| 1. |
- Audehm, Uwe, et al.
(författare)
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Patterns and projections of crustacean cardioactive-peptide-immunoreactive neurons of the terminal ganglion of crayfish.
- 1993
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Ingår i: Cell and Tissue Research. - : Springer. - 0302-766X .- 1432-0878. ; 272:3, s. 473-485
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Tidskriftsartikel (refereegranskat)abstract
- Three distinct clusters of crustacean cardioactive-peptide-immunoreactive neurones occur in the terminal abdominal ganglion of the crayfish species Orconectes limosus, Astacus leptodactylus, Astacus astacus and Procambarus clarkii, as revealed by immunocytochemistry of whole-mount preparations and sections. They exhibit similar topology and projection patterns in all four studied species. An anterior ventral lateral and a posterior lateral cluster contain one small, strongly stained perikaryon and two large, less intensely stained perikarya, each showing contralateral projections. A posterior medial lateral cluster of up to six cells also contains these two types of perikarya. Whereas the small type perikarya belong to putative interneurones, the large type perikarya give rise to extensive neurohaemal plexuses in perineural sheaths of the third roots of the fifth abdominal ganglia, the connectives, the dorsal telson nerves, the ganglion itself, its roots and arteriolar supply. Thin fibres from these plexuses reach newly discovered putative neurohaemal areas around the hindgut and anus via the intestinal and the anal nerves, and directly innervate the phasic telson musculature. A comparison with earlier investigations of motoneurones and segmentation indicates that these three cell groups containing putative neurosecretory neurones may be members of at least three neuromeres in this ganglion. Crustacean cardioactive peptide released from these neurones may participate in the neurohumoral and modulatory control of different neuronal and muscle targets, thereby exceeding its previously established hindgut and heart excitatory effects.
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| 2. |
- Breidbach, Olaf, et al.
(författare)
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Crustacean cardioactive peptide-immunoreactive neurons in the ventral nerve cord and the brain of the meal beetle Tenebrio molitor during postembryonic development
- 1991
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Ingår i: Cell and Tissue Research. - : Springer. - 0302-766X .- 1432-0878. ; 265:1, s. 129-144
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Tidskriftsartikel (refereegranskat)abstract
- By use of an antiserum against the crustacean cardioactive peptide (CCAP) several types of bilaterally symmetrical neurons were mapped quantitatively in the ventral nerve cord and brain of Tenebrio molitor. The general architecture of these neurons was reconstructed. From the suboesophageal to the 7th abdominal ganglia 2 types of neurons showed a repetitive organization of contralateral projection patterns in each neuromere. The first type had few branches in the central neuropil and a distinct peripheral projection. The 2nd type was characterized by an elaborate central branching pattern, which included ascending and descending processes. Some of its peripheral branches supplied peripheral neurohaemal areas. In the protocerebrum, 10 CCAP-immunoreactive neurons occurred with projections into the superior median protocerebrum and the tritocerebrum. Immunopositive neurons were mapped in larvae, pupae and adults. All types of identified neurons persisted throughout metamorphosis, maintaining their essential structural and topological characteristics. The CCAP-immunoreactive neurons of T. molitor were compared with those described for Locusta migratoria. Putative structural homologies of subsets of neurons in both species are discussed.
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| 3. |
- Dircksen, Heinrich, 1954-, et al.
