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Zochodne DW, Verge VM, Cheng C, Sun H, Johnston J. Does diabetes target ganglion neurones? Progressive sensory neurone involvement in long-term experimental diabetes. Brain 2001; 124:2319-34. [PMID: 11673332 DOI: 10.1093/brain/124.11.2319] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Targeting of dorsal root ganglia by diabetes could account for the selective sensory abnormalities that patients with early diabetic polyneuropathy develop. In this work, we addressed survival, phenotype and gene expression in sensory neurones in lumbar dorsal root ganglia in a long-term model of experimental streptozotocin-induced diabetes in rats, designed to reflect human disease. Motor and sensory conduction slowing developed early, by the 2-month time point. At 2 months, sensory neurones had no detectable alterations in their calibre or gene expression, assessed using quantitative in situ hybridization studies for mRNA markers that included alpha CGRP, beta CGRP, NFM, t alpha 1-tubulin, SP, VIP, B50 (GAP43), galanin, somatostatin, PACAP, HSP27, c-jun, SNAP 25, p75, TrkA, TrkB and TrkC. By 12 months, however, diabetics had developed neurone perikaryal and distal axon atrophy, accompanied by generalized downregulation of mRNA expression, particularly of CGRP transcripts, PACAP, SP, NFM, p75, trkA and trkC. With the exception of HSP-27, no elevation in mRNAs that increase after injury, such as VIP, galanin, CCK, PACAP, B50 and t alpha 1-tubulin, was observed and constitutive levels, when detectable, trended towards lower rather than increased levels. There was relative preservation of neurone numbers at 12 months; only a non-significant trend towards fewer diabetic neurones was detected using a rigorous and systematic physical dissector counting approach through the entire L5 ganglia. There was no change in the relative populations of CGRP- and SP-immunoreactive neurones. Our findings indicate that even long-term experimental diabetes is associated with relative preservation of sensory neurone populations, but the neurones are atrophic and their gene expression is altered. This pattern of change differs from that following axotomy, implies a degenerative rather than an injury phenotype and has important implications for how such neurones might be rescued.
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MESH Headings
- Animals
- Calcitonin Gene-Related Peptide/metabolism
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Experimental/pathology
- Disease Progression
- Ganglia, Spinal/metabolism
- Ganglia, Spinal/pathology
- Gene Expression
- Male
- Nerve Fibers, Myelinated/metabolism
- Nerve Fibers, Myelinated/pathology
- Neurons, Afferent/metabolism
- Neurons, Afferent/pathology
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
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Affiliation(s)
- D W Zochodne
- Department of Clinical Neurosciences, University of Calgary, Alberta, Canada.
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2
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Jongsma Wallin H, Danielsen N, Johnston JM, Gratto KA, Karchewski LA, Verge VM. Exogenous NT-3 and NGF differentially modulate PACAP expression in adult sensory neurons, suggesting distinct roles in injury and inflammation. Eur J Neurosci 2001; 14:267-82. [PMID: 11553278 DOI: 10.1046/j.0953-816x.2001.01641.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Expression of pituitary adenylate cyclase-activating polypeptide in sensory neurons varies with injury or inflammation. The neurotrophins NGF and NT-3 are profound regulators of neuronal peptidergic phenotype in intact and injured sensory neurons. This study examined their potential for modulation of PACAP expression in adult rat with intact and injured L4-L6 spinal nerves with or without immediate or delayed intrathecal infusion of NT-3 or NGF. Results indicate that in L5 DRG, few trkC neurons express high levels of PACAP mRNA in the intact state, but many do following injury. The elevated expression in injured neurons is mitigated by NT-3 infusion, suggesting a role for NT-3 in returning the 'injured phenotype' back towards an 'intact phenotype'. NGF dramatically up-regulated PACAP expression in trkA-positive neurons in both intact and injured DRGs, implicating NGF as a positive regulator of PACAP expression in nociceptive neurons. Surprisingly, NT-3 modulates PACAP expression in an antagonistic fashion to NGF in intact neurons, an effect most evident in the trkA neurons not expressing trkC. Both NT-3 and NGF infusion results in decreased detection of PACAP protein in the region of the gracile nuclei, where central axons of the peripherally axotomized large sensory fibers terminate. NGF infusion also greatly increased the amount of PACAP protein detected in the portion of the dorsal horn innervated by small-medium size DRG neurons, while both neurotrophins appear able to prevent the decrease in PACAP expression observed in these afferents with injury. These results provide the first insights into the potential molecules implicated in the complex regulation of PACAP expression in sensory neurons.
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MESH Headings
- Afferent Pathways/cytology
- Afferent Pathways/drug effects
- Afferent Pathways/metabolism
- Animals
- Axotomy
- Ganglia, Spinal/drug effects
- Ganglia, Spinal/metabolism
- Ganglia, Spinal/physiopathology
- Gene Expression/drug effects
- Gene Expression/physiology
- Immunohistochemistry
- Inflammation/metabolism
- Inflammation/physiopathology
- Male
- Nerve Growth Factor/metabolism
- Neuroglia/cytology
- Neuroglia/drug effects
- Neuroglia/metabolism
- Neuronal Plasticity/drug effects
- Neuronal Plasticity/physiology
- Neurons, Afferent/drug effects
- Neurons, Afferent/metabolism
- Neuropeptides/drug effects
- Neuropeptides/metabolism
- Neurotrophin 3/metabolism
- Peripheral Nerve Injuries
- Peripheral Nerves/metabolism
- Peripheral Nerves/physiopathology
- Peripheral Nervous System Diseases/metabolism
- Peripheral Nervous System Diseases/physiopathology
- Pituitary Adenylate Cyclase-Activating Polypeptide
- Posterior Horn Cells/cytology
- Posterior Horn Cells/drug effects
- Posterior Horn Cells/metabolism
- RNA, Messenger/drug effects
- RNA, Messenger/metabolism
- Rats
- Rats, Wistar
- Receptor, trkA/genetics
- Receptor, trkC/genetics
- Sciatic Nerve/injuries
- Sciatic Nerve/physiopathology
- Sciatic Nerve/surgery
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3
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Zochodne DW, Verge VM, Cheng C, Höke A, Jolley C, Thomsen K, Rubin I, Lauritzen M. Nitric oxide synthase activity and expression in experimental diabetic neuropathy. J Neuropathol Exp Neurol 2000; 59:798-807. [PMID: 11005260 DOI: 10.1093/jnen/59.9.798] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The changes of nitric oxide synthase (NOS) activity and expression in experimental diabetic neuropathy have not been examined. Increases in ganglia NOS might be similar to those that follow axotomy, whereas declines in endothelial NOS (eNOS) and immunological NOS (iNOS) might explain dysfunction of microvessels or macrophages. In this work, we studied NOS activity in lumbar dorsal root ganglia (DRG) of rats with both short- and long-term experimental streptozotocin-induced diabetes and correlated it with expression of each of the 3 NOS isoforms. NOS enzymatic activity in DRG increased after 12 months of diabetes. This increase, however, was not accompanied by an increase in neuronal NOS immunohistochemistry or mRNA. Immunohistochemical and RT-PCR studies did not identify changes of eNOS expression in 12-month sciatic nerves or DRG from diabetics. Two-month diabetic DRG had increased eNOS mRNA and there was novel eNOS labeling of capsular DRG and perineurial cells. iNOS mRNA levels were lower in diabetics at both time points in peripheral nerves but were unchanged in DRG. Diabetic ganglia showed an increase in NOS activity not explained by novel NOS isoform synthesis. The increases may compensate for NO "quenching" by endproducts of glycosylation. Declines in iNOS may indicate impaired macrophage function.
