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Barrett MS, Bauer TC, Li MH, Hegarty DM, Mota CMD, Amaefuna CJ, Ingram SL, Habecker BA, Aicher SA. Ischemia-reperfusion myocardial infarction induces remodeling of left cardiac-projecting stellate ganglia neurons. Am J Physiol Heart Circ Physiol 2024; 326:H166-H179. [PMID: 37947434 PMCID: PMC11213476 DOI: 10.1152/ajpheart.00582.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 10/23/2023] [Accepted: 11/08/2023] [Indexed: 11/12/2023]
Abstract
Neurons in the stellate ganglion (SG) provide sympathetic innervation to the heart, brown adipose tissue (BAT), and other organs. Sympathetic innervation to the heart becomes hyperactive following myocardial infarction (MI). The impact of MI on the morphology of cardiac sympathetic neurons is not known, but we hypothesized that MI would stimulate increased cell and dendritic tree size in cardiac neurons. In this study, we examined the effects of ischemia-reperfusion MI on sympathetic neurons using dual retrograde tracing methods to allow detailed characterization of cardiac- and BAT-projecting neurons. Different fluorescently conjugated cholera toxin subunit B (CTb) tracers were injected into the pericardium and the interscapular BAT pads, respectively. Experimental animals received a 45-min occlusion of the left anterior descending coronary artery and controls received sham surgery. One week later, hearts were collected for assessment of MI infarct and SGs were collected for morphological or electrophysiological analysis. Cardiac-projecting SG neurons from MI mice had smaller cell bodies and shorter dendritic trees compared with sham animals, specifically on the left side ipsilateral to the MI. BAT-projecting neurons were not altered by MI, demonstrating the subpopulation specificity of the response. The normal size and distribution differences between BAT- and cardiac-projecting stellate ganglion neurons were not altered by MI. Patch-clamp recordings from cardiac-projecting left SG neurons revealed increased spontaneous excitatory postsynaptic currents despite the decrease in cell and dendritic tree size. Thus, increased dendritic tree size does not contribute to the enhanced sympathetic neural activity seen after MI.NEW & NOTEWORTHY Myocardial infarction (MI) causes structural and functional changes specifically in stellate ganglion neurons that project to the heart, but not in cells that project to brown adipose fat tissue.
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Affiliation(s)
- Madeleine S Barrett
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, Oregon, United States
| | - Temerity C Bauer
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, Oregon, United States
| | - Ming-Hua Li
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, Oregon, United States
| | - Deborah M Hegarty
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, Oregon, United States
| | - Clarissa M D Mota
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, Oregon, United States
| | - Chimezie J Amaefuna
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, Oregon, United States
| | - Susan L Ingram
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, Oregon, United States
| | - Beth A Habecker
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, Oregon, United States
| | - Sue A Aicher
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, Oregon, United States
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2
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Enes J, Haburčák M, Sona S, Gerard N, Mitchell AC, Fu W, Birren SJ. Satellite glial cells modulate cholinergic transmission between sympathetic neurons. PLoS One 2020; 15:e0218643. [PMID: 32017764 PMCID: PMC6999876 DOI: 10.1371/journal.pone.0218643] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 01/15/2020] [Indexed: 02/07/2023] Open
Abstract
Postganglionic sympathetic neurons and satellite glial cells are the two major cell types of the peripheral sympathetic ganglia. Sympathetic neurons project to and provide neural control of peripheral organs and have been implicated in human disorders ranging from cardiovascular disease to peripheral neuropathies. Here we show that satellite glia regulate synaptic activity of cultured postnatal sympathetic neurons, providing evidence for local ganglionic control of sympathetic drive. In addition to modulating neuron-to-neuron cholinergic neurotransmission, satellite glia promote synapse formation and contribute to neuronal survival. Examination of the cellular architecture of the rat sympathetic ganglia in vivo shows this regulation of neuronal properties takes place during a developmental period in which neuronal morphology and density are actively changing and satellite glia enwrap sympathetic neuronal somata. Cultured satellite glia make and release factors that promote neuronal activity and that can partially rescue the neurons from cell death following nerve growth factor deprivation. Thus, satellite glia play an early and ongoing role within the postnatal sympathetic ganglia, expanding our understanding of the contributions of local and target-derived factors in the regulation of sympathetic neuron function.
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Affiliation(s)
- Joana Enes
- Department of Biology, Brandeis University, Waltham, MA, United States of America
- Volen National Center for Complex Systems, Brandeis University, Waltham, MA, United States of America
| | - Marián Haburčák
- Department of Biology, Brandeis University, Waltham, MA, United States of America
- Volen National Center for Complex Systems, Brandeis University, Waltham, MA, United States of America
| | - Surbhi Sona
- Department of Biology, Brandeis University, Waltham, MA, United States of America
- Volen National Center for Complex Systems, Brandeis University, Waltham, MA, United States of America
| | - Nega Gerard
- Department of Biology, Brandeis University, Waltham, MA, United States of America
- Volen National Center for Complex Systems, Brandeis University, Waltham, MA, United States of America
| | - Alexander C. Mitchell
- Department of Biology, Brandeis University, Waltham, MA, United States of America
- Volen National Center for Complex Systems, Brandeis University, Waltham, MA, United States of America
| | - Wenqi Fu
- Department of Biology, Brandeis University, Waltham, MA, United States of America
- Volen National Center for Complex Systems, Brandeis University, Waltham, MA, United States of America
| | - Susan J. Birren
- Department of Biology, Brandeis University, Waltham, MA, United States of America
- Volen National Center for Complex Systems, Brandeis University, Waltham, MA, United States of America
- * E-mail:
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3
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Singh S, Sayers S, Walter JS, Thomas D, Dieter RS, Nee LM, Wurster RD. Hypertrophy of neurons within cardiac ganglia in human, canine, and rat heart failure: the potential role of nerve growth factor. J Am Heart Assoc 2013; 2:e000210. [PMID: 23959444 PMCID: PMC3828807 DOI: 10.1161/jaha.113.000210] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background Autonomic imbalances including parasympathetic withdrawal and sympathetic overactivity are cardinal features of heart failure regardless of etiology; however, mechanisms underlying these imbalances remain unknown. Animal model studies of heart and visceral organ hypertrophy predict that nerve growth factor levels should be elevated in heart failure; whether this is so in human heart failure, though, remains unclear. We tested the hypotheses that neurons in cardiac ganglia are hypertrophied in human, canine, and rat heart failure and that nerve growth factor, which we hypothesize is elevated in the failing heart, contributes to this neuronal hypertrophy. Methods and Results Somal morphology of neurons from human (579.54±14.34 versus 327.45±9.17 μm2; P<0.01) and canine hearts (767.80±18.37 versus 650.23±9.84 μm2; P<0.01) failing secondary to ischemia and neurons from spontaneously hypertensive rat hearts (327.98±3.15 versus 271.29±2.79 μm2; P<0.01) failing secondary to hypertension reveal significant hypertrophy of neurons in cardiac ganglia compared with controls. Western blot analysis shows that nerve growth factor levels in the explanted, failing human heart are 250% greater than levels in healthy donor hearts. Neurons from cardiac ganglia cultured with nerve growth factor are significantly larger and have greater dendritic arborization than neurons in control cultures. Conclusions Hypertrophied neurons are significantly less excitable than smaller ones; thus, hypertrophy of vagal postganglionic neurons in cardiac ganglia would help to explain the parasympathetic withdrawal that accompanies heart failure. Furthermore, our observations suggest that nerve growth factor, which is elevated in the failing human heart, causes hypertrophy of neurons in cardiac ganglia.
