| 1. |
- Arai, Takeru, et al.
(author)
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Axonal outgrowth in muscle grafts made acellular by chemical extraction
- 2000
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In: Restorative Neurology and Neuroscience. - 0922-6028. ; 17:4, s. 165-174
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Journal article (peer-reviewed)abstract
- Purpose: To compare nerve regeneration in autologous detergent extracted and freeze-thawed muscle grafts and to electrophoretically characterize the grafts. Methods: Autologous acellular muscle grafts were created either by freeze/thawing or by detergent extraction and then used to bridge a 10 mm gap in rat sciatic nerve. The autologous grafts were compared with respect to protein content, using electrophoresis preimplantation, and axonal outgrowth, Schwann cell and macrophage content, using immunocytochemistry (neurofilaments, S-100 protein, ED 1 macrophages) at 5-20 days postimplantation. Results: The extracted muscle grafts were elastic, but the amount of several proteins was reduced and laminin was still present at a position of basal laminae of the muscle fibers. The freeze/thawed grafts were brittle and lacked elasticity, but resulted in minor changes in major proteins. The axons regenerated through both types of grafts (initial delay 6 days and rate 0.7-0.8 mm/day), which shrunk in length by 25 %. There were no apparent differences with respect to Schwann cells and macrophages. Conclusions: The results suggest that detergent extracted mucle tissue, in which some basal lamina proteins remain but cells are removed, could present a new favourable option for nerve grafting.
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| 2. |
- Bergmark, Maria, et al.
(author)
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Experimental nerve compression and upregulation of CPON in DRG
- 2001
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In: NeuroReport. - 1473-558X. ; 12:17, s. 3783-3786
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Journal article (peer-reviewed)abstract
- Expression of C-terminal flanking peptide of neuropeptide Y (CPON) in DRG and cell proliferation (incorporation of BrdU) in sciatic nerve of rats following chronic nerve compression (silicone tubes with different internal diameters) was studied by immunocytochemistry. An increased number of CPON-positive neurons and cells incorporating BrdU was induced on the compressed side, most pronounced when a tight tube was used, while no cells expressed CPON or BrdU in intact nerves. The increase was transient and declined with time. Nerve compression induces transient cell proliferation in the nerve and expression of CPON in nerve cell bodies, but this is of a lesser magnitude than those following nerve transection.
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| 3. |
- Bontioti, Eleana N, et al.
(author)
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Regeneration and functional recovery in the upper extremity of rats after various types of nerve injuries.
- 2003
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In: Journal of the Peripheral Nervous System. - : Wiley. - 1085-9489 .- 1529-8027. ; 8:3, s. 159-168
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Journal article (peer-reviewed)abstract
- The aim was to establish an accurate, reproducible, and simple method to evaluate functional recovery after different types of nerve injuries to the brachial plexus of rats. To that end, pawprints, measured as distance between the first and fourth and second and third digits, were used for evaluation of injuries including crush injury, transection/repair, or graft repair of the median, ulnar, and radial nerves. Immunocytochemistry of the C-terminal flanking peptide of neuropeptide Y (CPON) and neurofilaments was used to investigate the cell body response and axonal outgrowth, respectively. Functional recovery was dependent on the severity as well as on the level of the lesion. Neither a single injury to the median nerve nor an injury to the ulnar nerve affected the pawprint, while an injury to both these nerves or a single injury to the radial nerve caused impairment of pawprints. There was a rapid recovery after crush injury to these nerves compared to previous reports of a similar injury to the sciatic nerve. The pattern of axonal outgrowth was related to the severity of the lesion. A conditioning lesion, i.e., an initial lesion of the same nerve preceding a test injury by a few days, of both motor/sensory fibers led to a quicker functional recovery. Surprisingly, conditioning of only sensory fibers had nearly the same effect. The cell body response was dependent on the level of the nerve lesion. The upper extremity of rats might be useful to evaluate the effects of new repair methods after nerve injuries using functional evaluation with pawprints as a simple and accurate method
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| 4. |
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| 5. |
- Dahlin, Lars, et al.
(author)
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Galanin expression in sensory neurons after nerve compression or transection.
