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Meehan SD, Abdelrahman L, Arcuri J, Park KK, Samarah M, Bhattacharya SK. Proteomics and systems biology in optic nerve regeneration. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2021; 127:249-270. [PMID: 34340769 DOI: 10.1016/bs.apcsb.2021.03.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We present an overview of current state of proteomic approaches as applied to optic nerve regeneration in the historical context of nerve regeneration particularly central nervous system neuronal regeneration. We present outlook pertaining to the optic nerve regeneration proteomics that the latter can extrapolate information from multi-systems level investigations. We present an account of the current need of systems level standardization for comparison of proteome from various models and across different pharmacological or biophysical treatments that promote adult neuron regeneration. We briefly overview the need for deriving knowledge from proteomics and integrating with other omics to obtain greater biological insight into process of adult neuron regeneration in the optic nerve and its potential applicability to other central nervous system neuron regeneration.
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Affiliation(s)
- Sean D Meehan
- Molecular and Cellular Pharmacology Graduate Program, University of Miami, Miami, FL, United States; Miami Integrative Metabolomics Research Center, University of Miami, Miami, FL, United States
| | - Leila Abdelrahman
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, United States; Department of Electrical and Computer Engineering, University of Miami, Miami, FL, United States
| | - Jennifer Arcuri
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, United States; Molecular and Cellular Pharmacology Graduate Program, University of Miami, Miami, FL, United States; Miami Integrative Metabolomics Research Center, University of Miami, Miami, FL, United States
| | - Kevin K Park
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, United States; Miami Integrative Metabolomics Research Center, University of Miami, Miami, FL, United States; Miami Project to Cure Paralysis, University of Miami, Miami, FL, United States
| | | | - Sanjoy K Bhattacharya
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, United States; Molecular and Cellular Pharmacology Graduate Program, University of Miami, Miami, FL, United States; Miami Integrative Metabolomics Research Center, University of Miami, Miami, FL, United States.
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Claes M, De Groef L, Moons L. Target-Derived Neurotrophic Factor Deprivation Puts Retinal Ganglion Cells on Death Row: Cold Hard Evidence and Caveats. Int J Mol Sci 2019; 20:E4314. [PMID: 31484425 PMCID: PMC6747494 DOI: 10.3390/ijms20174314] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 08/28/2019] [Accepted: 08/30/2019] [Indexed: 12/14/2022] Open
Abstract
Glaucoma and other optic neuropathies are characterized by axonal transport deficits. Axonal cargo travels back and forth between the soma and the axon terminus, a mechanism ensuring homeostasis and the viability of a neuron. An example of vital molecules in the axonal cargo are neurotrophic factors (NTFs). Hindered retrograde transport can cause a scarcity of those factors in the retina, which in turn can tilt the fate of retinal ganglion cells (RGCs) towards apoptosis. This postulation is one of the most widely recognized theories to explain RGC death in the disease progression of glaucoma and is known as the NTF deprivation theory. For several decades, research has been focused on the use of NTFs as a novel neuroprotective glaucoma treatment. Until now, results in animal models have been promising, but translation to the clinic has been highly disappointing. Are we lacking important knowledge to lever NTF therapies towards the therapeutic armamentarium? Or did we get the wrong end of the stick regarding the NTF deprivation theory? In this review, we will tackle the existing evidence and caveats advocating for and against the target-derived NTF deprivation theory in glaucoma, whilst digging into associated therapy efforts.
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Affiliation(s)
- Marie Claes
- Laboratory of Neural Circuit Development and Regeneration, Department of Biology, KU Leuven, 3000 Leuven, Belgium
| | - Lies De Groef
- Laboratory of Neural Circuit Development and Regeneration, Department of Biology, KU Leuven, 3000 Leuven, Belgium
| | - Lieve Moons
- Laboratory of Neural Circuit Development and Regeneration, Department of Biology, KU Leuven, 3000 Leuven, Belgium.