(författare)
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Crustacean cardioactive peptide in the nervous system of the locust, Locusta migratoria: an immunocytochemical study on the ventral nerve cord and peripheral innervation
- 1991
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Ingår i: Cell and Tissue Research. - Heidelberg New York : Springer. - 0302-766X .- 1432-0878. ; 263, s. 439-457
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Tidskriftsartikel (refereegranskat)abstract
- Crustacean cardioactive peptide-immunoreactive neurons occur in the entire central nervous system of Locusta migratoria. The present paper focuses on mapping studies in the ventral nerve cord and on peripheral projection sites. Two types of contralaterally projecting neurons occur in all neuromers from the subesophageal to the seventh abdominal ganglia. One type forms terminals at the surface of the thoracic nerves 6 and 1, the distal perisympathetic organs, the lateral heart nerves, and on ventral and dorsal diaphragm muscles. Two large neurons in the anterior part and several neurons of a different type in the posterior part of the terminal ganglion project into the last tergal nerves. In the abdominal neuromers 1–7, two types of ipsilaterally projecting neurons occur, one of which gives rise to neurosecretory terminals in the distal perisympathetic organs, in peripheral areas of the transverse, stigmata and lateral heart nerves. Four subesophageal neurons have putative terminals in the neurilemma of the nervus corporis allati II, and in the corpora allata and cardiaca. In addition, several immunoreactive putative interneurons and other neurons were mapped in the ventral nerve cord. A new in situ whole-mount technique was essential for elucidation of the peripheral pathways and targets of the identified neurons, which suggest a role of the peptide in the control of heartbeat, abdominal ventilatory and visceral muscle activity.
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| 4. |
- Dircksen, Heinrich, 1954-
(författare)
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Fine structure of the neurohemal sinus gland of the shore crab, Carcinus maenas, and immuno-electron-microscopic identification of neurosecretory endings according to their neuropeptide contents
- 1992
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Ingår i: Cell and Tissue Research. - 0302-766X .- 1432-0878. ; 269:2, s. 249-266
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Tidskriftsartikel (refereegranskat)abstract
- The sinus gland of the shore crab, Carcinus maenas, is a compact assembly of interdigitating neurosecretory axon endings abutting upon the thin basal lamina of a central hemolymph lacuna. Four types of axon endings are distinguishable by the size distribution, shape, electron density and core structure of their neurosecretory granules. One additional type of axon ending is characterized by electron-lucent vacuoles and vesicles. The axon profiles are surrounded by astrocyte-like glial cells. Various fixations followed by epoxy- or Lowicryl-embedding were compared in order to optimize the preservation of the fine structure of the granule types and the antigenicity of their peptide hormone contents. By use of specific rabbit antisera, the crustacean hyperglycemic, molt-inhibiting, pigment-dispersing, and red-pigment-concentrating hormones were assigned to the four distinct granule types which showed no overlap of immunostaining. Epi-polarization microscopy and ultrathin section analysis of immunogold-stained Lowicryl-embedded specimens revealed that immunoreactivity to Leu-enkephalin and proctolin is co-localized with molt-inhibiting hormone immunoreactivity in the same type of granule. The size and core structure of the immunocytochemically identified granule types vary little with the different pretreatments but, in some cases, to a statistically significant extent. The present results are compared with those from earlier studies of sinus glands in different crustaceans. The methods of granule identification used in this study supplement the classical approach in granule typing; they are easier to perform and more reliable for the analysis of release phenomena in identified secretory neurons supplying the neurohemal sinus gland.
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| 5. |
- Homberg, Uwe, et al.
