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Onger ME, Altun G, Yildiran A. Pigment epithelium-derived factor enhances peripheral nerve regeneration through modulating oxidative stress and stem cells: An experimental study. Anat Rec (Hoboken) 2023; 306:2621-2635. [PMID: 36787348 DOI: 10.1002/ar.25177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 01/04/2023] [Accepted: 01/18/2023] [Indexed: 02/15/2023]
Abstract
Peripheral nerve injury is common and negatively affects an individual's quality of life. Drugs used for peripheral nerve regeneration should aim to eliminate symptoms such as neuropathic pain and have therapeutic effects. In recent studies, pigment epithelium-derived factor (PEDF) has been considered an essential therapeutic agent because of its potential neuroprotective properties. In this study, we aimed to investigate the efficacy of locally applied PEDF for peripheral nerve regeneration. Twenty-four Wistar albino male rats were used. The study groups included Injury (n = 12) and Injury+PEDF (n = 12). An injury model was created by applying 50 N pressure to the right sciatic nerves in groups, and 10 μg/kg local PEDF was injected into the Injury+PEDF group. After 28 days of recovery, functional tests and stereological, immunohistochemical, and biochemical analyses were performed. A significant difference was found between the Injury and Injury+PEDF groups in amplitude, whereas no difference was found in latency. The number of myelinated axons and the myelinated axon area increased significantly in the Injury+PEDF group, while no statistically significant difference was found in myelin sheath thickness. Superoxide dismutase, catalase, and glutathione peroxidase activities were increased by PEDF, whereas they were suppressed in mesenchymal stem cells. PEDF exerts functional, quantitative, and antioxidative effects on sciatic nerve injury during neuroregeneration. In addition, when oxidative stress parameters were examined, it was seen that PEDF reduced oxidative stress following sciatic nerve injury.
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Affiliation(s)
- Mehmet Emin Onger
- Department of Histology and Embryology, Faculty of Medicine, Ondokuz Mayıs University, Samsun, Turkey
- Department of Neuroscience, Health Science Institute, Ondokuz Mayıs University, Samsun, Turkey
| | - Gamze Altun
- Department of Histology and Embryology, Faculty of Medicine, Ondokuz Mayıs University, Samsun, Turkey
| | - Alisan Yildiran
- Department of Pediatrics, Faculty of Medicine, Ondokuz Mayıs University, Samsun, Turkey
- Department of Immunology, Faculty of Medicine, Ondokuz Mayıs University, Samsun, Turkey
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Graham MT, Sharma A, Padovano WM, Suresh V, Chiu A, Thon SM, Tuffaha S, Bell MAL. Optical absorption spectra and corresponding in vivo photoacoustic visualization of exposed peripheral nerves. JOURNAL OF BIOMEDICAL OPTICS 2023; 28:097001. [PMID: 37671115 PMCID: PMC10475953 DOI: 10.1117/1.jbo.28.9.097001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 08/15/2023] [Accepted: 08/21/2023] [Indexed: 09/07/2023]
Abstract
Significance Multispectral photoacoustic imaging has the potential to identify lipid-rich, myelinated nerve tissue in an interventional or surgical setting (e.g., to guide intraoperative decisions when exposing a nerve during reconstructive surgery by limiting operations to nerves needing repair, with no impact to healthy or regenerating nerves). Lipids have two optical absorption peaks within the NIR-II and NIR-III windows (i.e., 1000 to 1350 nm and 1550 to 1870 nm wavelength ranges, respectively) which can be exploited to obtain photoacoustic images. However, nerve visualization within the NIR-III window is more desirable due to higher lipid absorption peaks and a corresponding valley in the optical absorption of water. Aim We present the first known optical absorption characterizations, photoacoustic spectral demonstrations, and histological validations to support in vivo photoacoustic nerve imaging in the NIR-III window. Approach Four in vivo swine peripheral nerves were excised, and the optical absorption spectra of these fresh ex vivo nerves were characterized at wavelengths spanning 800 to 1880 nm, to provide the first known nerve optical absorbance spectra and to enable photoacoustic amplitude spectra characterization with the most optimal wavelength range. Prior to excision, the latter two of the four nerves were surrounded by aqueous, lipid-free, agarose blocks (i.e., 3% w/v agarose) to enhance acoustic coupling during in vivo multispectral photoacoustic imaging using the optimal NIR-III wavelengths (i.e., 1630 to 1850 nm) identified in the ex vivo studies. Results There was a verified characteristic lipid absorption peak at 1725 nm for each ex vivo nerve. Results additionally suggest that the 1630 to 1850 nm wavelength range can successfully visualize and differentiate lipid-rich nerves from surrounding water-containing and lipid-deficient tissues and materials. Conclusions Photoacoustic imaging using the optimal wavelengths identified and demonstrated for nerves holds promise for detection of myelination in exposed and isolated nerve tissue during a nerve repair surgery, with possible future implications for other surgeries and other optics-based technologies.