- 2003
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In: NeuroReport. - 1473-558X. ; 14:3, s. 359-362
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Journal article (peer-reviewed)abstract
- Galanin is probably involved in nociceptive sensory processing in spinal cord. We investigated whether a common injury, peripheral nerve compression, induced up-regulation of galanin (immunocytochemistry) in sensory neurons in rats 6 or 14 days post-injury and compared the response with other nerve injuries. Sciatic nerve compression increased the number of galanin positive sensory neurons as compared to uninjured and contralateral dorsal root ganglia. Complete transection was more efficient than a partial transection and a slight compression injury as an inducer of galanin. Mainly small diameter sensory neurons became positive but also some large diameter neurons. We conclude that nerve compression up-regulates galanin in sensory neurons. The extent of the induction could be related to the severity of nerve injury.
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| 6. |
- Hou, Mingyan, et al.
(author)
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Capsaicin receptor immunoreactivity in the human trigeminal ganglion.
- 2002
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In: Neuroscience Letters. - 0304-3940. ; 330:3, s. 223-226
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Journal article (peer-reviewed)abstract
- The cloned capsaicin receptor, also known as vanilloid receptor subtype 1 (VR1) receptor, has been demonstrated to be an integral membrane protein with homology to a family of putative store-operated calcium channels. The VR1 receptor is activated not only by capsaicin but also by noxious heat and protons, and therefore it is suggested as a molecular integrator of chemical and physical stimuli that elicit pain. In the present study, indirect immunofluorescence detected a small number of neurons that are VR1 receptor immunoreactive (ir) (171 versus 1038 or 16% of all neuronal cell bodies) in the human trigeminal ganglion (TG). In addition, RT-PCR confirmed the presence of VR1 mRNA in the human TG. It has been hypothesized that TG neuronal cell bodies are the source of capsaicin-stimulated release of calcitonin gene-related peptide (CGRP), and hence co-localization experiments were performed. Around 10% of the VR1 receptor-ir is expressed on neurons that contain CGRP-ir (ten among 74) in the human TG, indicating that capsaicin may act through the VR1 receptor to modulate the release of CGRP and in turn to modulate pain. We observed that 8% of the VR1 receptor-ir neuronal cell bodies contain substance P-ir and 5% nitric oxide synthase. Capsaicin can release nitric oxide, CGRP and substance P from sensory nerves and contribute to central sensitization.
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| 7. |
- Jongsma, Helen, et al.
(author)
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Markedly reduced chronic nociceptive response in mice lacking the PAC1 receptor
- 2001
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In: NeuroReport. - 1473-558X. ; 12:10, s. 2215-2219
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Journal article (peer-reviewed)abstract
- The neuropeptide pituitary adenylate cyclase activating polypeptide (PACAP) has been proposed to have a role in nociception. Here we have used the formalin test, thermal laser stimulation and mechanical von Frey stimulation to investigate possible alteration of PAC1-/- mice nociceptive behaviour. Our finding, that PAC1-/- mice have a substantial, 75% decrease in nociceptive response during the late phase, provides clear evidence that the specific PACAP-receptor PAC1 is involved in the mediation of nociceptive responses during chronic conditions such as inflammation. PAC1-/- mice had small or no changes in the response to mechanical and thermal laser stimulation. This suggests a limited, if any, involvement of PAC1 in nociception after short-lasting stimuli. Injury-induced changes in DRG neuropeptide expression were more pronounced in PAC1-/- mice, implying neuroregulatory functions of PAC1.
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| 8. |
- Lindwall, Charlotta, et al.
(author)
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Inhibition of c-Jun phosphorylation reduces axonal outgrowth of adult rat nodose ganglia and dorsal root ganglia sensory neurons.