(författare)
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Comparative anatomy of pigment-dispersing hormone-immunoreactive neurons in the brain of orthopteroid insects
- 1991
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Ingår i: Cell and Tissue Research. - : Springer. - 0302-766X .- 1432-0878. ; 266:2, s. 343-357
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Tidskriftsartikel (refereegranskat)abstract
- In a comparative study, the anatomy of neurons immunoreactive with an antiserum against the crustacean beta-pigment-dispersing hormone was investigated in the brain of several orthopteroid insects including locusts, crickets, a cockroach, and a phasmid. In all species studied, three groups of neurons with somata in the optic lobes show pigment-dispersing hormone-like immunoreactivity. Additionally, in most species, the tritocerebrum exhibits weak immunoreactive staining originating from ascending fibers, tritocerebral cells, or neurons in the inferior protocerebrum. Two of the three cell groups in the optic lobe have somata at the dorsal and ventral posterior edge of the lamina. These neurons have dense ramifications in the lamina with processes extending into the first optic chiasma and into distal layers of the medulla. Pigment-dispersing hormone-immunoreactive neurons of the third group have somata near the anterior proximal margin of the medulla. These neurons were reconstructed in Schistocerca gregaria, Locusta migratoria, Teleogryllus commodus, Periplaneta americana, and Extatosoma tiaratum. The neurons have wide and divergent arborizations in the medulla, in the lamina, and in several regions of the midbrain, including the superior and inferior lateral protocerebrum and areas between the pedunculi and alpha-lobes of the mushroom bodies. Species-specific differences were found in this third cell group with regard to the number of immunoreactive cells, midbrain arborizations, and contralateral projections, which are especially prominent in the cockroach and virtually absent in crickets. The unusual branching patterns and the special neurochemical phenotype suggest a particular physiological role of these neurons. Their possible function as circadian pacemakers is discussed.
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| 6. |
- Honkanen, Tapio, et al.
(författare)
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Comparative study of the olfactory epithelium of the three-spined stickleback (Gasterosteus aculeatus) and the nine-spined stickleback (Pungitius pungitius)
- 1992
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Ingår i: Cell & Tissue Research. - 0302-766X. ; 269:2, s. 267-273
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Tidskriftsartikel (refereegranskat)abstract
- The olfactory epithelium of the three-spined stickleback (Gasterosteus aculeatus) and the nine-spined stickleback (Pungitius pungitius) has been studied with a conventional histochemical and a novel immunological staining technique. In both species, the sensory epithelium is arranged in folds separated by non-sensory epithelial tissue. In the nine-spined stickleback, intrinsic folds consisting of non-sensory cells are found in the apical part of the sensory epithelium where they divide the surface of the sensory epithelium into small islets. These non-sensory cells are non-ciliated, flattened and piled on top of each other; they contain numerous electron-translucent vesicles. The intrinsic folds are absent from the sensory epithelium of the three-spined stickleback. In both species, axons of receptor cells form a layer of fibers in the sensory epithelium immediately above the basal cells. In the three-spined stickleback, thick branches of the olfactory nerve are frequently found in this layer. These branches are only occasionally observed in the sensory epithelium of the nine-spined stickleback. Thus, the three-spined stickleback and the nine-spined stickleback show considerable differences in the organization of the sensory regions of the olfactory epithelium.
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| 7. |
- Johansson, Kjell
(författare)
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Identification of different types of serotonin-like immunoreactive olfactory interneurons in four infraorders of decapod crustaceans
- 1991
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Ingår i: Cell and Tissue Research. - 0302-766X .- 1432-0878. ; 264:2, s. 357-362
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Tidskriftsartikel (refereegranskat)abstract
- An antiserum raised against serotonin (5HT) was applied to the brains of representatives of four different infraorders of decapod crustaceans, and revealed two morphological classes of olfactory interneurons. They were classified by the position and size of their cell bodies, and their connection pattern. One class consisted of giant olfactory interneurons and the other of globuli cells. They were regarded as input and intrinsic interneurons, respectively, because of their morphology. The two classes displayed a similar pattern in two of the infraorders, whereas only one class appeared in the other two infraorders.
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| 8. |
- Lexell, Jan, et al.