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Affiliation(s)
- Sanjay Singh
- Research Services, Hines VA Medical Center, Hines, IL
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4
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Osikowicz M, Longo G, Allard S, Cuello AC, Ribeiro-da-Silva A. Inhibition of endogenous NGF degradation induces mechanical allodynia and thermal hyperalgesia in rats. Mol Pain 2013; 9:37. [PMID: 23889761 PMCID: PMC3737061 DOI: 10.1186/1744-8069-9-37] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 07/24/2013] [Indexed: 12/27/2022] Open
Abstract
Background We have previously shown a sprouting of sympathetic fibers into the upper dermis of the skin following subcutaneous injection of complete Freund’s adjuvant (CFA) into the hindpaw. This sprouting correlated with an increase in pain-related sensitivity. We hypothesized that this sprouting and pain-related behavior were caused by an increase in nerve growth factor (NGF) levels. In this study, we investigated whether the inhibition of mature NGF degradation, using a matrix metalloproteinase 2 and 9 (MMP-2/9) inhibitor, was sufficient to reproduce a similar phenotype. Results Behavioral tests performed on male Sprague–Dawley rats at 1, 3, 7 and 14 days after intra-plantar MMP-2/9 inhibitor administration demonstrated that acute and chronic injections of the MMP-2/9 inhibitor induced sensitization, in a dose dependent manner, to mechanical, hot and cold stimuli as measured by von Frey filaments, Hargreaves and acetone tests, respectively. Moreover, the protein levels of mature NGF (mNGF) were increased, whereas the levels and enzymatic activity of matrix metalloproteinase 9 were reduced in the glabrous skin of the hind paw. MMP-2/9 inhibition also led to a robust sprouting of sympathetic fibers into the upper dermis but there were no changes in the density of peptidergic nociceptive afferents. Conclusions These findings indicate that localized MMP-2/9 inhibition provokes a pattern of sensitization and fiber sprouting comparable to that previously obtained following CFA injection. Accordingly, the modulation of endogenous NGF levels should be considered as a potential therapeutic target for the management of inflammatory pain associated with arthritis.
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5
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Ernsberger U. Role of neurotrophin signalling in the differentiation of neurons from dorsal root ganglia and sympathetic ganglia. Cell Tissue Res 2009; 336:349-84. [PMID: 19387688 DOI: 10.1007/s00441-009-0784-z] [Citation(s) in RCA: 142] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2008] [Accepted: 02/12/2009] [Indexed: 12/17/2022]
Abstract
Manipulation of neurotrophin (NT) signalling by administration or depletion of NTs, by transgenic overexpression or by deletion of genes coding for NTs and their receptors has demonstrated the importance of NT signalling for the survival and differentiation of neurons in sympathetic and dorsal root ganglia (DRG). Combination with mutation of the proapoptotic Bax gene allows the separation of survival and differentiation effects. These studies together with cell culture analysis suggest that NT signalling directly regulates the differentiation of neuron subpopulations and their integration into neural networks. The high-affinity NT receptors trkA, trkB and trkC are restricted to subpopulations of mature neurons, whereas their expression at early developmental stages largely overlaps. trkC is expressed throughout sympathetic ganglia and DRG early after ganglion formation but becomes restricted to small neuron subpopulations during embryogenesis when trkA is turned on. The temporal relationship between trkA and trkC expression is conserved between sympathetic ganglia and DRG. In DRG, NGF signalling is required not only for survival, but also for the differentiation of nociceptors. Expression of neuropeptides calcitonin gene-related peptide and substance P, which specify peptidergic nociceptors, depends on nerve growth factor (NGF) signalling. ret expression indicative of non-peptidergic nociceptors is also promoted by the NGF-signalling pathway. Regulation of TRP channels by NGF signalling might specify the temperature sensitivity of afferent neurons embryonically. The manipulation of NGF levels "tunes" heat sensitivity in nociceptors at postnatal and adult stages. Brain-derived neurotrophic factor signalling is required for subpopulations of DRG neurons that are not fully characterized; it affects mechanical sensitivity in slowly adapting, low-threshold mechanoreceptors and might involve the regulation of DEG/ENaC ion channels. NT3 signalling is required for the generation and survival of various DRG neuron classes, in particular proprioceptors. Its importance for peripheral projections and central connectivity of proprioceptors demonstrates the significance of NT signalling for integrating responsive neurons in neural networks. The molecular targets of NT3 signalling in proprioceptor differentiation remain to be characterized. In sympathetic ganglia, NGF signalling regulates dendritic development and axonal projections. Its role in the specification of other neuronal properties is less well analysed. In vitro analysis suggests the involvement of NT signalling in the choice between the noradrenergic and cholinergic transmitter phenotype, in the expression of various classes of ion channels and for target connectivity. In vivo analysis is required to show the degree to which NT signalling regulates these sympathetic neuron properties in developing embryos and postnatally.
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Affiliation(s)
- Uwe Ernsberger
- Interdisciplinary Center for Neurosciences (IZN), INF 307, University of Heidelberg, 69120, Heidelberg, Germany.
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6
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Abstract
The ability of the skin to serve as a protective shield against environmental challenges and as a sensitive detector and responder to thermal, chemical, and mechanical stimuli speaks to its exquisite design. A central feature of this design is the diverse array of neuronal afferents that convey and respond to sensory stimuli that the skin encounters. Cutaneous neuron development, form, and function are highly dependent on communication with the skin through its production of multiple growth factor proteins that modulate afferent development, maturation, and function. Production by the skin of neurotrophin growth factors and members of the glial cell line-derived neurotrophic factor family are particularly important for support of specific subsets of sensory neurons with unique phenotypic and functional properties. Although these proteins have central roles in afferent development and function, challenges remain in identifying specific molecular mechanisms of growth factor communication and understanding how activation of signaling pathways direct neuron differentiation and function under normal and pathological conditions.