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Affiliation(s)
- Michelle T. Graham
- Johns Hopkins University, Department of Electrical and Computer Engineering, Baltimore, Maryland, United States
| | - Arunima Sharma
- Johns Hopkins University, Department of Electrical and Computer Engineering, Baltimore, Maryland, United States
| | - William M. Padovano
- Johns Hopkins School of Medicine, Department of Plastic and Reconstructive Surgery, Baltimore, Maryland, United States
| | - Visakha Suresh
- Johns Hopkins School of Medicine, Department of Plastic and Reconstructive Surgery, Baltimore, Maryland, United States
| | - Arlene Chiu
- Johns Hopkins University, Department of Electrical and Computer Engineering, Baltimore, Maryland, United States
| | - Susanna M. Thon
- Johns Hopkins University, Department of Electrical and Computer Engineering, Baltimore, Maryland, United States
| | - Sami Tuffaha
- Johns Hopkins School of Medicine, Department of Plastic and Reconstructive Surgery, Baltimore, Maryland, United States
| | - Muyinatu A. Lediju Bell
- Johns Hopkins University, Department of Electrical and Computer Engineering, Baltimore, Maryland, United States
- Johns Hopkins University, Department of Biomedical Engineering, Baltimore, Maryland, United States
- Johns Hopkins University, Department of Computer Science, Baltimore, Maryland, United States
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Wong AL, Hricz N, Malapati H, von Guionneau N, Wong M, Harris T, Boudreau M, Cohen-Adad J, Tuffaha S. A simple and robust method for automating analysis of naïve and regenerating peripheral nerves. PLoS One 2021; 16:e0248323. [PMID: 34234376 PMCID: PMC8263263 DOI: 10.1371/journal.pone.0248323] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 06/15/2021] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Manual axon histomorphometry (AH) is time- and resource-intensive, which has inspired many attempts at automation. However, there has been little investigation on implementation of automated programs for widespread use. Ideally such a program should be able to perform AH across imaging modalities and nerve states. AxonDeepSeg (ADS) is an open source deep learning program that has previously been validated in electron microscopy. We evaluated the robustness of ADS for peripheral nerve axonal histomorphometry in light micrographs prepared using two different methods. METHODS Axon histomorphometry using ADS and manual analysis (gold-standard) was performed on light micrographs of naïve or regenerating rat median nerve cross-sections prepared with either toluidine-resin or osmium-paraffin embedding protocols. The parameters of interest included axon count, axon diameter, myelin thickness, and g-ratio. RESULTS Manual and automatic ADS axon counts demonstrated good agreement in naïve nerves and moderate agreement on regenerating nerves. There were small but consistent differences in measured axon diameter, myelin thickness and g-ratio; however, absolute differences were small. Both methods appropriately identified differences between naïve and regenerating nerves. ADS was faster than manual axon analysis. CONCLUSIONS Without any algorithm retraining, ADS was able to appropriately identify critical differences between naïve and regenerating nerves and work with different sample preparation methods of peripheral nerve light micrographs. While there were differences between absolute values between manual and ADS, ADS performed consistently and required much less time. ADS is an accessible and robust tool for AH that can provide consistent analysis across protocols and nerve states.
