular (basal lamina) and a cellular portion, the latter being composed of the flattened terminal extensions of cone cells and accessory pigment cells in insects and distal pigment cells in crustaceans. Other cells can also contribute to the basement membrane. It is thus a complex structure in all well-developed compound eyes. The cellular contributions vary in different species and were found to correlate to specific taxonomic units.
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| 6. |
- Warfvinge, Karin, et al.
(författare)
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Single modified cilia displayed by cells of human internal stratifed epithelia (oral cavity, vagina)
- 1988
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Ingår i: Cell and Tissue Research. - 1432-0878. ; 251, s. 237-241
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Tidskriftsartikel (refereegranskat)abstract
- Serial sections of human vaginal and keratinized oral-gingival epithelia were investigated for ciliary structures. Most melanocytes of the gingival epithelium lacked cilia, whereas almost all basal keratinocytes of the deeper portion of the epithelial ridges possessed one cilium each. In the suprabasal layers of the ridges only a few keratinocytes exhibited a single cilium. In the basal layer, at the top of the connective tissue papillae, approximately every second keratinocyte displayed a single cilium. In the suprabasal layers above the ridges no ciliated keratinocytes were observed. The basal cells of the vaginal epithelium were endowed with cilia, while cilia were absent from the suprabasal cells. In the human forearm epidermis most melanocytes and keratinocytes are supplied with a single cilium; it has been suggested that they may play a role in light reception. However, the widespread occurrence of 9 + 0 cilia in epithelial cells of internal epithelia and their coincidence with the sites of renewal of keratinocytes suggests that a relationship may exist between solitary cilia and mitotic activity.
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