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Park KK, Luo X, Mooney SJ, Yungher BJ, Belin S, Wang C, Holmes MM, He Z. Retinal ganglion cell survival and axon regeneration after optic nerve injury in naked mole-rats. J Comp Neurol 2016; 525:380-388. [PMID: 27350178 DOI: 10.1002/cne.24070] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2016] [Revised: 06/23/2016] [Accepted: 06/24/2016] [Indexed: 01/06/2023]
Abstract
In the adult mammalian central nervous system (CNS), axonal damage often triggers neuronal cell death and glial activation, with very limited spontaneous axon regeneration. In this study, we performed optic nerve injury in adult naked mole-rats, the longest living rodent, with a maximum life span exceeding 30 years, and found that injury responses in this species are quite distinct from those in other mammalian species. In contrast to what is seen in other mammals, the majority of injured retinal ganglion cells (RGCs) survive with relatively high spontaneous axon regeneration. Furthermore, injured RGCs display activated signal transducer and activator of transcription-3 (STAT3), whereas astrocytes in the optic nerve robustly occupy and fill the lesion area days after injury. These neuron-intrinsic and -extrinsic injury responses are reminiscent of those in "cold-blooded" animals, such as fish and amphibians, suggesting that the naked mole-rat is a powerful model for exploring the mechanisms of neuronal injury responses and axon regeneration in mammals. J. Comp. Neurol. 525:380-388, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Kevin K Park
- Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, 33136
| | - Xueting Luo
- Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, 33136
| | - Skyler J Mooney
- Departments of Psychology and Cell and Systems Biology, University of Toronto, Toronto, Ontario, M5S 3G3, Canada
| | - Benjamin J Yungher
- Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, 33136
| | - Stephane Belin
- F.M. Kirby Neurobiology Center, Children's Hospital, and Department of Neurology, Harvard Medical School, Boston, Massachusetts, 02115
| | - Chen Wang
- F.M. Kirby Neurobiology Center, Children's Hospital, and Department of Neurology, Harvard Medical School, Boston, Massachusetts, 02115
| | - Melissa M Holmes
- Departments of Psychology and Cell and Systems Biology, University of Toronto, Toronto, Ontario, M5S 3G3, Canada
| | - Zhigang He
- F.M. Kirby Neurobiology Center, Children's Hospital, and Department of Neurology, Harvard Medical School, Boston, Massachusetts, 02115
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Chapter 5 - Restoring Vision to the Blind: Endogenous Regeneration. Transl Vis Sci Technol 2014; 3:7. [DOI: 10.1167/tvst.3.7.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 10/27/2014] [Indexed: 11/24/2022] Open
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Vega-Meléndez GS, Blagburn JM, Blanco RE. Ciliary neurotrophic factor and fibroblast growth factor increase the speed and number of regenerating axons after optic nerve injury in adult Rana pipiens. J Neurosci Res 2013; 92:13-23. [PMID: 24166589 DOI: 10.1002/jnr.23303] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 08/18/2013] [Accepted: 08/27/2013] [Indexed: 11/09/2022]
Abstract
Neurotrophins such as ciliary neurotrophic factor (CNTF) and brain-derived neurotrophic factor (BDNF) and growth factors such as fibroblast growth factor (FGF-2) play important roles in neuronal survival and in axonal outgrowth during development. However, whether they can modulate regeneration after optic nerve injury in the adult animal is less clear. The present study investigates the effects of application of these neurotrophic factors on the speed, number, and distribution of regenerating axons in the frog Rana pipiens after optic nerve crush. Optic nerves were crushed and the factors, or phosphate-buffered saline, were applied to the stump or intraocularly. The nerves were examined at different times after axotomy, using anterograde labeling with biotin dextran amine and antibody against growth-associated protein 43. We measured the length, number, and distribution of axons projecting beyond the lesion site. Untreated regenerating axons show an increase in elongation rate over 3 weeks. CNTF more than doubles this rate, FGF-2 increases it, and BDNF has little effect. In contrast, the numbers of regenerating axons that have reached 200 μm at 2 weeks were more than doubled by FGF-2, increased by CNTF, and barely affected by BDNF. The regenerating axons were preferentially distributed in the periphery of the nerve; although the numbers of axons were increased by neurotrophic factor application, this overall distribution was substantially unaffected.