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Affiliation(s)
- D W Zochodne
- Neuroscience Research Group and the Department of Clinical Neurosciences, University of Calgary, Alberta, Canada
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4
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Karchewski LA, Kim FA, Johnston J, McKnight RM, Verge VM. Anatomical evidence supporting the potential for modulation by multiple neurotrophins in the majority of adult lumbar sensory neurons. J Comp Neurol 1999; 413:327-41. [PMID: 10524342 DOI: 10.1002/(sici)1096-9861(19991018)413:2<327::aid-cne11>3.0.co;2-3] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Neurotrophins exert effects on sensory neurons through receptor tyrosine kinases (trks) and a common neurotrophin receptor (p75). Quantitative in situ hybridization studies were performed on serial sections to identify neurons expressing single or multiple neurotrophin trk receptor mRNA(s) in adult lumbar dorsal root ganglion (DRG) in order to examine the possibility of multi-neurotrophin modulation of phenotype via different trk receptors or various trk isoforms. Expression of mRNA encoding trkA, trkB, trkC, or p75 is restricted to select subpopulations representing approximately 41%, 33%, 43%, and 79% of DRG neurons, respectively. Colocalization studies reveal that approximately 10% of DRG neurons coexpress trkA and trkB mRNA; 19% coexpress trkA and trkC mRNA; and 18% coexpress trkB and trkC mRNA. Trilocalization of all three trk mRNAs is rare, with approximately 3-4% of neurons in this category. Overall incidence of expression of more than one full length trk mRNA occurs in approximately 40% of DRG neurons, whereas expression of individual trk mRNA is found in approximately 34%. Full length trk receptor mRNA is rarely detected without p75, implicating the latter in neuronal response to neurotrophins. Examination of two full-length isoforms of trkA reveal that they are coexpressed with relative levels of expression positively correlated. TrkC mRNAs corresponding to 14- or 39-amino acid insert isoforms colocalize with the non-insert trkC isoform, but the converse is not necessarily true. The data suggest that substantial subpopulations of adult sensory neurons may be modulated through interactions with multiple neurotrophins, the consequences of which are largely unknown.
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MESH Headings
- Animals
- Base Sequence
- Ganglia, Spinal/cytology
- Gene Expression
- In Situ Hybridization
- Lumbosacral Region/anatomy & histology
- Male
- Molecular Sequence Data
- Nerve Tissue Proteins/analysis
- Nerve Tissue Proteins/genetics
- Neurons, Afferent/physiology
- Phenotype
- Protein Isoforms/analysis
- Protein Isoforms/genetics
- RNA, Messenger/analysis
- Rats
- Rats, Wistar
- Receptor, Nerve Growth Factor/analysis
- Receptor, Nerve Growth Factor/genetics
- Receptor, trkA/analysis
- Receptor, trkA/genetics
- Receptor, trkB/analysis
- Receptor, trkB/genetics
- Receptor, trkC/analysis
- Receptor, trkC/genetics
- Receptors, Nerve Growth Factor/analysis
- Receptors, Nerve Growth Factor/genetics
- Superior Cervical Ganglion/cytology
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Affiliation(s)
- L A Karchewski
- Department of Anatomy & Cell Biology, University of Saskatchewan, Canada
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5
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Zinman LH, Lawrance G, Wang W, Verge VM, Dow KE, Maurice DH, Richardson PM, Riopelle RJ. Collaborative and reciprocal effects of ciliary neurotrophic factor and nerve growth factor on the neuronal phenotype of human neuroblastoma cells. J Neurochem 1998; 70:1411-20. [PMID: 9523557 DOI: 10.1046/j.1471-4159.1998.70041411.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We have probed the molecular basis of functional effects of ciliary neurotrophic factor (CNTF) and nerve growth factor (NGF) on aspects of the neuronal differentiation of LA-N-2 neuroblastoma cells. The influence of CNTF on the cholinergic phenotype can be accounted for by transcriptional/translational effects without implicating posttranslational mechanisms. Although both NGF receptors are expressed constitutively by LA-N-2 cells, CNTF has a marked stimulatory effect on trkA mRNA and protein. The NGF receptors are functional in serum-free conditions where they mitigate CNTF effects on cell adhesion but do not support process extension. Following priming by CNTF, NGF and CNTF have synergistic influences on process formation but not on choline acetyltransferase-specific activity.
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Affiliation(s)
- L H Zinman
- Department of Medicine, Queen's University, Kingston, Ontario, Canada
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6
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Abstract
A role for neurotrophins in mature primary sensory neurons persists, extending beyond that of promoting survival during development, to one of maintaining phenotypic and functional properties. Many adaptive changes that occur after peripheral axotomy and in axonal repair are believed to be influenced by altered availability of neurotrophic molecules to the neuron in this state. Indeed, administration of exogenous nerve growth factor counteracts many degenerative changes observed in the subpopulation of axotomized neurons which are nerve growth factor-responsive. Current efforts focus on defining actions of other neurotrophins (brain-derived neurotrophic factor, neurotrophin-3 and neurotrophin-4/5) in nerve injury and repair, and the intracellular pathways involved. Knowledge gained from work focusing on nerve growth factor and neurotrophin-3 in supporting maintenance or modulation of aspects of the differentiated state of adult primary sensory neurons is discussed.