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Affiliation(s)
- Alison L. Wong
- Department of Plastic and Reconstructive Surgery, Johns Hopkins University, Baltimore, MD, United States of America
| | - Nicholas Hricz
- Department of Plastic and Reconstructive Surgery, Johns Hopkins University, Baltimore, MD, United States of America
| | - Harsha Malapati
- Department of Plastic and Reconstructive Surgery, Johns Hopkins University, Baltimore, MD, United States of America
| | - Nicholas von Guionneau
- Department of Plastic and Reconstructive Surgery, Johns Hopkins University, Baltimore, MD, United States of America
| | - Michael Wong
- Department of Anesthesia, Dalhousie University Faculty of Medicine, Pain Management & Perioperative Medicine, Halifax, NS, Canada
| | - Thomas Harris
- Department of Plastic and Reconstructive Surgery, Johns Hopkins University, Baltimore, MD, United States of America
| | - Mathieu Boudreau
- NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada
| | - Julien Cohen-Adad
- NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada
| | - Sami Tuffaha
- Department of Plastic and Reconstructive Surgery, Johns Hopkins University, Baltimore, MD, United States of America
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Delibas B, Kuruoglu E, Bereket MC, Onger ME. Allantoin, a purine metabolite, enhances peripheral nerve regeneration following sciatic nerve injury in rats: A stereological and immunohistochemical study. J Chem Neuroanat 2021; 117:102002. [PMID: 34242746 DOI: 10.1016/j.jchemneu.2021.102002] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 06/08/2021] [Accepted: 07/03/2021] [Indexed: 11/19/2022]
Abstract
AIM Following peripheral nerve injury, in addition to axonal and myelin degeneration, a sharp increase is observed in cell numbers, especially Schwann cells, in the distal part of the injury. This study investigated the effect of allantoin, involved in purine catabolism, on the reactions occurring in the lesion area. MATERIAL AND METHOD An experimental sciatic nerve injury model was established with the application of pressure at 50 Newtons for 5 s to the right sciatic nerves of experimental animals following visualization with the help of pliers. Allantoin was administered to the test groups via the intraperitoneal (i.p.) route (10 mg/kg), at the same time every day for 30 days. The animals were sacrificed at the end of 30 days, following electromyography and Sciatic Function Index tests. Myelinated/unmyelinated axon numbers were evaluated stereologically. Myelin sheath thickness, axon diameter, mitotic activity, and functional improvement in muscles in this peripheral nerve degeneration model were investigated. The test results were then subjected to statistical analysis. RESULTS Allantoin was observed to exhibit curative effects in terms of function, although stereological tests revealed no morphological differences. CONCLUSION The i.p. administration of allantoin may have a beneficial effect on nerve healing.
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Affiliation(s)
- Burcu Delibas
- Department of Histology and Embryology, Faculty of Medicine, Ondokuz Mayıs University, Samsun, Turkey.
| | - Enis Kuruoglu
- Department of Neurosurgery, Faculty of Medicine, Ondokuz Mayıs University, Samsun, Turkey; Department of Neuroscience, Health Science Institute, Ondokuz Mayıs University, Samsun, Turkey
| | - Mehmet Cihan Bereket
- Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Ondokuz Mayıs University, Samsun, Turkey
| | - Mehmet Emin Onger
- Department of Histology and Embryology, Faculty of Medicine, Ondokuz Mayıs University, Samsun, Turkey; Department of Neuroscience, Health Science Institute, Ondokuz Mayıs University, Samsun, Turkey
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Odorico SK, Shulzhenko NO, Zeng W, Dingle AM, Francis DO, Poore SO. Effect of Nimodipine and Botulinum Toxin A on Peripheral Nerve Regeneration in Rats: A Pilot Study. J Surg Res 2021; 264:208-221. [PMID: 33838405 DOI: 10.1016/j.jss.2021.02.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 01/05/2021] [Accepted: 02/27/2021] [Indexed: 11/26/2022]
Abstract
BACKGROUND Peripheral nerve damage is a frequent problem, with an estimated 2.8%-5.0% of trauma admissions involving peripheral nerve injury. End-to-end, tension-free microsurgical repair (neurorrhaphy) is the current gold standard treatment for complete transection (neurotmesis). While neurorrhaphy reapproximates the nerve, it does not address the complex molecular regenerative process. Evidence suggests that botulinum toxin A (BTX) and nimodipine (NDP) may improve functional recovery, but mechanisms of action remain unknown. METHODS This research investigates BTX and NDP for their novel capacity to improve neural regeneration in the setting of neurorrhaphy using a Lewis rat tibial nerve neurotmesis model. In a triple-masked, placebo-controlled, randomized study design, we compared functional (rotarod, horizontal ladder walk), electrophysiological (conduction velocity, duration), and stereological (axon count, density) outcomes of rats treated with: NDP+saline injection, BTX+NDP, Saline+placebo, and BTX+placebo. Additional controls included sham surgery +/- BTX. RESULTS NDP+saline outperformed other treatment groups in the ladder walk. This group had the fewest deep slips (15.07% versus 30.77% in BTX+NDP, P = 0.122), and the most correct steps (70.53% versus 55.58% in BTX+NDP, P = 0.149) in functional testing. NDP+saline also had the fastest nerve conduction velocity (0.811m/s versus 0.598m/s in BTX+NDP, P = 0.126) among treatment groups. BTX+NDP had the highest axon count (10,012.36 versus 7,738.18 in NDP+Saline, P = 0.009). CONCLUSION This study is the first to test NDP with BTX in a multimodal assessment of nerve recovery following neurotmesis and neurorrhaphy. NDP outperformed BTX+NDP functionally. Future work will focus on nimodipine in an effort to improve nerve recovery in trauma patients.