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Affiliation(s)
- Giam S Vega-Meléndez
- Institute of Neurobiology, University of Puerto Rico Medical Sciences Campus, Old San Juan, Puerto Rico; Department of Anatomy and Neurobiology, University of Puerto Rico School of Medicine, San Juan, Puerto Rico
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Luo X, Salgueiro Y, Beckerman SR, Lemmon VP, Tsoulfas P, Park KK. Three-dimensional evaluation of retinal ganglion cell axon regeneration and pathfinding in whole mouse tissue after injury. Exp Neurol 2013; 247:653-62. [PMID: 23510761 DOI: 10.1016/j.expneurol.2013.03.001] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2013] [Revised: 02/25/2013] [Accepted: 03/01/2013] [Indexed: 11/24/2022]
Abstract
Injured retinal ganglion cell (RGC) axons do not regenerate spontaneously, causing loss of vision in glaucoma and after trauma. Recent studies have identified several strategies that induce long distance regeneration in the optic nerve. Thus, a pressing question now is whether regenerating RGC axons can find their appropriate targets. Traditional methods of assessing RGC axon regeneration use histological sectioning. However, tissue sections provide fragmentary information about axonal trajectory and termination. To unequivocally evaluate regenerating RGC axons, here we apply tissue clearance and light sheet fluorescence microscopy (LSFM) to image whole optic nerve and brain without physical sectioning. In mice with PTEN/SOCS3 deletion, a condition known to promote robust regeneration, axon growth followed tortuous paths through the optic nerve, with many axons reversing course and extending towards the eye. Such aberrant growth was prevalent in the proximal region of the optic nerve where strong astroglial activation is present. In the optic chiasms of PTEN/SOCS3 deletion mice and PTEN deletion/Zymosan/cAMP mice, many axons project to the opposite optic nerve or to the ipsilateral optic tract. Following bilateral optic nerve crush, similar divergent trajectory is seen at the optic chiasm compared to unilateral crush. Centrally, axonal projection is limited predominantly to the hypothalamus. Together, we demonstrate the applicability of LSFM for comprehensive assessment of optic nerve regeneration, providing in-depth analysis of the axonal trajectory and pathfinding. Our study indicates significant axon misguidance in the optic nerve and brain, and underscores the need for investigation of axon guidance mechanisms during optic nerve regeneration in adults.
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Affiliation(s)
- Xueting Luo
- Miami Project to Cure Paralysis, University of Miami, Miller School of Medicine, Miami, FL 33136, USA.
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Vidal Pizarro I, Swain GP, Selzer ME. Cell proliferation in the lamprey central nervous system. J Comp Neurol 2004; 469:298-310. [PMID: 14694540 DOI: 10.1002/cne.11013] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
After spinal cord transection, axons regenerate both in larval and adult lampreys. It is not known to what degree cells proliferate, even in the uninjured animal. Therefore, we have determined the prevalence of mitosis in the lamprey central nervous system (CNS). Bromodeoxyuridine (BrdU) was injected and incorporated for 4 hours into 2- to 5-year-old larvae, animals undergoing metamorphosis, and young adults. Labeled cells were counted in the rhombencephalon (where most supraspinal projecting neurons are located) and spinal cord. A mitotic index (MI) was calculated as the percentage of nuclei that were labeled. There was a seasonal variation in mitotic activity, with higher MIs occurring in summer. Within the summer, there was an additional transient spike in mitosis, especially in the rhombencephalon. There was no correlation between age and MI within the range of developmental stages examined. Baseline MIs in the rhombencephalon and spinal cord were approximately 0.15% and 0.20%, respectively. In most animals, the highest mitotic rates in both the rhombencephalon and spinal cord were seen in the ependyma, but many labeled cells were found in nonependymal regions as well. During the summer spike, almost all of the additional mitosis in the rhombencephalon was in the ependyma, but this finding was not true in the spinal cord. Many BrdU-labeled cells in the spinal cord and rhombencephalon were also stained by monoclonal antibodies specific for lamprey glial keratin but were never labeled by anti-neurofilament antibodies. These results suggest that (1) neurogenesis is uncommon in the lamprey CNS; (2) during most of the year, baseline gliogenesis occurs mainly in the ependyma with substantial contribution by nonependymal areas. During the summer, a spike of mitotic activity occurs in the ependyma of the rhombencephalon and throughout the spinal cord.