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Affiliation(s)
- V M Verge
- Department of Anatomy and Cell Biology, University of Saskatchewan, Saskatoon, Canada
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7
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Verge VM, Richardson PM, Wiesenfeld-Hallin Z, Hökfelt T. Differential influence of nerve growth factor on neuropeptide expression in vivo: a novel role in peptide suppression in adult sensory neurons. J Neurosci 1995; 15:2081-96. [PMID: 7534343 PMCID: PMC6578124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
In this study the actions of NGF in regulating peptide expression were examined in vivo in adult rat primary sensory neurons. The hypothesis that NGF might tonically inhibit expression of some peptides was tested specifically. In situ hybridization and immunohistochemistry were used to detect presence or absence of alpha-CGRP, beta-CGRP, SP, SOM, VIP, CCK, NPY, and GAL as well as their mRNAs. In neurons in normal lumbar DRG alpha-CGRP, beta-CGRP, SP, and SOM are abundantly and heterogeneously expressed whereas few neurons have detectable VIP, CCK, NPY, or GAL. Two weeks following sciatic nerve transection, concentrations of alpha-CGRP, beta-CGRP, SP, and SOM plus their mRNAs have decreased to background in all but a few neurons. In contrast, VIP, CCK, NPY, and GAL are now synthesized in many neurons. Delayed intrathecal infusion of NGF (125 ng/microliter/hr) for 7 d, starting 2 weeks after injury counteracted the decrease in expression of alpha-CGRP, beta-CGRP and SP expression, but not SOM. This lack of influence of NGF on SOM is consistent with the absence of high-affinity NGF receptors and trk mRNA in SOM-positive neurons. Delayed infusion of NGF also reduced the number of neurons expressing VIP, CCK, NPY, and GAL after injury by approximately one-half in each subpopulation. Therefore, we suggest that NGF suppresses expression of these four peptides but only if the neurons also have NGF receptors. The results show that NGF can regulate peptide expression differentially and may also be part of the signal that allows reversion to normal of responses to injury as axons regenerate.
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Affiliation(s)
- V M Verge
- Department of Anatomy, University of Saskatchewan, Saskatoon, Canada
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8
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Friedman B, Kleinfeld D, Ip NY, Verge VM, Moulton R, Boland P, Zlotchenko E, Lindsay RM, Liu L. BDNF and NT-4/5 exert neurotrophic influences on injured adult spinal motor neurons. J Neurosci 1995; 15:1044-56. [PMID: 7869082 PMCID: PMC6577802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Adult motor neurons, like their immature antecedents, express the mRNA for the signaling receptor for brain-derived neurotrophic factor (BDNF) and for neurotrophin-4/5 (NT-4/5). However, while both BDNF and NT-4/5 support the survival of axotomized developing spinal motor neurons in vitro or in vivo, it is not known whether these factors continue to influence spinal motor neurons in adulthood. The present study tests if BDNF or NT-4/5 modulate the reactive responses of adult spinal motor neurons to nerve injury. We utilize sciatic nerve transection to axotomize the spinal motor neurons that form the retrodorsal lateral nucleus (RDLN) and show that, after axotomy, RDLN motor neurons lose ChAT immunoreactivity and also reexpress p75Ingfr, the low affinity receptor for all neurotrophin family members. Treatment with BDNF or NT-4/5 alters these effects of sciatic nerve transection. Both BDNF and NT-4/5 attenuate the loss of ChAT expression in axotomized RDLN motor neurons; thus, as compared to vehicle treatments, BDNF and NT-4/5 produce statistically significant increases in the optical density of ChAT immunostaining. Furthermore, BDNF and NT-4/5 also significantly increase the RDLN reexpression of p75Ingfr after sciatic nerve transection. Interestingly, essentially identical increases in RDLN ChAT and p75Ingfr immunostaining are produced by sciatic nerve crush injuries in the absence of exogenous neurotrophin treatment. These data show that treatment with exogenous BDNF and NT-4/5 changes the response of adult spinal motor neurons to sciatic nerve transection. Furthermore, these neurotrophins elicit reactive responses in axotomized motor neurons that mimic those produced by endogenous agents in regenerating crushed peripheral nerve.
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Affiliation(s)
- B Friedman
- Regeneron Pharmaceuticals Inc., Tarrytown, New York 10591
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9
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Abstract
We used in situ hybridization to localize trk, trkB and trkC mRNA, in rat and cat olfactory bulb. Expression of mRNA encoding truncated trkB receptors was seen in all layers, while only very modest full-length trkB expression could be detected. trkC hybridization was seen in all layers, most dense in the mitral cell layer. The localization of full-length tyrosine kinase trkB receptor in olfactory bulb and epithelium was examined with immunohistochemistry. trkB-like immunoreactivity was seen in the fila olfactoria, epithelium and in vitro, in olfactory sensory neurones. Since BDNF is expressed by olfactory sensory neurone target cells in the olfactory bulb, these data suggest that BDNF may act as a target derived neurotrophic factor in the primary olfactory system.
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Affiliation(s)
- M L Deckner
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
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10
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Abstract
Reactive non-neuronal cells express high levels of low-affinity neurotrophin receptor and truncated trkB receptors after spinal cord injury. Here we report that descending nerve fibres in the rat lateral spinal cord column show strong trkC-like immunoreactivity after traumatic spinal cord lesions in the adult rat. No change in trkC expression by glial cells could be detected by immunohistochemistry or in situ hybridization at the lesion site. The data suggest that regeneration of descending spinal cord axons could be encouraged by the trkC ligand, neurotrophin 3.
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Affiliation(s)
- J Frisén
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
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11
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Zhang X, Meister B, Elde R, Verge VM, Hökfelt T. Large calibre primary afferent neurons projecting to the gracile nucleus express neuropeptide Y after sciatic nerve lesions: an immunohistochemical and in situ hybridization study in rats. Eur J Neurosci 1993; 5:1510-9. [PMID: 7506974 DOI: 10.1111/j.1460-9568.1993.tb00219.x] [Citation(s) in RCA: 91] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Using immunohistochemistry and in situ hybridization, we studied changes in expression of some neuropeptides in large and medium-sized neurons in lumbar 4 and 5 rat dorsal root ganglia projecting to the gracile nucleus, in response to peripheral axotomy. Fourteen days after unilateral sciatic nerve transection, many large neurons and some medium-sized neurons in ipsilateral dorsal root ganglia were strongly neuropeptide Y-positive. Galanin-, vasoactive intestinal polypeptide (VIP)- and peptide histidine-isoleucine (PHI)-like immunoreactivities coexisted with neuropeptide Y-like immunoreactivity in some of these neurons. After axotomy numerous large and medium-sized cells contained neuropeptide Y mRNA in the ipsilateral ganglia, whereas no hybridization was seen in the contralateral or control ganglia. Cross-sectioned, large neuropeptide Y-positive fibres were observed in a somatotopically appropriate zone within the ipsilateral gracile fasciculus. A dense network of neuropeptide Y-immunoreactive, large nerve fibres and terminals was seen in the ipsilateral gracile nucleus. A small number of galanin- and VIP/PHI-like immunoreactive nerve fibres and terminals were also observed in adjacent sections. Neuropeptide Y-like immunoreactivity colocalized with galanin- or VIP/PHI-like immunoreactivity in some nerve fibres. None of these neuropeptide immunoreactivities could be detected in nerve fibres and terminals in the control or contralateral gracile nucleus. These findings suggest that neuropeptides, in addition to their role in small dorsal root ganglion neurons, may have a function in large and medium-sized dorsal root ganglion neurons projecting to laminae III and IV in the dorsal horn as well as to the gracile nuclei, as a part of their response to peripheral axotomy.