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Affiliation(s)
- Kathryn M Albers
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA.
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7
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Geddes AJ, Angka HE, Davies KA, Kablar B. Subpopulations of motor and sensory neurons respond differently to brain-derived neurotrophic factor depending on the presence of the skeletal muscle. Dev Dyn 2006; 235:2175-84. [PMID: 16804896 DOI: 10.1002/dvdy.20877] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The aim of our study was to assess the ability of brain-derived neurotrophic factor (BDNF) to rescue motor and sensory neurons from programmed cell death. It is clearly demonstrated that the administration of a single injection of a putative neurotrophic factor to mouse embryos in utero on embryonic day (E) 14.5 is sufficient to significantly reduce the death of motor neurons when assessed on E18.5. However, the trophic requirements of somatic neurons have not been unequivocally determined in a mammalian species in vivo. Indeed, the unexpectedly high numbers of surviving neurons observed in neurotrophin and tyrosine kinase receptor knockout mice are probably the consequence of functional redundancy between the neurotrophins and their receptors. We studied spinal cord and facial motor nucleus neurons and proprioceptive neurons in the dorsal root ganglion and mesencephalic nucleus. The action of BDNF was assessed in wild-type fetuses to gain insight into its ability to rescue neurons from naturally occurring programmed cell death. In addition, we used Myf5(-/-):MyoD(-/-) embryos, which completely lack skeletal musculature, to assess the ability of BDNF to rescue neurons from excessively occurring programmed cell death. We found that BDNF differentially rescued neurons from naturally vs. excessively occurring cell death and that its ability to do so varied among neuronal subpopulations.
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Affiliation(s)
- Allison J Geddes
- Dalhousie University, Faculty of Medicine, Department of Anatomy and Neurobiology, Halifax, NS, Canada
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8
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Bierl MA, Isaacson LG. Increased NGF proforms in aged sympathetic neurons and their targets. Neurobiol Aging 2005; 28:122-34. [PMID: 16377033 DOI: 10.1016/j.neurobiolaging.2005.11.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2005] [Revised: 11/11/2005] [Accepted: 11/17/2005] [Indexed: 11/23/2022]
Abstract
Target-derived neurotrophins such as nerve growth factor (NGF) and neurotrophin-3 (NT-3) regulate sympathetic neuron survival. Here, NGF and NT-3 protein and transcript were examined in sympathetic neurons and targets in order to determine their role in age-related neuronal atrophy. One obvious alteration was a dramatic increase (up to 50-fold) in NGF protein forms, corresponding to proNGF-B, in the superior cervical ganglion (SCG) and targets where sympathetic innervation shows atrophy. In the iris, where sympathetic innervation is protected into old age, proNGF-B was decreased. Alterations in NGF transcript paralleled changes in NGF protein, albeit to a lesser degree. Though significantly increased in aged SCG, NT-3 protein, found primarily as the 'mature' form, showed only minor changes in most tissues, though NT-3 mRNA generally was decreased. In contrast, both NT-3 transcript and NT-3 precursors were increased in iris. The dramatic increases in proNGF, together with minimal changes in NT-3, suggest that alterations in NGF regulation may contribute to the loss of sympathetic innervation observed in many aged peripheral targets.
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Affiliation(s)
- Michael A Bierl
- Center for Neuroscience, Department of Zoology, Miami University, Oxford, OH 45056, USA
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9
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Carr VM, Sollars SI, Farbman AI. Neuronal cell death and population dynamics in the developing rat geniculate ganglion. Neuroscience 2005; 134:1301-8. [PMID: 16054764 DOI: 10.1016/j.neuroscience.2005.05.034] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2005] [Accepted: 05/19/2005] [Indexed: 11/24/2022]
Abstract
In contrast to many neuronal systems, the pattern of developmental neuronal degeneration in the rat geniculate ganglion has remained undefined. To address this issue sectioned geniculate ganglia from embryonic day 13 to postnatal day 3 have been examined using standard histological techniques, TdT-mediated dUTP-digoxigenin nick end labeling to verify apoptotic activity, bromo-deoxyuridine incorporation to monitor neuronal precursor proliferation, and anti-beta-neurotubulin III to verify the neuronal identity of pycnotic cells. Results summed from alternate (embryonic day 13) or every third (embryonic day 14-postnatal day 3) section show that neuronal degeneration occurs as early as embryonic day 13 (6.8% of neurons counted), well before geniculate innervation of lingual taste buds at embryonic day 16. A degenerative peak occurs at embryonic day 17 (9.5%) followed by a decline (1.7% at embryonic day 18) and leveling off (0.1%-0.2% at embryonic day 22-postnatal day 3). Thus, geniculate neuronal degenerative pattern includes both innervation-associated histogenetic and morphogenetic cell death. Corresponding counts of mean neuronal numbers in the sections showed a continual rise from embryonic day 13 through embryonic day 18 (approx. 330-760) followed by a slight decline at embryonic day 19 (to approx. 630) and then a final leveling off at 800-825 by embryonic day 20. This pattern differs from many other developing neural systems which show a major population crash during initial target contact. It likely reflects different but slightly overlapping neuronal precursor proliferation and degeneration patterns in multiple geniculate neuronal subpopulations.
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Affiliation(s)
- V McM Carr
- Department of Neurobiology and Physiology, Northwestern University, Evanston, IL 60208-3520, USA.
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10
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Guha U, Gomes WA, Samanta J, Gupta M, Rice FL, Kessler JA. Target-derived BMP signaling limits sensory neuron number and the extent of peripheral innervation in vivo. Development 2004; 131:1175-86. [PMID: 14973275 DOI: 10.1242/dev.01013] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The role of target-derived BMP signaling in development of sensory ganglia and the sensory innervation of the skin was examined in transgenic animals that overexpress either the BMP inhibitor noggin or BMP4 under the control of a keratin 14 (K14) promoter. Overexpression of noggin resulted in a significant increase in the number of neurons in the trigeminal and dorsal root ganglia. Conversely, overexpression of BMP4 resulted in a significant decrease in the number of dorsal root ganglion neurons. There was no significant change in proliferation of trigeminal ganglion neurons in the noggin transgenic animals, and neuron numbers did not undergo the normal developmental decrease between E12.5 and the adult, suggesting that programmed cell death was decreased in these animals. The increase in neuron numbers in the K14-noggin animals was followed by an extraordinary increase in the density of innervation in the skin and a marked change in the pattern of innervation by different types of fibers. Conversely, the density of innervation of the skin was decreased in the BMP4 overexpressing animals. Further Merkel cells and their innervation were increased in the K14-noggin mice and decreased in the K14-BMP4 mice. The changes in neuron numbers and the density of innervation were not accompanied by a change in the levels of neurotrophins in the skin. These findings indicate that the normal developmental decrease in neuron numbers in sensory ganglia depends upon BMP signaling, and that BMPs may limit both the final neuron number in sensory ganglia as well as the extent of innervation of targets. Coupled with prior observations, this suggests that BMP signaling may regulate the acquisition of dependence of neurons on neurotrophins for survival, as well as their dependence on target-derived neurotrophins for determining the density of innervation of the target.