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Affiliation(s)
- Ivonne Vidal Pizarro
- University of Pennsylvania, Institute of Neurological Sciences, Philadelphia, Pennsylvania 19104, USA
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Dunlop SA, Tennant M, Beazley LD. Extent of retinal ganglion cell death in the frog Litoria moorei after optic nerve regeneration induced by lesions of different sizes. J Comp Neurol 2002; 446:276-87. [PMID: 11932943 DOI: 10.1002/cne.10213] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Some amphibian retinal ganglion cells die during optic nerve regeneration. Here we have investigated whether ganglion cell death in the frog Litoria moorei is associated with the lesion site. For one experimental series, the optic nerve lesion extended for 0.15 mm; in the other, it extended for 1.5 mm. The extent of ganglion cell death was estimated from cresyl violet-stained whole mounts at 24 weeks post lesion. In other animals, individual regenerating axons were visualised in the optic nerve by horseradish peroxidase (HRP) labelling from 1 day to 24 weeks post lesion; counterstaining with cresyl violet allowed examination of cells that repopulated the lesion site. Ganglion cell numbers fell significantly more after an extensive than after a localised lesion, long-term losses being 50% and 34%, respectively (P < 0.05). Regenerating axons were delayed in their passage across the cell-poor extensive lesion compared with the relatively cell-rich localised lesion. The differing rates of regeneration between series were matched by greater delay after extensive lesion in the return of visually guided behaviour as assessed by optokinetic horizontal head nystagmus. We suggest that delays in regeneration after an extensive lesion exacerbate ganglion cell death, indicating that conditions within the lesion are associated with the death of some ganglion cells.
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Affiliation(s)
- Sarah A Dunlop
- Department of Zoology, The University of Western Australia, Crawley, Western Australia 6009, Australia.
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Naito Y, Naito E, Honjo I, Newman A, Honrubia V. Effect of vestibular nerve section on cytochrome oxidase activity in the vestibular ganglion cells of the squirrel monkey. Hear Res 1995; 90:72-8. [PMID: 8975007 DOI: 10.1016/0378-5955(95)00148-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Cytochrome oxidase (CO) activity of the vestibular ganglion cells of the squirrel monkey was demonstrated histochemically under normal and experimental conditions. Under general anesthesia, right vestibular nerve section was performed on adult squirrel monkeys between the vestibular ganglion and brain stem. The left side was left intact and was used as a within-animal normal control. One squirrel monkey that did not undergo vestibular nerve section was also included in the normal group. Following a survival period of seven months, neurons in the vestibular ganglion of both sides were examined. In the normal control sides, a significant negative correlation between the size of the neuron and its optical density for CO stain was observed. Many neurons in the vestibular ganglion survived after vestibular nerve section, but their cell sizes and optical densities of CO stain decreased compared with those of the control side.
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Affiliation(s)
- Y Naito
- Department of Otolaryngology, Kyoto University, Japan
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Tennant M, Bruce SR, Beazley LD. Survival of ganglion cells which form the retino-retinal projection during optic nerve regeneration in the frog. Vis Neurosci 1993; 10:681-6. [PMID: 8338804 DOI: 10.1017/s095252380000537x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
During optic nerve regeneration in the frog, axons transiently grow along the opposite optic nerve forming a retino-retinal projection. In the present study, we crushed the left optic nerve in the frog Litoria (Hyla) moorei and later applied horseradish peroxidase (HRP) or diamidino yellow (DY) to the right optic nerve. In one series, retinae were examined 3 days after application of the tracer. The retino-retinal projection was found to be maximal at 5 weeks, fell significantly by 7 weeks, and returned to close-to-normal levels by 24 weeks. In a second series, we applied DY at 5 weeks as before but did not sacrifice the frogs until 7 weeks. Numbers of labeled ganglion cells were not significantly different from those frogs in the first series labeled and examined at 5 weeks. We conclude that ganglion cells giving rise to the retino-retinal projection had not died in appreciable numbers, presumably being sustained by collateral axons in the brain.