(författare)
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Quantitative morphology of stimulation-induced damage in rabbit fast-twitch skeletal muscles
- 1992
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Ingår i: Cell and Tissue Research. - 0302-766X .- 1432-0878. ; 269:2, s. 195-204
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to examine the contention that stimulation-induced damage, resulting in degeneration with subsequent regeneration, plays a major role in the transformation of fibre type brought about by chronic electrical stimulation. Data from histological and histochemical sections of 9-day-stimulated rabbit fast-twitch muscles were analysed with multivariate statistical techniques. Fibre degeneration and regeneration varied non-systematically between sample areas at any given cross-sectional level. In the extensor digitorum longus muscle, but not in the tibialis anterior, there was more degeneration in proximal than in distal portions of the muscle. The extensor digitorum longus muscle consistently showed more degeneration than the tibialis anterior muscle. Degeneration was less extensive for an intermittent pattern of stimulation that delivered half the aggregate number of impulses of continuous stimulation. Degeneration and regeneration varied markedly between individual rabbits in each of the groups. Sections that revealed the most degeneration and regeneration also had more fibres that reacted positively with an anti-neonatal antibody. Rigorous analysis of different sources of variation has helped to explain apparent conflicts in the literature. The incidence of muscle fibre damage in the stimulated tibialis anterior muscle is low, showing that the contribution of degenerative-regenerative phenomena to fibre type conversion in this muscle is insignificant.
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| 9. |
- Lexell, Jan, et al.
(författare)
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Stimulation-induced damage in rabbit fast-twitch skeletal muscles : a quantitative morphological study of the influence of pattern and frequency
- 1993
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Ingår i: Cell and Tissue Research. - 0302-766X .- 1432-0878. ; 273:2, s. 357-362
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to determine whether muscle fibre degeneration brought about by chronic low-frequency electrical stimulation was related to the pattern and frequency of stimulation. Rabbit fast-twitch muscles, tibialis anterior and extensor digitorum longus, were stimulated for 9 days with pulse trains ranging in frequency from 1.25 Hz to 10 Hz. Histological data from these muscles were analysed with multivariate statistical techniques. At the lower stimulation frequencies there was a significantly lower incidence of degenerating muscle fibres. Fibres that reacted positively with an antineonatal antibody were most numerous in the sections that revealed the most degeneration. The dependence on frequency was generally similar for the two muscles, but the extensor digitorum longus muscles showed more degeneration than the tibialis anterior at every frequency. Muscles subjected to 10 Hz intermittent stimulation showed significantly less degeneration than muscles stimulated with 5 Hz continuously, although the aggregate number of impulses delivered was the same. The incidence of degeneration in the extensor digitorum longus muscles stimulated at 1.25 Hz was indistinguishable from that in control, unstimulated muscles; for the tibialis anterior muscles, this was also true for stimulation at 2.5 Hz. We conclude that damage is not an inevitable consequence of electrical stimulation. The influence of pattern and frequency on damage should be taken into account when devising neuromuscular stimulation regimes for clinical use
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| 10. |
- Tågerud, Sven, et al.
(författare)
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High endocytotic and lysosomal activities in segments of rat myotubes differentiated in vitro
- 1990
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Ingår i: Cell and Tissue Research. - 0302-766X .- 1432-0878. ; 259, s. 225-232
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Tidskriftsartikel (refereegranskat)abstract
- Endocytosis and the lysosome system have beenstudied in rat myotubes differentiated in vitro. Horseradishperoxidase was used as marker for endocytosis and wasfound to accumulate unevenly in the myotubes. Small segmentsof myotubes display very high endocytotic activity.Similar segments contained numerous lysosomes, as seenby the accumulation of neutral red or histochemical stainingfor acid phosphatase. The segments also contained accumulationsof acetylcholine receptors as determined by bindingof tetramethyl rhodamine-labelled c~-bungarotoxin. Unstainedsegments in living cultures could be recognized byphase-contrast microscopy since they often appeared somewhatdilated and were not as well spread on the culturesurface as the main parts of the myotubes. Ultrastructurally,the segments contained an intensely proliferating tubularsystem in communication with the extracellular space,which therefore probably represents the developing transversetubular system. The segments also contained endocytosedmarker within large phagosomes. Contractile filamentsoccurred in the segments but were frequently lesswell-organized than in other parts of the myotubes. Thedescribed characteristics of the segments in rat myotubesdifferentiated in vitro bear resemblance to some of the characteristicsof the denervated endplate region of adult muscle.
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