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MESH Headings
- Animals
- Base Sequence
- Bone Morphogenetic Protein 4
- Bone Morphogenetic Proteins/genetics
- Bone Morphogenetic Proteins/metabolism
- Bone Morphogenetic Proteins/pharmacology
- Carrier Proteins
- Cell Count
- DNA, Complementary/genetics
- Ganglia, Spinal/embryology
- Ganglia, Spinal/growth & development
- Ganglia, Spinal/metabolism
- Gene Expression Regulation, Developmental
- In Situ Hybridization
- Keratin-14
- Keratins/genetics
- Mice
- Mice, Transgenic
- Nerve Growth Factor/pharmacology
- Neurons, Afferent/cytology
- Neurons, Afferent/drug effects
- Neurons, Afferent/metabolism
- Peripheral Nerves/embryology
- Peripheral Nerves/growth & development
- Peripheral Nerves/metabolism
- Promoter Regions, Genetic
- Proteins/genetics
- Proteins/metabolism
- Signal Transduction
- Skin/innervation
- Trigeminal Ganglion/embryology
- Trigeminal Ganglion/growth & development
- Trigeminal Ganglion/metabolism
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Affiliation(s)
- Udayan Guha
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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11
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Harrison SMW, Davis BM, Nishimura M, Albers KM, Jones ME, Phillips HS. Rescue of NGF-deficient mice I: transgenic expression of NGF in skin rescues mice lacking endogenous NGF. ACTA ACUST UNITED AC 2004; 122:116-25. [PMID: 15010204 DOI: 10.1016/j.molbrainres.2003.12.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/16/2003] [Indexed: 01/15/2023]
Abstract
Mice lacking a functional NGF gene (ngf-/- mice) have less than one third of the normal complement of sensory neurons, few sympathetic postganglionic neurons and die shortly after birth. We report here that transgenic expression of NGF under control of the K14 keratin promoter can rescue some elements of the peripheral nervous system and restore normal growth and viability to ngf-/- mice. While hybrid transgenic-ngf-/- mice (ngfTKOs) displayed marginal rescue of trigeminal ganglion neurons, the percentage of CGRP-positive neurons was restored to normal. Restoration of CGRP-positive terminals in skin and spinal cord was also found and accompanied by recovery of behavioral responses to noxious stimuli. ngfTKO mice displayed a normal number of superior cervical ganglion neurons and recovery of sympathetic innervation of skin. These results demonstrate that substitution of a functional NGF locus by a transgene directing expression largely to skin can result in normal growth and viability. Thus, the most vital functions of NGF are not dependent on faithful recapitulation of the normal spatiotemporal pattern of gene expression.
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MESH Headings
- Animals
- Cell Survival/genetics
- Female
- Ganglia, Sympathetic/abnormalities
- Ganglia, Sympathetic/cytology
- Ganglia, Sympathetic/growth & development
- Gene Expression Regulation, Developmental/genetics
- Genetic Therapy/methods
- Male
- Mice
- Mice, Knockout
- Mice, Transgenic
- Nerve Growth Factor/biosynthesis
- Nerve Growth Factor/deficiency
- Nerve Growth Factor/genetics
- Neurons, Afferent/cytology
- Neurons, Afferent/metabolism
- Nociceptors/abnormalities
- Nociceptors/cytology
- Nociceptors/growth & development
- Pain/genetics
- Pain/metabolism
- Peripheral Nervous System/abnormalities
- Peripheral Nervous System/cytology
- Peripheral Nervous System/growth & development
- Sensory Receptor Cells/abnormalities
- Sensory Receptor Cells/cytology
- Sensory Receptor Cells/growth & development
- Skin/growth & development
- Skin/innervation
- Skin/metabolism
- Skin Abnormalities/genetics
- Skin Abnormalities/metabolism
- Sympathetic Fibers, Postganglionic/abnormalities
- Sympathetic Fibers, Postganglionic/cytology
- Sympathetic Fibers, Postganglionic/growth & development
- Transgenes/genetics
- Trigeminal Ganglion/abnormalities
- Trigeminal Ganglion/cytology
- Trigeminal Ganglion/growth & development
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Affiliation(s)
- Susan M W Harrison
- School of Biological Sciences, University of Kentucky, Lexington, KY 40506, USA
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12
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Glial cell line-derived neurotrophic factor is a survival factor for isolectin B4-positive, but not vanilloid receptor 1-positive, neurons in the mouse. J Neurosci 2002. [PMID: 12019325 DOI: 10.1523/jneurosci.22-10-04057.2002] [Citation(s) in RCA: 154] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Most, if not all, nociceptor sensory neurons are dependent on nerve growth factor (NGF) during early embryonic development. A large subpopulation of these sensory neurons loses NGF dependency between embryonic day 16 and postnatal day 14 and become responsive to glial cell line-derived growth factor (GDNF), a member of the transforming growth factor beta (TGF-beta) family. To examine the survival and phenotypic effects of GDNF on sensory neurons in vivo, we generated transgenic mice that overexpress GDNF in the skin. GDNF-overexpresser mice had increased numbers of small unmyelinated sensory neurons that express the tyrosine kinase receptor Ret and bind the plant isolectin B4 (IB4). Surprisingly, in wild-type and transgenic mice, few ( approximately 2%) IB4-positive neurons expressed the vanilloid receptor VR1, a heat-sensitive receptor expressed by many IB4-positive neurons of the rat. Thus, in mouse, GDNF-dependent IB4-positive neurons must use a non-VR1 heat receptor. In addition, the behavior of GDNF-overexpresser animals to noxious heat or mechanical stimuli was indistinguishable from wild-type animals, indicating that, on a behavioral level, peripherally applied GDNF does not alter the sensitivity of the somatosensory system.