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Affiliation(s)
- M Tennant
- Department of Psychology, University of Western Australia, Nedlands
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Hung YH, Stelzner DJ. Frog tectal efferent axons fail to regenerate within the CNS but grow within peripheral nerve implants. Exp Neurol 1991; 112:273-83. [PMID: 2029927 DOI: 10.1016/0014-4886(91)90127-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Tectal efferent axons, located adjacent to the optic tract, fail to regenerate past diencephalic lesions in Rana pipiens even though optic axons regenerate after the same injury (M. J. Lyon and D. J. Stelzner, J. Comp. Neurol. 255: 511-525). We tested the possibility that tectal efferent axons can regenerate within peripheral nerve implants. A 6- to 8-mm segment of autologous sciatic nerve was implanted into the anterolateral (N = 23) or centrolateral (N = 22) portion of the dorsal surface of the tectum. Frogs survived for 6 (N = 16) or 12 weeks (N = 29) before the free end of the nerve was recut and HRP applied. A control group had the nerve crushed prior to the HRP application. Neurons within the tectum, near and medial to the implant site, were retrogradely labeled from the nerve graft in most experimental operates but no neurons were labeled in controls. In addition, neurons were also labeled in nuclei which projected to the tectum in a number of cases. Three times as many neurons were labeled in 12-week operates (42 +/- 46) as in 6-week operates (15 +/- 12). The morphology and location of labeled neurons in the tectum was similar to tectal efferent neurons except that the somal area of neurons labeled from the graft was significantly larger (41%) than normal tectal efferent neurons. The basic finding is similar to experiments using the same paradigm in the mammalian central nervous system (CNS). One difference is the minimal glial reaction at the graft insertion site.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- Y H Hung
- Department of Anatomy and Cell Biology, S.U.N.Y. Health Science Center, Syracuse 13210
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Beattie MS, Bresnahan JC, Lopate G. Metamorphosis alters the response to spinal cord transection in Xenopus laevis frogs. JOURNAL OF NEUROBIOLOGY 1990; 21:1108-22. [PMID: 2258724 DOI: 10.1002/neu.480210714] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A series of studies has examined the response of the spinal cord to lesions made at various stages prior to and after metamorphic climax in the clawed frog Xenopus laevis. Complete transections made between Nieuwkoop and Faber (1956) stages 50 and 62 were followed by gradual recovery of righting and coordinated swimming as animals metamorphosed into juveniles (stage 66). Examination of descending axonal projections using horseradish peroxidase (HRP) showed fibers crossing the lesion site and distributing to the caudal lumbar spinal cord. These fibers could be traced from more rostral spinal segments as well as from brainstem injections of HRP. No evidence for rostrally projecting fibers crossing the lesion was obtained. Juvenile frogs of varying ages failed to demonstrate recovery of coordinated swimming or reconstitution of spinal descending pathways. In an additional series of animals, spinal transections were made within 1 or 2 days of tail resorption to assess whether regenerative capacities extended at all into post-metamorphic stages. No evidence for regeneration was found. Studies of metamorphosing frogs after spinal transections showed that fibers crossed the lesion within 5-12 days of transection, well prior to the end of metamorphic climax; however, in some cases in which metamorphosis seemed arrested, little regeneration was observed. Immunocytochemical studies showed that fibers containing serotonin (5-HT) were included in the population of axons that rapidly crossed the lesion after transection at metamorphic stages. These results are compared to those for lesions of the dorsal columns and other systems in developing and juvenile Xenopus. It is suggested that both metamorphosis-related hormonal changes, and axon substrate pathways, may affect the regenerative response in the Xenopus central nervous system (CNS).