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Affiliation(s)
- X Zhang
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
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12
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Funakoshi H, Frisén J, Barbany G, Timmusk T, Zachrisson O, Verge VM, Persson H. Differential expression of mRNAs for neurotrophins and their receptors after axotomy of the sciatic nerve. J Cell Biol 1993; 123:455-65. [PMID: 8408225 PMCID: PMC2119843 DOI: 10.1083/jcb.123.2.455] [Citation(s) in RCA: 557] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The neurotrophin family includes NGF, brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and neurotrophin-4 (NT-4). Previous studies have demonstrated that expression of NGF and its low-affinity receptor is induced in nonneuronal cells of the distal segment of the transected sciatic nerve suggesting a role for NGF during axonal regeneration (Johnson, E. M., M. Taniuchi, and P. S. DeStefano. 1988. Trends Neurosci. 11:299-304). To assess the role of the other neurotrophins and the members of the family of Trk signaling neurotrophin receptors, we have here quantified the levels of mRNAs for BDNF, NT-3, and NT-4 as well as mRNAs for trkA, trkB, and trkC at different times after transection of the sciatic nerve in adult rats. A marked increase of BDNF and NT-4 mRNAs in the distal segment of the sciatic nerve was seen 2 wk after the lesion. The increase in BDNF mRNA was mediated by a selective activation of the BDNF exon IV promoter and adrenalectomy attenuated this increase by 50%. NT-3 mRNA, on the other hand, decreased shortly after the transection but returned to control levels 2 wk later. In Schwann cells ensheathing the sciatic nerve, only trkB mRNA encoding truncated TrkB receptors was detected with reduced levels in the distal part of the lesioned nerve. Similar results were seen using a probe that detects all forms of trkC mRNA. In the denervated gastrocnemius muscle, the level of BDNF mRNA increased, NT-3 mRNA did not change, while NT-4 mRNA decreased. In the spinal cord, only small changes were seen in the levels of neutrophin and trk mRNAs. These results show that expression of mRNAs for neurotrophins and their Trk receptors is differentially regulated after a peripheral nerve injury. Based on these results a model is presented for how the different neurotrophins could cooperate to promote regeneration of injured peripheral nerves.
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MESH Headings
- Animals
- Axons/chemistry
- Axons/ultrastructure
- Brain Chemistry
- Brain-Derived Neurotrophic Factor
- In Situ Hybridization
- Male
- Membrane Proteins/analysis
- Membrane Proteins/genetics
- Models, Biological
- Muscles/chemistry
- Muscles/ultrastructure
- Nerve Growth Factors/analysis
- Nerve Growth Factors/genetics
- Nerve Tissue Proteins/analysis
- Nerve Tissue Proteins/genetics
- Neurons/chemistry
- Neurons/ultrastructure
- Neurotrophin 3
- RNA, Messenger/analysis
- RNA, Messenger/genetics
- Rats
- Rats, Sprague-Dawley
- Receptor Protein-Tyrosine Kinases/analysis
- Receptor Protein-Tyrosine Kinases/genetics
- Receptor, Ciliary Neurotrophic Factor
- Receptor, trkC
- Receptors, Growth Factor/analysis
- Receptors, Growth Factor/genetics
- Receptors, Nerve Growth Factor/analysis
- Receptors, Nerve Growth Factor/genetics
- Sciatic Nerve/chemistry
- Sciatic Nerve/surgery
- Sciatic Nerve/ultrastructure
- Spinal Cord/chemistry
- Spinal Cord/ultrastructure
- Time Factors
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Affiliation(s)
- H Funakoshi
- Department of Medical Chemistry, Karolinska Institute, Stockholm, Sweden
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13
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Frisén J, Verge VM, Fried K, Risling M, Persson H, Trotter J, Hökfelt T, Lindholm D. Characterization of glial trkB receptors: differential response to injury in the central and peripheral nervous systems. Proc Natl Acad Sci U S A 1993; 90:4971-5. [PMID: 8389459 PMCID: PMC46635 DOI: 10.1073/pnas.90.11.4971] [Citation(s) in RCA: 203] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
In situ hybridization on sections from the adult rat peripheral and central nervous systems demonstrated that trkB mRNA was expressed not only by neurons but also by cells in central nervous system white matter as well as by Schwann cells in the sciatic nerve. In situ hybridization with an oligonucleotide complementary to the trkB tyrosine kinase domain could only demonstrate mRNA in neurons, indicating expression of truncated trkB receptors lacking the tyrosine kinase domain by glial cells. RNA blot analysis was performed on separately cultured central nervous system glial cells to study which cell types express trkB mRNA. Several transcripts encoding truncated trkB receptors were expressed at high levels in O-2A progenitors, astrocytes, and oligodendrocytes, but not trkB mRNA could be detected in microglia. The expression of trkB mRNA by glial cells in vivo was also investigated after injury; strongly elevated levels of mRNA encoding truncated receptors were detected in the glial scar formed after an incision in the spinal cord dorsal funiculus. In contrast, in the cut sciatic nerve, trkB mRNA decreased distal to the transection, and by 3 weeks only very low levels of mRNA could be detected. Immunoelectron microscopy located trkB-like immunoreactivity to axons and Schwann cells in the sciatic nerve. The expression of truncated trkB receptors by astrocytes, oligodendrocytes, and Schwann cells and the altered levels in response to injury indicate that glial trkB receptors may serve an important function in the intact and injured nervous system.
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MESH Headings
- Animals
- Animals, Newborn
- Axons/physiology
- Axons/ultrastructure
- Cells, Cultured
- Embryo, Mammalian
- Hippocampus/physiology
- Laminectomy
- Male
- Membrane Proteins/genetics
- Membrane Proteins/metabolism
- Microscopy, Immunoelectron
- Neurons/cytology
- Neurons/physiology
- Neurons/ultrastructure
- RNA, Messenger/analysis
- RNA, Messenger/metabolism
- Rats
- Rats, Wistar
- Receptor, Ciliary Neurotrophic Factor
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/metabolism
- Schwann Cells/physiology
- Schwann Cells/ultrastructure
- Sciatic Nerve/injuries
- Sciatic Nerve/physiology
- Spinal Cord/physiology
- Transcription, Genetic
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Affiliation(s)
- J Frisén
- Department of Neurochemistry, Max-Planck Institute for Psychiatry, Martinsried, Germany
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14
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Xu XJ, Puke MJ, Verge VM, Wiesenfeld-Hallin Z, Hughes J, Hökfelt T. Up-regulation of cholecystokinin in primary sensory neurons is associated with morphine insensitivity in experimental neuropathic pain in the rat. Neurosci Lett 1993; 152:129-32. [PMID: 8515864 DOI: 10.1016/0304-3940(93)90500-k] [Citation(s) in RCA: 134] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We examined the distribution of mRNA for the peptide cholecystokinin (CCK) with in situ hybridization in adult rat lumbar dorsal root ganglia following unilateral section of the sciatic nerve, as well as the effect of systemic CI 988, a selective antagonist of the CCK type B receptor, applied alone or in combination with intrathecal (i.t.) morphine, on the self-mutilating behavior of rats (autotomy) after axotomy, a sign of neuropathic pain and/or dysesthesia. There was a dramatic increase in the number of neurons in dorsal root ganglia synthesizing the peptide cholecystokinin (CCK) after sciatic nerve section. Furthermore, the autotomy behavior of rats was significantly inhibited by chronic i.t. administration of morphine in conjunction with subcutaneous (s.c.) injection of CI 988. Neither i.t. morphine nor s.c. CI 988 alone produced a comparable effect on autotomy. Our results suggested that up-regulation of the mRNA for CCK in primary afferents after nerve injury may be related to the clinical phenomenon of opioid insensitivity. Thus, coadministration of CCK antagonists in combination with opioids may offer a new approach in treating neuropathic pain.