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13
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Figueiredo HF, Davis BM, Albers KM. Skin-derived nerve growth factor blocks programmed cell death in the trigeminal ganglia but does not enhance neuron proliferation. Mech Dev 2001; 109:205-14. [PMID: 11731234 DOI: 10.1016/s0925-4773(01)00525-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Development of the cutaneous sensory nervous system is dependent on the production of neurotrophic factors, such as nerve growth factor (NGF), by the skin. Limited synthesis of NGF in developing skin is thought to underlie programmed cell death and cause a 50% neuronal loss. This loss does not occur in transgenic mice that overexpress NGF in the skin, which have double the number of neurons (J. Neurosci. 14 (1994) 1422). To determine whether increased NGF blocks neuronal death and/or increases neuronal precursor replication, we analyzed the trigeminal ganglia at embryonic days E12.5, E14.5 and E16.5 using transferase-mediated dUTP nick-end labeling (TUNEL) and bromodeoxyuridine labeling. Results show that excess target-derived NGF causes a major decrease in the percent of TUNEL-labeled neurons without affecting the percent of replicating neurons. Analysis of RNA and protein expression suggests this block in cell death is mediated via the anti-apoptotic protein bcl-2.
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Affiliation(s)
- H F Figueiredo
- Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536-0298, USA
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Fried K, Bongenhielm U, Boissonade FM, Robinson PP. Nerve injury-induced pain in the trigeminal system. Neuroscientist 2001; 7:155-65. [PMID: 11496926 DOI: 10.1177/107385840100700210] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
This article reviews some recent findings on peripheral mechanisms related to the development of oro-facial pain after trigeminal nerve injury. Chronic injury-induced oro-facial pain is not in itself a life-threatening condition, but patients suffering from this disorder undoubtedly have a reduced quality of life. The vast majority of the work on pain mechanisms has been carried out in spinal nerve systems. Those studies have provided great insight into mechanisms of neuropathic spinal pain, and much of the data from them is obviously relevant to studies of trigeminal pain. However, it is now clear that the pathophysiology of the trigeminal nerve (a cranial nerve) is in many ways different to that found in spinal nerves. Whereas some of the changes seen in animal models of trigeminal nerve injury mimic those occurring after spinal nerve injury (e.g., the development of spontaneous activity from the damaged axons), others are different, such as the time-course of the spontaneous activity, some of the neuropeptide changes in the trigeminal ganglion, and the lack of sprouting of sympathetic terminals in the ganglion. Recent findings provide new insights that help our understanding of the etiology of chronic injury-induced oro-facial pain. Future investigations will hopefully explain how data gained from these studies relate to clinical pain experience in man and should enable the rapid development of new therapeutic regimes.
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Affiliation(s)
- K Fried
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.
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15
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Harrison SM, Jones ME, Uecker S, Albers KM, Kudrycki KE, Davis BM. Levels of nerve growth factor and neurotrophin-3 are affected differentially by the presence of p75 in sympathetic neurons in vivo. J Comp Neurol 2000; 424:99-110. [PMID: 10888742 DOI: 10.1002/1096-9861(20000814)424:1<99::aid-cne8>3.0.co;2-j] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The development and survival of sympathetic neurons is critically dependent on the related neurotrophic factors nerve growth factor (NGF) and neurotrophin-3 (NT3), the actions of which must be executed appropriately despite spatial and temporal overlaps in their activities. The tyrosine receptor kinases, trkA and trkC, are the cognate receptors for NGF and NT3, respectively. The p75 neurotrophin receptor has been implicated in neurotrophin binding and signaling for both NGF and NT3. In this study, the authors used mice that overexpressed NGF (NGF-OE) or NT3 (NT3-OE) in skin and mice that lacked p75 (p75(-/-)) to understand the dynamics of sympathetic neuron response to each neurotrophin and to address the role of p75. NGF and NT3 were measured in sympathetic ganglia and skin (a major target of sympathetic neurons) by using the enzyme-linked immunosorbent assay (ELISA) technique. A three- to four-fold increase in skin NT3 was seen in both NT3-OE and p75(-/-) mice. Moreover, both mouse lines exhibited a three-fold increase in ganglionic NT3. However, the increase in ganglionic NT3 was accompanied by a decrease in ganglionic NGF in p75(-/-) mice but not in NT3-OE mice. This indicated that p75 plays an important role in determining the level of NGF within sympathetic neurons. In NGF-OE mice, the overexpression of NGF was correlated with increased ganglionic NGF and increased ganglionic expression of p75 mRNA. In addition, in NGF-OE mice, ganglionic trkC expression was decreased, as was the amount of NT3 present within sympathetic ganglia. These results indicate that the level of p75 is integral in determining the level of sympathetic NGF and that NGF competes with NT3 by increasing the expression of p75 and decreasing the expression of trkC.
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MESH Headings
- Animals
- Cell Count
- Ganglia, Sympathetic/cytology
- Ganglia, Sympathetic/metabolism
- Mice
- Mice, Knockout/genetics
- Mice, Transgenic/genetics
- Nerve Growth Factor/genetics
- Nerve Growth Factor/metabolism
- Neurons/cytology
- Neurons/metabolism
- Neurotrophin 3/genetics
- Neurotrophin 3/metabolism
- RNA, Messenger/metabolism
- Receptor, Nerve Growth Factor/genetics
- Receptor, Nerve Growth Factor/metabolism
- Receptor, trkA/genetics
- Receptor, trkC/genetics
- Receptors, Nerve Growth Factor/metabolism
- Skin/metabolism
- Tissue Distribution
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Affiliation(s)
- S M Harrison
- Department of Anatomy and Neurobiology, University of Kentucky College of Medicine, Lexington, Kentucky 40536, USA
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16
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Abstract
The occurrence of neuronal death during development is well documented for some neuronal populations, such as motoneurones and dorsal root ganglion cells, whose connecting pathways are clearly defined. Cell survival is thought to be regulated largely by target and input connections, a process that serves to match the size of synaptically linked neuronal populations. Far less is known about interneurones. It is assumed that most interneurone populations are excluded from this process because their connections are more diffuse. Recent studies on the rat spinal cord have indicated that interneurone death does occur, both naturally during development and induced following peripheral nerve injury. Here the evidence for spinal interneurone death is reviewed and the factors influencing it are discussed. There are many functional types of interneurones in the spinal cord that may differ in vulnerability to cell death, but it is concluded that for most spinal interneurones the traditional view of target regulation is unlikely. Instead it is proposed that developmental interneurone death in the spinal cord forms part of a plastic response to altered sensory activation rather than a size-matching exercise. There is also emerging evidence that interneurone death may play a more direct role in some neurodegenerative diseases than hitherto considered.
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Affiliation(s)
- M B Lowrie
- Division of Biomedical Sciences, Imperial College School of Medicine, London, UK.