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Affiliation(s)
- Scott K Odorico
- University of Wisconsin School of Medicine and Public Health, Division of Plastic Surgery, Department of Surgery, Madison, Wisconsin
| | - Nikita O Shulzhenko
- University of Wisconsin School of Medicine and Public Health, Division of Plastic Surgery, Department of Surgery, Madison, Wisconsin
| | - Weifeng Zeng
- University of Wisconsin School of Medicine and Public Health, Division of Plastic Surgery, Department of Surgery, Madison, Wisconsin
| | - Aaron M Dingle
- University of Wisconsin School of Medicine and Public Health, Division of Plastic Surgery, Department of Surgery, Madison, Wisconsin
| | - David O Francis
- University of Wisconsin School of Medicine and Public Health, Division of Otolaryngology, Department of Surgery, Madison, Wisconsin; University of Wisconsin School of Medicine and Public Health, Wisconsin Surgical Outcomes Research Program, Department of Surgery, Madison, Wisconsin
| | - Samuel O Poore
- University of Wisconsin School of Medicine and Public Health, Division of Plastic Surgery, Department of Surgery, Madison, Wisconsin.
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Costa AL, Papadopulos N, Porzionato A, Natsis K, Bassetto F, Tiengo C, Giunta R, Soldado F, Bertelli JA, Baeza AR, Battiston B, Titolo P, Tos P, Radtke C, Aszmann O, Moschella F, Cordova A, Toia F, Perrotta RE, Ronchi G, Geuna S, Colonna MR. Studying nerve transfers: Searching for a consensus in nerve axons count. J Plast Reconstr Aesthet Surg 2021; 74:2731-2736. [PMID: 33962889 DOI: 10.1016/j.bjps.2021.03.064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 03/13/2021] [Indexed: 11/26/2022]
Abstract
Axonal count is the base for efficient nerve transfer; despite its capital importance, few studies have been published on human material, most research approaches being performed on experimental animal models of nerve injury. Thus, standard analysis methods are still lacking. Quantitative data obtained have to be reproducible and comparable with published data by other research groups. To share results with the scientific community, the standardization of quantitative analysis is a fundamental step. For this purpose, the experiences of the Italian, Austrian, German, Greek, and Iberian-Latin American groups have been compared with each other and with the existing literature to reach a consensus in the fiber count and draw up a protocol that can make future studies from different centers comparable. The search for a standardization of the methodology was aimed to reduce all the factors that are associated with an increase in the variability of the results. All the preferential methods to be used have been suggested. On the other hand, alternative methods and different methods have been identified to achieve the same goal, which in our experience are completely comparable; therefore, they can be used indifferently by the different centers according to their experience and availability.
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Affiliation(s)
- Alfio Luca Costa
- Department of Human Pathology of the Adult, the Child and the Adolescent, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy.