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Affiliation(s)
- M S Beattie
- Division of Neurosurgery, Ohio State University, Columbus 43210
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Marciano FF, Gocht A, Dentinger MP, Hof L, Csiza CK, Barron KD. Axonal regrowth in the amyelinated optic nerve of the myelin-deficient rat: ultrastructural observations and effects of ganglioside administration. J Comp Neurol 1990; 295:219-34. [PMID: 2358514 DOI: 10.1002/cne.902950206] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
It has been postulated that myelin degradation products may inhibit regrowth of mammalian central axons and that central nervous system (CNS) myelin and oligodendrocytes may constitute a "nonpermissive substrate" for axonal growth. To address these issues, we utilized an X-linked rat mutant, myelin-deficient or md. In the optic nerve of this mutant, 40 days and more postnatally, normal myelin is absent and oligodendrocytes are few (Dentinger et al. Brain Res. 344:255-266, 1985). Twenty-eight days before sacrifice, we operated on four groups of 50-day-old md rats and age-matched normal littermates according to the following protocols: 1) unilateral intraorbital optic nerve crush; 2) beginning within 1 hour of nerve crush, daily intraperitoneal injection of GM1 ganglioside (20 mg/kg) dissolved in phosphate-buffered saline (PBS); 3) daily intraperitoneal injection of PBS alone, also begun within 1 hour of nerve crush; 4) severance of the optic nerve immediately behind the papilla 16 or 21 days after the primary crush lesions. Additionally, normal and md rats were killed 4 and 14 days after unilateral optic nerve injury. Nerves of unoperated md rats and their normal littermates were also processed. In the operated animals that did not receive GM1, ultrastructural analysis 4, 14, and 28 days after lesioning revealed that md optic nerves contained significantly greater numbers of regenerating axons, including growth cones and varicosities, than nerves of normal rats. Notably, 28 days postoperatively, (group 1), regenerating axons were still abundant in md nerve, whereas, in nerves of normally myelinated littermates, axonal numbers were diminished markedly. Regenerating optic axons of both md and normally myelinated rats were oriented by linear astrocytic arrays and often were enclosed by astrocytic cytoplasm. In normal littermates, GM1 administration (group 2) induced a significant increase in the number of axons within the operative lesion. Paradoxically, GM1 inhibited the ordinarily robust regeneration of md axons. PBS-injected md and normal rats (group 3) showed no significant differences from noninjected, operated animals. Severance of the nerve at the papilla (group 4) 7-12 days before sacrifice confirmed the origination of axonal regrowth by retinal ganglion cells. The data provide in vivo support for a role of myelin breakdown products or the secretory products of oligodendroglia in the inhibition of regenerative axonal sprouting within mammalian CNS.
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Affiliation(s)
- F F Marciano
- Research Service (Neurology), Veterans Administration Medical Center, Albany, New York
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Stelzner DJ, Strauss JA. Increase in ganglion cell size after optic nerve regeneration in the frog, Rana pipiens. Exp Neurol 1988; 100:210-5. [PMID: 3258247 DOI: 10.1016/0014-4886(88)90213-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Even though optic regeneration is successful in the frog, Rana pipiens, at completion considerable ganglion cell loss has occurred. To determine whether ganglion cell loss affects the size of the remaining ganglion cells, these cells were back-filled with horseradish peroxidase. The size of one class of ganglion cell 6 months to 1 year following nerve crush injury (N = 4) was compared to that of normal cells of this class (N = 4). The average area of the perikaryon was 35% larger than normal (less than 0.01). This change is interpreted to reflect the increased metabolic needs of the neuron required to maintain a larger than normal axonal arbor.
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Affiliation(s)
- D J Stelzner
- Department of Anatomy and Cell Biology, SUNY Health Science Center, Syracuse 13210
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