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17
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Overexpression of nerve growth factor in skin selectively affects the survival and functional properties of nociceptors. J Neurosci 1999. [PMID: 10493751 DOI: 10.1523/jneurosci.19-19-08509.1999] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Mice that overexpress nerve growth factor (NGF-OE) in the skin have double the normal number of cutaneous sensory neurons, have increased innervation of the skin and spinal cord, and are hyperalgesic. Here, we have asked whether the increased cutaneous NGF level results in a selective survival of only certain functional types of neurons and whether it changes the properties of cutaneous neurons. Using electron microscopy, we show that the number of both myelinated and unmyelinated nociceptors increases substantially in NGF-OE mice by a factor of 3.3 and 1.5, respectively. Using extracellular recordings from single units, we demonstrate that large myelinated (Abeta) fibers are unchanged in prevalence and receptive properties. In contrast, among thin myelinated (Adelta) fibers, the percentage of nociceptors increased from a normal 65 to 97%, consistent with a selective survival of nociceptors during embryogenesis. These afferents showed a twofold increase in their mechanical responsiveness, but their heat responsiveness remained normal. Among unmyelinated (C) fibers, there was a profound increase in the percentage of heat responsive neurons from a normal 42 to 96%. This change cannot be accounted for by a selective survival of heat-sensitive neurons. Unmyelinated nociceptors increased fourfold in their thermal responsiveness but decreased in mechanical responsiveness. Therefore, target-derived NGF selectively rescues nociceptors during the period of programmed cell death with different efficacy for thin myelinated or unmyelinated fibers. NGF also affects the response to noxious heat or mechanical stimuli in each group differently, implying specific regulations of transduction processes rather than general changes of excitability.
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18
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Morris JL, Zhu BS, Gibbins IL, Blessing WW. Subpopulations of sympathetic neurons project to specific vascular targets in the pinna of the rabbit ear. J Comp Neurol 1999. [DOI: 10.1002/(sici)1096-9861(19990913)412:1<147::aid-cne11>3.0.co;2-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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19
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Bongenhielm U, Boissonade FM, Westermark A, Robinson PP, Fried K. Sympathetic nerve sprouting fails to occur in the trigeminal ganglion after peripheral nerve injury in the rat. Pain 1999; 82:283-288. [PMID: 10488679 DOI: 10.1016/s0304-3959(99)00064-0] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Peripheral nerve injury induces sprouting of sympathetic nerve fibers in dorsal root ganglia after spinal nerve injury. In the present study, we sought to determine the extent of intraganglionic noradrenergic sprouting in the trigeminal system. The inferior alveolar nerve, a major branch of the mandibular division, or the infraorbital nerve of the maxillary division was either ligated or chronically constricted in Sprague-Dawley rats and recovery permitted for either 2-3 or 6-9 weeks. In some animals both nerves were injured. Using immunohistochemistry with tyrosine hydroxylase antibodies, we found no signs of sympathetic nerve fiber sprouting in the trigeminal ganglion after injury. In contrast, sciatic nerve injury in rat littermates induced a widespread autonomic nerve outgrowth in affected DRGs. Thus, sensory ganglion sympathetic nerve sprouting does not seem to be a general outcome of PNS injury, but is restricted to certain specific locations. Sympathetic nerve fiber networks that surround primary sensory neurons have been suggested to form a structural basis for interactions between the sympathetic and sensory nervous systems after PNS injury. Such interactions, sometimes resulting in paraesthesia or dysaesthesia in patients, appear to be less common in territories innervated by the trigeminal nerve than in spinal nerve regions. The lack of injury-induced intraganglionic sympathetic sprouting in the trigeminal ganglion may help to explain this observation.
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Affiliation(s)
- U Bongenhielm
- Dept of Neuroscience, Karolinska Institutet, S-171 77 Stockholm, Sweden Department of Oral and Maxillofacial Surgery, Huddinge Hospital, Karolinska Institute S-18146 Huddinge, Sweden Department of Oral and Maxillofacial Surgery, School of Clinical Dentistry, University of Sheffield, Sheffield, S10 2TA, UK Department of Oral and Maxillofacial Surgery, Karolinska Hospital, S-171 76 Stockholm, Sweden
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20
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Overexpression of brain-derived neurotrophic factor enhances sensory innervation and selectively increases neuron number. J Neurosci 1999. [PMID: 10407031 DOI: 10.1523/jneurosci.19-14-05919.1999] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Target-derived neurotrophin growth factors have significant effects on the development and maintenance of the mammalian somatosensory system. Studies of transgenic mice that overexpress neurotrophins NGF and neurotrophin 3 (NT-3) at high levels in skin have shown increased sensory neuron number and enhanced innervation of specific sensory ending types. The effects of two other members of this family, BDNF and NT-4, on sensory neuron development are less clear. This study examined the role of brain-derived neurotrophic factor (BDNF) using transgenic mice that overexpress BDNF in epithelial target tissues of sensory neurons. BDNF transgenic mice had an increase in peripheral innervation density and showed selective effects on neuron survival. Neuron number in trigeminal ganglia, DRG, and SCG were unchanged, although a 38% increase in neurons comprising the placode-derived nodose-petrosal complex occurred. BDNF transgenic skin showed notable enhancement of innervation to hair follicles as detected by PGP9.5 immunolabeling. In nonhairy plantar skin, Meissner corpuscle sensory endings were larger, and the number of Merkel cells with associated innervation was increased. In trigeminal ganglia, neurons expressing trkB receptor were increased threefold, whereas trkA-positive neurons doubled. Analysis of trkB by Northern, reverse transcription-PCR, and Western assays indicated a modest increase in the expression of the T1 truncated receptor and preferential distribution to the periphery. These data indicate that skin-derived BDNF does not enhance survival of cutaneous sensory neurons, although it does promote neurite innervation of specific sites and sensory end organs of the skin.