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Affiliation(s)
- X J Xu
- Department of Clinical Physiology, Huddinge University Hospital, Karolinska Institute, Sweden
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Verge VM, Wiesenfeld-Hallin Z, Hökfelt T. Cholecystokinin in mammalian primary sensory neurons and spinal cord: in situ hybridization studies in rat and monkey. Eur J Neurosci 1993; 5:240-50. [PMID: 8261105 DOI: 10.1111/j.1460-9568.1993.tb00490.x] [Citation(s) in RCA: 87] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The peptide cholecystokinin (CCK) has been suggested to be involved in nociception, but its exact localization at the level of the spinal cord and in spinal ganglia has been a controversial issue. Therefore the distribution of messenger RNA (mRNA) for CCK was studied by in situ hybridization using oligonucleotide probes on sections of adult rat lumbar dorsal root ganglia following unilateral section of the sciatic nerve and on sections of untreated monkey trigeminal ganglia, spinal cord and spinal ganglia from all levels. For comparison, calcitonin gene-related peptide (CGRP) mRNA was also studied in the monkey tissue using the same techniques. Peripheral sectioning of the sciatic nerve in the rat resulted in the appearance of detectable CCK mRNA in up to 30% of remaining ipsilateral L4 and L5 dorsal root ganglion neurons 3 weeks after surgery, with a distinct but more limited appearance also in the contralateral ganglia. No cells, or only single cells, could be seen in normal control rat ganglia. In contrast, in the normal monkey, approximately 20% of dorsal root ganglion neurons, regardless of spinal level, and 10% of trigeminal ganglia neurons expressed mRNA for CCK. CGRP mRNA was expressed at detectable levels in approximately 80% of these monkey dorsal root ganglion neurons. In the monkey spinal cord, CCK mRNA was detected in the dorsal horn and in motoneurons, whereas CGRP mRNA was only seen in motoneurons. The present results suggest that CCK peptides can be involved in sensory processing in the dorsal horn of the spinal cord in normal monkeys and in rats after peripheral nerve injury, adding one more possible excitatory peptide to the group of mediators in the dorsal horn.
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Affiliation(s)
- V M Verge
- Department of Histology and Neurobiology, Karolinska Institute, Stockholm, Sweden
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16
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Verge VM, Xu XJ, Langel U, Hökfelt T, Wiesenfeld-Hallin Z, Bartfai T. Evidence for endogenous inhibition of autotomy by galanin in the rat after sciatic nerve section: demonstrated by chronic intrathecal infusion of a high affinity galanin receptor antagonist. Neurosci Lett 1993; 149:193-7. [PMID: 7682681 DOI: 10.1016/0304-3940(93)90769-h] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We have studied the effect of M-35 [Galanin(1-12)-Pro-bradykinin(2-9)-amide], a newly developed high affinity antagonist for galanin receptors, on self-mutilation (autotomy) behavior of the deafferented limb in rats after unilateral section of sciatic nerves. M-35 (1.3 micrograms/microliters) or saline was applied to the lumbar spinal cord through a chronically implanted intrathecal catheter at a rate of 0.5 microliter/h for 10 days post axotomy via an osmotic minipump. Axotomized rats infused with M-35 autotomized significantly more than those perfused intrathecally with saline or those axotomized rats not implanted with an intrathecal catheter. The severity of autotomy was also markedly greater in the group treated with M-35 than in the two other groups. M-35 did not noticeably influence either the galanin mRNA level in corresponding dorsal root ganglia and dorsal horn region or the percent of lumbar sensory neurons expressing detectable levels of mRNA for galanin. It is suggested that galanin can endogenously suppress autotomy behavior in rats after nerve injury and thus may play an important role in the control of the development of neuropathic pain.
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Affiliation(s)
- V M Verge
- Department of Histology and Neurobiology, Karolinska Institute, Stockholm, Sweden
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17
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Zhang X, Verge VM, Wiesenfeld-Hallin Z, Piehl F, Hökfelt T. Expression of neuropeptides and neuropeptide mRNAs in spinal cord after axotomy in the rat, with special reference to motoneurons and galanin. Exp Brain Res 1993; 93:450-61. [PMID: 7686109 DOI: 10.1007/bf00229360] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The extent to which the plasticity in peptide expression observed in developing spinal motoneurons occurs following proximal peripheral axotomy in the adult rat was examined using in situ hybridization and immunohistochemical techniques to visualize the changes. Transient upregulation of galanin, vasoactive intestinal polypeptide (VIP) and substance P messenger ribonucleic acids (mRNAs) was observed within subpopulations of motoneurons ipsilateral to lesion for periods lasting 2-3 weeks after injury. In contrast, the axotomy-induced heterogenous increases in somatostatin and neuropeptide tyrosine mRNA expression in ipsilateral motoneurons remained elevated, or, in the case of somatostatin, continued to increase for the time period studied (1 month). Immunohistochemical analysis agreed with the in situ hybridization results, showing some motoneurons within the injured ventral horn to contain galanin-, VIP- or somatostatin-like immunoreactivity. In some instances, galanin-immunoreactive motoneurons colocalized with calcitonin gene-related peptide immunoreactivity. Most of the neurons expressing the injury-induced peptides appeared large, presumably alpha-motoneurons but there were also many small neurons expressing galanin in the ventral horn ipsilateral to lesion. This may represent evidence for peptide synthesis in gamma-motoneurons. The only peptide mRNA studied to be down-regulated in response to axotomy was enkephalin. The results show that peptide expression in injured motoneurons is dramatically altered, the significance of which remains to be determined.