- 2004
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In: Molecular and Cellular Neuroscience. - : Elsevier BV. - 1044-7431. ; 27:3, s. 267-279
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Journal article (peer-reviewed)abstract
- The role of c-Jun activation for survival and regeneration of sensory neurons is unclear. Here we report that c-Jun N-terminal kinase (JNK)-mediated c-Jun activation is important for axonal outgrowth of sensory neurons in rat nodose and dorsal root ganglia (DRG). Peripheral severance of the vagus or the sciatic nerve resulted in a massive and rapid, but transient increase of the activated JNK (p-JNK) in neuronal nuclei, followed by c-Jun phosphorylation and activating transcription factor-3 (ATF3) induction. JNK inhibition by the selective JNK inhibitors SP600125 and (D)-JNKI1 did not affect neuronal survival in explanted or dissociated ganglia, but dramatically reduced axonal outgrowth, c-Jun activation, and ATF3 induction. Using retrograde labeling, we demonstrated that activated c-Jun (p-c-Jun) and ATF3 were associated with regenerative neurons. Taken together, our results suggest that JNK-mediated c-Jun activation is one of the first cell body reactions in response to nerve injury and that this activation and subsequent ATF3 induction are associated with axonal outgrowth.
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| 9. |
- Liu, Xiao-Lin, et al.
(author)
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Use of chemically extracted muscle grafts to repair extended nerve defects in rats
- 2001
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In: Scandinavian Journal of Plastic and Reconstructive Surgery and Hand Surgery. - : Informa UK Limited. - 1651-2073 .- 0284-4311. ; 35:4, s. 337-345
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Journal article (peer-reviewed)abstract
- Nerve regeneration, measured as axonal outgrowth, Schwann cell migration, macrophage invasion, and neovascularisation, was compared after repair of a 15 mm gap in rats' sciatic nerves using autologous muscle grafts made acellular either by freezing and thawing or by chemical extraction. Both extracted and freeze-thawed acellular muscle grafts could be used to bridge the defect. However, axons and Schwann cells, as shown by immunohistochemical staining for neurofilaments and S-100 protein, respectively, grew faster into the extracted muscle grafts than into the freeze-thawed acellular muscle grafts and somewhat more axons were observed in the former graft. There were no significant differences between the two graft types with respect to neovascularisation as showed by staining for endothelial alkaline phosphatase, and limited differences concerning invasion of macrophages (ED1 and ED2) as detected by immunocytochemistry. The results showed that chemically extracted muscle grafts could be used to bridge an extended nerve defect and that such grafts in some aspects were superior to freeze-thawed muscle grafts for extended gaps.
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| 10. |
- Magnusson, S, et al.
(author)
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Heme oxygenase-1, heme oxygenase-2 and biliverdin reductase in peripheral ganglia from rat, expression and plasticity
- 2000
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In: Neuroscience. - 1873-7544. ; 95:3, s. 821-829
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Journal article (peer-reviewed)abstract
- The expression of inducible and constitutive heme oxygenase and biliverdin reductase was studied in normal and cultured peripheral ganglia from adult rats, using immunocytochemistry and in situ hybridization. Dramatic changes were induced by one to two days' culturing of dorsal root ganglia, nodose ganglia, otic ganglia, sphenopalatine ganglia and superior cervical ganglia. An up-regulation of inducible heme oxygenase was found in satellite cells of the cultured nodose ganglia, dorsal root ganglia, sphenopalatine ganglia and otic ganglia, whereas only a few satellite cells in the superior cervical ganglia responded with an increase in inducible heme oxygenase immunoreactivity. In the superior cervical ganglia inducible heme oxygenase also appeared in a subpopulation of macrophages. During culturing, expression of inducible heme oxygenase immunoreactivity also increased in axons and in nerve cell bodies. In situ hybridization corroborated the immunocytochemical findings, revealing a strong up-regulation of inducible heme oxygenase messenger RNA in satellite cells, and less pronounced up-regulation in nerve cell bodies. Constitutive heme oxygenase immunoreactivity was found in most neurons in all of the ganglia studied. No significant changes in constitutive heme oxygenase immunoreactivity could be observed in cultured ganglia. Biliverdin reductase immunoreactivity was barely detectable in any of the normal ganglia; however, after culturing it appeared in axons, single nerve cell bodies and nerve cell nuclei. The results show that inducible heme oxygenase is up-regulated in peripheral ganglia after axonal injury, and suggest a role for carbon monoxide in cellular signaling and a requirement for the antioxidant (bilirubin) during the regeneration process.
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