| | - Nikolaos Papadopulos
- Department of Plastic Surgery and Burns, Alexandroupoli University Hospital, Democritus University of Thace, Alexandroupoli, Greece
| | - Andrea Porzionato
- Department of Neurosciences, Institute of Human Anatomy, University of Padova, Padova, Italy
| | - Konstantinos Natsis
- Department of Anatomy and Surgical Anatomy, (Chairperson: Professor Dr. K. NATSIS), Medical School, Aristotle University of Thessaloniki, Greece
| | - Franco Bassetto
- Clinic of Plastic Surgery, Padova University Hospital, Padova, Italy
| | - Cesare Tiengo
- Clinic of Plastic Surgery, Padova University Hospital, Padova, Italy
| | - Riccardo Giunta
- Division of Hand, Plastic and Aesthetic Surgery, Ludwig-Maximilians-University (LMU), Pettenkoferstraße. 8a, 80336 Munich, Germany
| | - Francisco Soldado
- Pediatric Upper Extremity Surgery and Microsurgery, Vithas San Jose Hospital, Vitoria and Hospital HM nens, Barcelona, Spain
| | - Jayme Augusto Bertelli
- Department of Orthopedic Surgery, Governador Celso Ramos Hospital, Florianópolis, Brazil
| | - Alfonso Rodrìguez Baeza
- Unit of Human Anatomy and Embryology, Department of Morphological Sciences, Faculty of Medicine, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Bellaterra, 08193 Barcelona, Spain
| | - Bruno Battiston
- Human Anatomy Unit, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Paolo Titolo
- Human Anatomy Unit, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Pierluigi Tos
- Azienda Ospedaliero-Universitaria Citta della Salute e della Scienza di Torino, Depatment of Traumatology, Turin, Italy
| | - Christine Radtke
- Hand Surgery and Reconstructive Microsurgery Unit, ASST G Pini-CTO, Milano, Italy
| | - Oscar Aszmann
- Hand Surgery and Reconstructive Microsurgery Unit, ASST G Pini-CTO, Milano, Italy
| | - Francesco Moschella
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Medical University of Vienna, Vienna, Austria
| | - Adriana Cordova
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Medical University of Vienna, Vienna, Austria
| | - Francesca Toia
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Medical University of Vienna, Vienna, Austria
| | - Rosario Emanuele Perrotta
- Section of Plastic and Reconstructive Surgery. Department of Surgical, Oncological and Oral Sciences. University of Palermo, Italy
| | - Guilia Ronchi
- Department of Plastic and Reconstructive Surgery, University of Catania, Catania 95100, Italy; Department of Clinical and Biological Sciences, University of Torino, Turin, Italy
| | - Stefano Geuna
- Department of Plastic and Reconstructive Surgery, University of Catania, Catania 95100, Italy
| | - Michele Rosario Colonna
- Department of Human Pathology of the Adult, the Child and the Adolescent, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy
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Dzurjašková Z, Blaško J, Tomori Z, Vanický I. A method to prepare large resin sections for counting myelinated axons in rodent CNS and PNS structures. Neurosci Lett 2021; 750:135767. [PMID: 33636286 DOI: 10.1016/j.neulet.2021.135767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 02/08/2021] [Accepted: 02/21/2021] [Indexed: 10/22/2022]
Abstract
We present a method that allows preparing histological sections from large blocks of nervous tissue embedded in epoxy resin. Resin-embedding provides excellent resolution especially for the myelin-rich white matter and is often being used for visualizing the myelinated axons in peripheral nerves. However, because of the limited penetration of the reagents, only very small tissue specimens can be processed in this way. Here, we describe a method that enables to embed large specimens and their sectioning on a standard sliding microtome. To process the large specimens, modifications in several steps of the processing technique had to be made. In this paper we demonstrate, that with this technique 1-3 μm thick transversal sections can be prepared from the resin-embedded specimens as large as rat brain hemisphere. Such a large section allows simultaneously: 1.) overviewing and delineating the gross anatomical structures, and 2.) observing the subcellular details at the highest possible optical magnifications. Such a large section with excellent resolution allows application of unbiased stereological methods and reliable quantification of very small objects within the area of interest.
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Affiliation(s)
- Zuzana Dzurjašková
- Institute of Neurobiology, Biomedical Research Center of the Slovak Academy of Sciences, Šoltésovej 4, 040 01 Košice, Slovakia.
| | - Juraj Blaško
- Institute of Neurobiology, Biomedical Research Center of the Slovak Academy of Sciences, Šoltésovej 4, 040 01 Košice, Slovakia.
| | - Zoltán Tomori
- Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 040 01 Košice, Slovakia.
| | - Ivo Vanický
- Institute of Neurobiology, Biomedical Research Center of the Slovak Academy of Sciences, Šoltésovej 4, 040 01 Košice, Slovakia.