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Affiliation(s)
- X Zhang
- Department of Histology and Neurobiology, Karolinska Institutet, Stockholm, Sweden
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Frisén J, Verge VM, Cullheim S, Persson H, Fried K, Middlemas DS, Hunter T, Hökfelt T, Risling M. Increased levels of trkB mRNA and trkB protein-like immunoreactivity in the injured rat and cat spinal cord. Proc Natl Acad Sci U S A 1992; 89:11282-6. [PMID: 1333605 PMCID: PMC50534 DOI: 10.1073/pnas.89.23.11282] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Expression of neurotrophins and neurotrophin receptors was examined with in situ hybridization and immunohistochemical techniques 10 days to 6 weeks after ventral or dorsal funiculus spinal cord lesions in adult rats and cats, lesions that have previously been shown to allow axon regrowth. Strongly elevated levels of trkB mRNA were seen in the scar tissue formed in the white matter after both types of lesions. Only small increases were detected for nerve growth factor, brain-derived neurotrophic factor, neurotrophin 3, neurotrophin 4, trk, and trkC mRNA in response to the injuries. trkB protein-like immunoreactivity was increased in the regions that showed elevated levels of trkB mRNA. EM localized this immunoreactivity to neurons, astrocytes, and leptomeningeal cells. Neurofilament immunolabeling and axonal tracing demonstrated that nerve fibers in the scar tissue were concentrated to areas that showed strong trkB protein-like immunoreactivity. The findings implicate a role for neurotrophin receptors in axonal sprouting and glial reactions in the injured spinal cord.
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Affiliation(s)
- J Frisén
- Department of Anatomy, Karolinska Institute, Stockholm, Sweden
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19
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Verge VM, Xu Z, Xu XJ, Wiesenfeld-Hallin Z, Hökfelt T. Marked increase in nitric oxide synthase mRNA in rat dorsal root ganglia after peripheral axotomy: in situ hybridization and functional studies. Proc Natl Acad Sci U S A 1992; 89:11617-21. [PMID: 1280832 PMCID: PMC50604 DOI: 10.1073/pnas.89.23.11617] [Citation(s) in RCA: 198] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Using in situ hybridization, we studied nitric oxide (NO) synthase (EC 1.14.23.-) mRNA in lumbar dorsal root ganglia after peripheral transection of the sciatic nerve in rats. The effect of the NO synthase inhibitor N omega-nitro-L-arginine methyl ester on the nociceptive flexor reflex was also studied in axotomized rats. Nerve section induced a dramatic increase in number of NO synthase mRNA-positive cells in the ipsilateral dorsal root ganglia. In some of these cells the peptides galanin and/or vasoactive intestinal polypeptide and/or neuropeptide Y were also strongly up-regulated. Intravenous administration of nitro-L-arginine methyl ester blocked spinal hyperexcitability at much lower dosages in axotomized than in normal animals. The results suggest involvement of NO in the function of lumbar sensory neurons, especially after axotomy, perhaps preferentially at peripheral sites.
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Affiliation(s)
- V M Verge
- Department of Histology and Neurobiology, Karolinska Institute, Stockholm, Sweden
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20
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Verge VM, Merlio JP, Grondin J, Ernfors P, Persson H, Riopelle RJ, Hökfelt T, Richardson PM. Colocalization of NGF binding sites, trk mRNA, and low-affinity NGF receptor mRNA in primary sensory neurons: responses to injury and infusion of NGF. J Neurosci 1992; 12:4011-22. [PMID: 1403097 PMCID: PMC6575949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The distributions of mRNAs for the protooncogene trk and the low-affinity NGF receptor (LNGFR) were studied by hybridization with oligonucleotide probes on sections of adult rat primary sensory and sympathetic ganglia. For comparison with high-affinity binding sites, adjacent sections were processed for NGF receptor radioautography. Among neurons in lumbar dorsal root ganglia and trigeminal ganglia, trk mRNA and NGF-binding sites were closely colocalized; this finding together with previous direct evidence in other cell types is taken to indicate that trk protein is an essential component of the high-affinity NGF receptor in adult sensory neurons. In lumbar dorsal root ganglia and trigeminal ganglia, abundant LNGFR mRNA was found in all neurons with strong 125I-NGF labeling and on additional neurons lacking high-affinity NGF-binding sites. The presence of abundant LNGFR in neurons with high-affinity receptors could be the cause and/or consequence of their ability to respond to NGF. Neurons with abundant LNGFR mRNA but few high-affinity NGF-binding sites may have receptors for other members of the neurotrophin family. In nodose ganglia, neurons with high concentrations of LNGFR mRNA greatly outnumbered the small percentage with abundant trk mRNA. Following intrathecal infusion of NGF to otherwise normal dorsal root ganglia, the concentrations of LNGFR mRNA but not those of trk mRNA and NGF-binding sites were increased in NGF-responsive neurons. The usual single normal pattern of frequency histograms of LNGFR labeling indices became bimodal in response to NGF. Concentrations of NGF-binding sites, LNGFR mRNA, and trk mRNA were all decreased by peripheral nerve transection and restored by exogenous NGF, the restoration being complete for LNGFR mRNA and partial for trk mRNA and NGF-binding sites. The data indicate that NGF can regulate both LNGFR and trk mRNAs but do not clarify the possible contribution of the LNGFR protein to high-affinity binding sites.
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Affiliation(s)
- V M Verge
- Division of Neurosurgery, McGill University, Montreal, Canada
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21
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Lindå H, Piehl F, Dagerlind A, Verge VM, Arvidsson U, Cullheim S, Risling M, Ulfhake B, Hökfelt T. Expression of GAP-43 mRNA in the adult mammalian spinal cord under normal conditions and after different types of lesions, with special reference to motoneurons. Exp Brain Res 1992; 91:284-95. [PMID: 1333987 DOI: 10.1007/bf00231661] [Citation(s) in RCA: 62] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In situ hybridization histochemistry was used to detect cell bodies expressing mRNA encoding for the phosphoprotein GAP-43 in the lumbosacral spinal cord of the adult rat, cat and monkey under normal conditions and, in the cat and rat, also after different types of lesions. In the normal spinal cord, a large number of neurons throughout the spinal cord gray matter were found to express GAP-43 mRNA. All neurons, both large and small, in the motor nucleus (Rexed's lamina IX) appeared labeled, indicating that both alpha and gamma motoneurons express GAP-43 mRNA under normal conditions. After axotomy by an incision in the ventral funiculus or a transection of ventral roots or peripheral nerves, GAP-43 mRNA was clearly upregulated in axotomized motoneurons, including both alpha and gamma motoneurons. An increase in GAP-43 mRNA expression was already detectable 24 h postoperatively in lumbar motoneurons both after a transection of the sciatic nerve at knee level and after a transection of ventral roots. At this time, a stronger response was seen in the motoneurons which had been subjected to the distal sciatic nerve transection than was apparent for the more proximal ventral root lesion. An upregulation of GAP-43 mRNA could also be found in intact motoneurons located on the side contralateral to the lesion, but only after a peripheral nerve transection, indicating that the concomitant influence of dorsal root afferents may play a role in GAP-43 mRNA regulation. However, a dorsal root transection alone did not seem to have any detectable influence on the expression of GAP-43 mRNA in spinal motoneurons, while the neurons located in the superficial laminae of the dorsal horn responded with an upregulation of GAP-43 mRNA. The presence of high levels of GAP-43 in neurons has been correlated with periods of axonal growth during both development and regeneration. The role for GAP-43 in neurons under normal conditions is not clear, but it may be linked with events underlying remodelling of synaptic relationships or transmitter release. Our findings provide an anatomical substrate to support such a hypothesis in the normal spinal cord, and indicate a potential role for GAP-43 in axon regeneration of the motoneurons, since GAP-43 mRNA levels was strongly upregulated following both peripheral axotomy and axotomy within the spinal cord.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- H Lindå
- Department of Anatomy, Karolinska Institutet, Stockholm, Sweden
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22
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Abstract
The extracellular environment of the neuron provides a heterogeneous milieu of survival and growth modulating molecular species subserving regulatory signals that operate in development, mediate activity-dependent enduring changes in synaptic connectivity, and promote or inhibit survival and axonal regeneration following insult. Parallel distributed processing networks in neurons, activated by these molecular species, can likely be recruited selectively to serve specific needs of the organism.