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21
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Coome GE, Kawaja MD. Prolonged exposure to elevated levels of endogenous nerve growth factor affects the morphological and neurochemical features of sympathetic neurons of postnatal and adult mice. Neuroscience 1999; 90:941-55. [PMID: 10218794 DOI: 10.1016/s0306-4522(98)00499-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
It is well documented that acute increases of target-derived nerve growth factor affect the morphological and neurochemical features of post-ganglionic sympathetic neurons. It has yet to be determined, however, whether similar changes are still evident after prolonged exposure to increased levels of endogenous nerve growth factor. Using a transgenic line of mice which overexpresses nerve growth factor in the brain commencing after the first week of postnatal life and continuing into adulthood, we have shown previously that sympathetic axons sprout into the nerve growth factor-rich cerebellum of these animals; no such axons are seen in the cerebellum of age-matched wild type animals. The aim of this study was to examine and characterize the effects of chronically elevated levels of endogenous nerve growth factor on sympathetic neurons of the superior cervical ganglion. In comparison to adult wild type mice, adult transgenic animals possessed hypertrophied ganglia which displayed both an increase in sympathetic somal size and a decrease in their density. At the electron microscope level, sympathetic somata of the adult transgenic animals had numerous electron-dense lysosome-like structures in the cytoplasm, as compared to that seen in the sympathetic somata of adult wild type animals. Immunodetection of nerve growth factor in the sympathetic somata revealed that the staining intensity in postnatal (day 28) transgenic mice was greater than that in age-matched wild type mice. By adulthood, however, such differences in the intensities of nerve growth factor immunostaining were no longer evident. In situ hybridization analyses of trkA receptor messenger RNA revealed that levels of expression among somata of similar sizes were comparable between the transgenic and wild type neuronal populations of both postnatal day 28 and adult animals. A small subpopulation of sympathetic somata in postnatal transgenic mice displayed a marked increase in p75NTR messenger RNA expression in comparison to somata of a similar size in age-matched wild type animals. By adulthood, the proportion of sympathetic somata in the transgenic animals possessing elevated levels of p75NTR messenger RNA expression had increased. These results reveal that chronically elevated levels of endogenous nerve growth factor in the postnatal and adult mouse brain can induce both structural and neurochemical remodelling of sympathetic neurons. The preferential increase in p75NTR messenger RNA expression among sympathetic somata of transgenic mice may be required for their growth of collateral axons into the nerve growth factor-rich cerebellum during postnatal development and may facilitate the increased immunodetection of nerve growth factor on these aberrant sympathetic axons in adult transgenic animals.
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Affiliation(s)
- G E Coome
- Department of Anatomy and Cell Biology, Queen's University, Kingston, Ontario, Canada
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22
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Abstract
The highly disagreeable sensation of pain results from an extraordinarily complex and interactive series of mechanisms integrated at all levels of the neuroaxis, from the periphery, via the dorsal horn to higher cerebral structures. Pain is usually elicited by the activation of specific nociceptors ('nociceptive pain'). However, it may also result from injury to sensory fibres, or from damage to the CNS itself ('neuropathic pain'). Although acute and subchronic, nociceptive pain fulfils a warning role, chronic and/or severe nociceptive and neuropathic pain is maladaptive. Recent years have seen a progressive unravelling of the neuroanatomical circuits and cellular mechanisms underlying the induction of pain. In addition to familiar inflammatory mediators, such as prostaglandins and bradykinin, potentially-important, pronociceptive roles have been proposed for a variety of 'exotic' species, including protons, ATP, cytokines, neurotrophins (growth factors) and nitric oxide. Further, both in the periphery and in the CNS, non-neuronal glial and immunecompetent cells have been shown to play a modulatory role in the response to inflammation and injury, and in processes modifying nociception. In the dorsal horn of the spinal cord, wherein the primary processing of nociceptive information occurs, N-methyl-D-aspartate receptors are activated by glutamate released from nocisponsive afferent fibres. Their activation plays a key role in the induction of neuronal sensitization, a process underlying prolonged painful states. In addition, upon peripheral nerve injury, a reduction of inhibitory interneurone tone in the dorsal horn exacerbates sensitized states and further enhance nociception. As concerns the transfer of nociceptive information to the brain, several pathways other than the classical spinothalamic tract are of importance: for example, the postsynaptic dorsal column pathway. In discussing the roles of supraspinal structures in pain sensation, differences between its 'discriminative-sensory' and 'affective-cognitive' dimensions should be emphasized. The purpose of the present article is to provide a global account of mechanisms involved in the induction of pain. Particular attention is focused on cellular aspects and on the consequences of peripheral nerve injury. In the first part of the review, neuronal pathways for the transmission of nociceptive information from peripheral nerve terminals to the dorsal horn, and therefrom to higher centres, are outlined. This neuronal framework is then exploited for a consideration of peripheral, spinal and supraspinal mechanisms involved in the induction of pain by stimulation of peripheral nociceptors, by peripheral nerve injury and by damage to the CNS itself. Finally, a hypothesis is forwarded that neurotrophins may play an important role in central, adaptive mechanisms modulating nociception. An improved understanding of the origins of pain should facilitate the development of novel strategies for its more effective treatment.
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Affiliation(s)
- M J Millan
- Institut de Recherches Servier, Psychopharmacology Department, Paris, France
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23
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Schicho R, Kanai Y, Ishikawa T, Skofitsch G, Donnerer J. Involvement of NGF in the induction of increased noradrenergic innervation of the ureter in neonatally capsaicin-treated rats. JOURNAL OF THE AUTONOMIC NERVOUS SYSTEM 1998; 73:46-53. [PMID: 9808370 DOI: 10.1016/s0165-1838(98)00125-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Neonatal denervation of primary afferents with capsaicin leads to increased sympathetic innervation of the rat ureter. In the present study the development and the immunohistochemical characterization of this sympathetic hyperinnervation as well as the specific involvement of nerve growth factor (NGF) was investigated. Noradrenaline levels were found elevated in neonatally capsaicin-treated rats by 2 weeks of age and remained at that high level into adulthood. Injections of an anti-NGF antiserum during postnatal days (PN) PN 8-14, PN 13-19 or during PN 17-23 counteracted the capsaicin effect and reduced noradrenaline towards control levels. Immunohistochemical localization of tyrosine hydroxylase (TH), a marker for sympathetic nerve fibres, revealed that the capsaicin-induced hyperinnervation was mainly represented by fibres in deeper muscle layers and to a smaller extent by fibres in the submucosa. In control animals and in rats treated with capsaicin and anti-NGF antiserum fibres were mainly distributed in the adventitia and in the outer part of the smooth muscle layer. These results show that NGF is responsible for the development of an increased noradrenergic innervation in the rat ureter after neonatal capsaicin treatment.