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Affiliation(s)
- R J Riopelle
- Department of Medicine, Queen's University, Kingston, Ontario, Canada
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Verge VM, Tetzlaff W, Bisby MA, Richardson PM. Influence of nerve growth factor on neurofilament gene expression in mature primary sensory neurons. J Neurosci 1990; 10:2018-25. [PMID: 2113088 PMCID: PMC6570291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
To analyze the possible influence of nerve growth factor (NGF) on neurofilament synthesis in primary sensory neurons, adjacent cryostat sections of lumbar dorsal root ganglia (DRG) from adult rats were processed for either NGF-receptor radioautography or in situ hybridization with a neurofilament cDNA probe. Labeling by both procedures was quantified with computer assistance for approximately 300 neurons in each of selected ganglia. For uninjured neurons, no correction was detected between NGF binding and neurofilament mRNA, even after infusion of NGF into the lumbar subarachnoid space for 1 week. One or 3 weeks after sciatic nerve transection, neurofilament labeling densities in large DRG neurons were sharply reduced and the normal bimodal pattern in frequency histograms had become unimodal. Intrathecal infusion of NGF counteracted this injury-induced reduction of neurofilament mRNA but only in neurons with high-affinity NGF receptors. To explain the effects of NGF on axotomized neurons and the normal diversity of neurofilament gene expression among neurons with NGF receptors, we postulate that NGF permits NGF-sensitive DRG neurons to respond differentially to a second factor stimulating neurofilament synthesis.
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Affiliation(s)
- V M Verge
- Division of Neurosurgery, Montreal General Hospital, Quebec, Canada
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24
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Verge VM, Tetzlaff W, Richardson PM, Bisby MA. Correlation between GAP43 and nerve growth factor receptors in rat sensory neurons. J Neurosci 1990; 10:926-34. [PMID: 2156965 PMCID: PMC6570121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
In mature rat sensory neurons, expression of the gene for the growth-associated protein, GAP43, was studied by in situ hybridization with a cDNA probe. Among neurons in normal lumbar dorsal root ganglia, labeling for GAP43 mRNA was heterogeneous, approximately one-half of the neurons being densely labeled. To characterize the latter population, individual neurons were examined in adjacent sections processed either for GAP43 hybridization or NGF-receptor radioautography. Virtually all neurons with high-affinity NGF binding sites had high basal levels of GAP43 mRNA and most GAP43-positive neurons bore NGF receptors. Another NGF-responsive population, sympathetic neurons in the superior cervical ganglion, also had high basal concentrations of GAP43 mRNA. Further co-localization studies in dorsal root ganglia were performed with immunohistochemistry for somatostatin and enzyme histochemistry for acid phosphatase. The latter 2 groups of sensory neurons have been previously shown to lack high-affinity receptors and were here shown to have low basal concentrations of GAP43 mRNA. From this and earlier studies, it can be assumed that substance P-immunoreactive neurons and strongly positive CGRP neurons synthesize GAP43 at high basal rate. One week following peripheral nerve transection, almost all neurons had high concentrations of GAP43 mRNA without correlation with NGF binding. Intrathecal infusion of NGF after the sciatic nerve was cut did not strongly influence this post-traumatic elevation in GAP mRNA. In normal dorsal root ganglia, neurons that have high-affinity NGF binding sites and are therefore potentially responsive to NGF also have high basal rates of synthesis of GAP43.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- V M Verge
- Division of Neurosurgery, Montreal General Hospital, Canada
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25
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Mandelzys A, Cooper E, Verge VM, Richardson PM. Nerve growth factor induces functional nicotinic acetylcholine receptors on rat sensory neurons in culture. Neuroscience 1990; 37:523-30. [PMID: 2133357 DOI: 10.1016/0306-4522(90)90420-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Neonatal sensory neurons from rat nodose ganglia express nicotinic acetylcholine receptors when grown in tissue culture without other cell types. The present study investigates the role of nerve growth factor in inducing these receptors. Nerve growth factor has little effect on the growth and survival of nodose neurons in culture, although most neurons were found by quantitative radioautography to have high-affinity nerve growth factor receptors. Nerve growth factor strongly influenced the expression of nicotinic receptors on these neurons: the proportion of acetylcholine-sensitive neurons was approximately 60% in cultures with nerve growth factor compared with 15% in cultures grown without nerve growth factor. The proportion of acetylcholine-sensitive neurons increased over the first week, plateaued by day 12 and remained high for at least three weeks. In contrast, without NGF, the proportion of acetylcholine-sensitive neurons was low throughout the three-week period. The results indicate that nerve growth factor is an important factor in promoting nicotinic receptors on these neurons in culture.