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Affiliation(s)
- R Schicho
- Department of Experimental and Clinical Pharmacology, University of Graz, Austria
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24
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Kawaja MD, Walsh GS, Tovich PR, Julien JP. Effects of elevated levels of nerve growth factor on the septohippocampal system in transgenic mice. Eur J Neurosci 1998; 10:2207-16. [PMID: 9749749 DOI: 10.1046/j.1460-9568.1998.00228.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Elevating target-derived levels of nerve growth factor (NGF) in peripheral organs of postnatal mammals is known to enhance the survival of postganglionic sympathetic neurons and to promote the terminal arborization of sympathetic axons within such NGF-rich target tissues. Although increasing levels of NGF in the central nervous system can ameliorate cholinergic function of damaged and aged neurons of the medial septum, it remains undetermined whether the postnatal development of this neuronal population and their projections that innervate the hippocampus are likewise affected by elevated levels of target-derived NGF. To address this question, the cholinergic septohippocampal pathway was examined in adult transgenic mice which display elevated levels of NGF protein production in the dorsal hippocampus during postnatal development. Adult transgenic mice possessed a cholinergic population of septal neurons approximately 15% larger than that seen in age-matched control animals. Despite increased numbers of cholinergic septal neurons, as well as elevated levels of hippocampal NGF, the density of cholinergic septal axons in the outer molecular layer of the hippocampal dentate gyrus of adult transgenic animals was comparable with that found in wild-type controls. These results reveal that elevating levels of target-derived NGF during postnatal development can increase the population size of the cholinergic septal neurons but does not alter their pattern of afferent innervation in the hippocampus of adult mice.
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Affiliation(s)
- M D Kawaja
- Department of Anatomy and Cell Biology, Queen's University, Kingston, Ontario, Canada.
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25
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Guidry G, Landis SC, Davis BM, Albers KM. Overexpression of nerve growth factor in epidermis disrupts the distribution and properties of sympathetic innervation in footpads. J Comp Neurol 1998; 393:231-43. [PMID: 9548699 DOI: 10.1002/(sici)1096-9861(19980406)393:2<231::aid-cne7>3.0.co;2-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Sympathetic and sensory neurons form distinct axonal arborizations in several peripheral targets. The developmental mechanisms responsible for partitioning sympathetic and sensory axons between potential target tissues are poorly understood. We have used rodent footpads to study this process because three populations of peripheral axons innervate topographically segregated targets in the footpad; cholinergic sympathetic axons innervate sweat glands, noradrenergic sympathetic axons innervate blood vessels, and sensory axons form a plexus at the epidermal/dermal junction. To examine how nerve growth factor (NGF), a trophic and survival factor for sympathetic and some sensory neurons, may contribute to the generation of the patterned distribution of axons among targets, we studied transgenic mice (K14-NGF mice) in which NGF expression was significantly increased in the epidermis. Whereas the temporal sequence in which sensory and sympathetic fibers arrived in the footpad was not affected, the normal partitioning of axons between target tissues was disrupted. The two sympathetic targets in footpads, sweat glands, and blood vessels lacked substantial innervation and instead a dense plexus of catecholaminergic sympathetic fibers was found commingled with sensory fibers in the dermis. Those sympathetic fibers present in sweat glands expressed an abnormal dual catecholaminergic/cholinergic phenotype. Our findings indicate that overexpression of NGF in skin interferes with the segregation of sensory and sympathetic axonal arbors and suggests a role for target-derived NGF in the establishment of distinct axonal territories. Our data also suggest that by determining where axon arbors form, NGF can indirectly influence the phenotypic properties of sympathetic neurons.
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Affiliation(s)
- G Guidry
- Department of Neurosciences, Case Western Reserve University, Cleveland, Ohio 44106, USA
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26
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Carlson SL, Johnson S, Parrish ME, Cass WA. Development of immune hyperinnervation in NGF-transgenic mice. Exp Neurol 1998; 149:209-20. [PMID: 9454630 DOI: 10.1006/exnr.1997.6711] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Sympathetic innervation of lymphoid tissues is localized to specific tissue compartments, but little is known of the "factors" that are important in establishing this pattern during development. Numerous studies have shown interactions of nerve growth factor (NGF) with the immune system, which may include modulation of immune innervation. We previously have shown that NGF transgenic mice, which overexpress NGF in skin and not immune tissues, have a dramatic hyperinnervation of splenic marginal zone and peripheral lymph node medulla and capsule. The purpose of the current studies was to determine if the presence of elevated NGF would alter immune system development and the process of sympathetic ingrowth. The results show that the splenic innervation in NGF transgenics gradually diverged from controls during the first two postnatal weeks, with the greatest change occurring between postnatal days 13 and 16 when the splenic organization was reaching the adult pattern. In contrast, the peripheral lymph nodes were hyperinnervated at an earlier age. mesenteric lymph nodes never diverged from the normal pattern. NGF levels in transgenic spleen were much higher than controls at postnatal days 1 and 2, when little innervation was present, and declined as the tissue matured, possibly because of NGF uptake by the ingrowing sympathetic fibers. This suggests that immune tissues are capable of concentrating NGF, which in turn may modulate the level of innervation by the sympathetic nervous system.
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Affiliation(s)
- S L Carlson
- Department of Anatomy and Neurobiology, University of Kentucky Medical Center, Lexington 40536-0084, USA
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27
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Davis BM, Fundin BT, Albers KM, Goodness TP, Cronk KM, Rice FL. Overexpression of nerve growth factor in skin causes preferential increases among innervation to specific sensory targets. J Comp Neurol 1997; 387:489-506. [PMID: 9373009 DOI: 10.1002/(sici)1096-9861(19971103)387:4<489::aid-cne2>3.0.co;2-z] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The impact of increased levels of skin-derived nerve growth factor (NGF) neurotrophin on sensory and sympathetic innervation to the mouse mystacial pad and postero-orbital vibrissae was determined. Consistent with an approximate doubling of neuron number in trigeminal and superior cervical ganglia, many components of the sensory and sympathetic innervation were substantially enhanced. Although the increased number of neurons raised the possibility that all types of innervation were increased, immunohistochemical analysis indicated that enhanced NGF production had a differential effect upon sensory innervation, primarily increasing unmyelinated innervation. This increased innervation occurred in specific locations known to be innervated by small, unmyelinated fibers, suggesting that NGF modulated sensory innervation density, but not targeting. In contrast, sympathetic innervation was not only increased but also was distributed to some aberrant locations. In the intervibrissal fur of the mystacial pad, both the number of sensory axons and branches appeared increased, whereas in vibrissal follicle sinus complexes, only branching increased. In some areas, sensory ending density was lower than expected based upon the size of the source nerve bundles suggesting that many axons and branches were surviving but failing to form functional endings. Furthermore, the immunochemical profile of innervation was altered in some sensory populations as demonstrated by the coexistence of RT-97 neurofilament labeling in calcitonin gene-related peptide (CGRP) positive axons, by the loss of substance P colocalization in some CGRP axons, and by an absence of neuropeptide Y labeling in tyrosine hydroxylase positive sympathetic axons. Collectively, these results indicate that the NGF mediated increase in neuron number may be selective for particular sets of innervation and that increases among some populations may result from phenotypic switching.
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Affiliation(s)
- B M Davis
- Department of Anatomy and Neurobiology, University of Kentucky College of Medicine, Lexington 40536-0084, USA
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