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Affiliation(s)
- A Mandelzys
- Department of Physiology, McGill University, Montreal, Quebec, Canada
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26
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Verge VM, Richardson PM, Benoit R, Riopelle RJ. Histochemical characterization of sensory neurons with high-affinity receptors for nerve growth factor. J Neurocytol 1989; 18:583-91. [PMID: 2559166 DOI: 10.1007/bf01187079] [Citation(s) in RCA: 142] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Approximately one half of the neurons in the lumbar dorsal root ganglion of adult rats display high-affinity receptors for nerve growth factor (NGF). To ascertain which types of sensory neurons are potentially responsive to NGF, adjacent cryostat sections of rat dorsal root ganglia were processed either for NGF-receptor using radioautography or by one of four histochemical procedures. Histograms of the densities of neuronal labelling by radioiodinated NGF were examined for subpopulations of lumbar sensory neurons with thiamine monophosphatase enzyme activity or with immunoreactivity for calcitonin gene-related peptide (CGRP), substance P, or somatostatin. Virtually all neurons with strong CGRP immunoreactivity had high-affinity NGF binding sites, although some neurons with faintly positive CGRP immunoreactivity lacked such NGF binding. A subpopulation of large neurons, approximately 5% of the total, had dense labelling by 125I-NGF but were not stained by this immunohistochemical technique for CGRP. Of the three major populations of small neurons those with substance P immunoreactivity were consistently and heavily labelled by radioiodinated NGF whereas those with somatostatin immunoreactivity or thiamine monophosphatase activity were not specifically labelled by radioautography. For these primary sensory neurons in mature rats the genes for substance P and CGRP seem to be strongly expressed only in neurons capable of responding to NGF. On the other hand, neurons containing somatostatin and thiamine monophosphatase invariably lack high-affinity NGF receptors.
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Affiliation(s)
- V M Verge
- Division of Neurosurgery, McGill University, Canada
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27
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Verge VM, Riopelle RJ, Richardson PM. Nerve growth factor receptors on normal and injured sensory neurons. J Neurosci 1989; 9:914-22. [PMID: 2538586 PMCID: PMC6569964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The density and binding properties of receptors for nerve growth factor (NGF) in normal and injured sensory neurons have been analyzed by quantitative radioautography following incubation of tissue sections with radioiodinated NGF. The technique is designed to study binding sites that are half-maximally saturated by picomolar concentrations of NGF: Additional sites of lower affinity have not been emphasized. In normal adult rats, approximately half of lumbar sensory neurons have high-affinity receptors for NGF. One month after the sciatic nerve is cut, the mean number of high-affinity sites on heavily labeled neurons in the fifth lumbar dorsal root ganglion falls to less than 20% of normal values because of reduced receptor density and cell volume. Neurons with high-affinity receptors are more liable to atrophy after injury than those lacking such receptors. Receptors are lost not only in the cell bodies of sensory neurons but also on their peripheral and central processes. Delayed administration of NGF to the sciatic nerve 3 weeks after it is cut restores the receptor density to normal values and partially restores the neuronal cell volume. As part of the response to axonal injury and possibly because the cell body is deprived of NGF, fewer high-affinity receptors are displayed by sensory neurons. For at least 3 weeks after nerve transection, neurons that are atrophic and depleted of NGF receptors can be resuscitated by exogenous NGF.
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Affiliation(s)
- V M Verge
- Division of Neurosurgery, Montreal General Hospital, Canada
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28
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Abstract
The binding properties of receptors for nerve growth factor (NGF) in the adult rat nervous system have been analyzed in membrane fractions from discrete regions and in radioautographs of tissue sections. Steady-state experiments with both preparations revealed specific binding of radioiodinated NGF that was heterogeneous in distribution and affinity. Of the regions in the central nervous system that were sampled, the dorsal spinal cord and basal forebrain were richest in NGF receptor. By 4 independent methods of analysis a high-affinity binding site was detected in the basal forebrain with half-maximal saturation estimated at 20-60 pM NGF. Binding at lower affinity was also seen but difficult to analyze quantitatively. Cross-linking studies followed by electrophoresis showed the NGF receptor in the rat basal forebrain to have an apparent molecular weight of 90 kDa. The binding and molecular properties of NGF receptors on adult mammalian neurons resemble those described on other NGF-responsive cells.
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Affiliation(s)
- R J Riopelle
- Division of Neurology, Queen's University, Kingston, Ont., Canada
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29
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Riopelle RJ, Richardson PM, Verge VM. Distribution and characteristics of nerve growth factor binding on cholinergic neurons of rat and monkey forebrain. Neurochem Res 1987; 12:923-8. [PMID: 2825055 DOI: 10.1007/bf00966314] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In sections of rat forebrain, perikarya labeled radioautographically with 125I-NGF resembled cholinesterase-positive neurons in their distribution within striatum and basal forebrain. Neurons with NGF receptors were also visualized in radioautographs prepared from the basal forebrain of a cerebrus monkey. Present techniques fail to detect axons projecting from basal forebrain to hippocampus or cortex which have been shown to take up NGF selectively in retrograde transport studies. In studies with membrane-enriched preparations from rat, high-affinity binding of 125I-NGF (half maximal saturation in the 15-30 pM range) was detected in basal forebrain and striatum; lower levels of high-affinity binding were seen in hippocampus and neocortex. The binding and molecular properties of these receptors are similar to those described in other NGF-responsive tissues. These observations are further evidence supporting a biological role for NGF on some forebrain cholinergic neurons in adult rat.
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30
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Abstract
Regeneration of crushed axons in rat dorsal spinal roots was measured to investigate the transganglionic influence of an additional peripheral axonal injury. The right sciatic nerve was cut at the hip and the left sciatic nerve was left intact. One week later, both fifth lumbar dorsal roots were crushed and subsequently, regeneration in the two roots was assessed with one of two anatomical techniques. By anterograde tracing with horseradish peroxidase, the maximal rate of axonal regrowth towards the spinal cord was estimated to be 1.0 mm/day on the left and 3.1 mm/day on the right. Eighteen days after crush injury, new, thinly myelinated fibers in the root between crush site and spinal cord were 5-10 times more abundant ipsilateral to the sciatic nerve transection. The central axons of primary sensory neurons regenerate more quickly if the corresponding peripheral axons are also injured.
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31
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Richardson PM, Verge VM. The induction of a regenerative propensity in sensory neurons following peripheral axonal injury. J Neurocytol 1986; 15:585-94. [PMID: 3772404 DOI: 10.1007/bf01611859] [Citation(s) in RCA: 84] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Injury of the peripheral axons of primary sensory neurons has been previously shown to increase the probability that the corresponding central axons would grow from the injured spinal cord into a peripheral nerve graft. This phenomenon has been used to investigate the nature of extrinsic cues from injured nerves that enhanced regenerative propensity within sensory neurons. In 13 groups of rats, a segment of the right sciatic nerve was grafted to the dorsal columns of the spinal cord and the left sciatic nerve was subjected to mechanical injury, injection of colchicine or infusion of nerve growth factor. Subsequently, neurons in lumbar dorsal root ganglia with axons growing from the spinal cord into a graft were identified by retrograde perikaryal labelling and compared for the two sides. The aim was to mimic or modify the inductive effect of nerve transaction by alternative or additional manipulation of the nerve. Growth of central axons was less enhanced by peripheral axonal interruption if the length of the proximal stump was increased or if a distal stump was present to permit rapid regeneration. However, the regenerative response following nerve transection was altered little by crushing the proximal stump or injecting it with colchicine or nerve growth factor. It is suggested that sensory neurons are stimulated to regenerate by peripheral axonal injuries that reduce some normal retrograde regulatory influence of Schwann cells.
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