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8
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Jassim AH, Cavanaugh M, Shah JS, Willits R, Inman DM. Transcorneal Electrical Stimulation Reduces Neurodegenerative Process in a Mouse Model of Glaucoma. Ann Biomed Eng 2021; 49:858-870. [PMID: 32974756 PMCID: PMC7854493 DOI: 10.1007/s10439-020-02608-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 09/02/2020] [Indexed: 12/19/2022]
Abstract
Glaucoma is a neurodegenerative disease in which the retinal ganglion cell axons of the optic nerve degenerate concomitant with synaptic changes in the retina, leading finally to death of the retinal ganglion cells (RGCs). Electrical stimulation has been used to improve neural regeneration in a variety of systems, including in diseases of the retina. Therefore, the focus of this study was to investigate whether transcorneal electrical stimulation (TES) in the DBA2/J mouse model of glaucoma could improve retinal or optic nerve pathology and serve as a minimally invasive treatment option. Mice (10 months-old) received 21 sessions of TES over 8 weeks, after which we evaluated RGC number, axon number, and anterograde axonal transport using histology and immunohistochemistry. To gain insight into the mechanism of proposed protection, we also evaluated inflammation by quantifying CD3+ T-cells and Iba1+ microglia; perturbations in metabolism were shown via the ratio pAMPK to AMPK, and changes in trophic support were tested using protein capillary electrophoresis. We found that TES resulted in RGC axon protection, a reduction in inflammatory cells and their activation, improved energy homeostasis, and a reduction of the cell death-associated p75NTR. Collectively, the data indicated that TES maintained axons, decreased inflammation, and increased trophic factor support, in the form of receptor presence and energy homeostasis, suggesting that electrical stimulation impacts several facets of the neurodegenerative process in glaucoma.
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Affiliation(s)
- Assraa Hassan Jassim
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH, USA
- Department of Basic and Translational Sciences, University of Pennsylvania, Philadelphia, PA, USA
| | - McKay Cavanaugh
- Department of Biomedical Engineering, University of Akron, Akron, OH, USA
| | | | - Rebecca Willits
- Department of Biomedical Engineering, University of Akron, Akron, OH, USA.
- Department of Chemical Engineering, Northeastern University, Boston, MA, USA.
| | - Denise M Inman
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH, USA.
- North Texas Eye Research Institute, UNT-HSC, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA.
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9
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Recovery and Regrowth After Nerve Repair: A Systematic Analysis of Four Repair Techniques. J Surg Res 2020; 251:311-320. [DOI: 10.1016/j.jss.2020.01.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 12/30/2019] [Accepted: 01/26/2020] [Indexed: 02/05/2023]
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10
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Design-Based stereology and binary image histomorphometry in nerve assessment. J Neurosci Methods 2020; 336:108635. [PMID: 32070676 PMCID: PMC8045463 DOI: 10.1016/j.jneumeth.2020.108635] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 02/02/2020] [Accepted: 02/14/2020] [Indexed: 01/13/2023]
Abstract
BACKGROUND Stereology and histomorphometry are widely used by investigators to quantify nerve characteristics in normal and pathological states, including nerve injury and regeneration. While these methods of analysis are complementary, no study to date has systematically compared both approaches in peripheral nerve. This study investigated the reliability of design-based stereology versus semi-automated binary imaging histomorphometry for assessing healthy peripheral nerve characteristics. NEW METHOD Stereological analysis was compared to histomorphometry with binary image analysis on uninjured sciatic nerves to determine nerve fiber number, nerve area, neural density, and fiber distribution. RESULTS Sciatic nerves were harvested from 6 male Lewis rats, aged 8-12 weeks for comprehensive analysis of 6 nerve specimens. From each animal, sciatic nerve specimens were fixed, stained, and sectioned for analysis by light and electron microscopy. Both histomorphometry and stereological peripheral nerve analyses were performed on all specimens by two blinded and independent investigators who quantified nerve fiber count, fiber width, density, and related distribution parameters. COMPARISON WITH EXISTING METHODS Histomorphometry and stereological analysis provided similar outcomes in nerve fiber number and total nerve area. However, the light microscopy, but not electron microscopy, stereological analysis yielded higher nerve fiber area compared to histomorphometry or manual measurement. CONCLUSION Both methods measure similar fiber number and overall nerve fiber area; however, stereology with light microscopy quantified higher fiber area. Histomorphometry optimizes throughput and comprehensive analysis but requires user thresholding.
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Howarth HM, Kadoor A, Salem R, Nicolds B, Adachi S, Kanaris A, Lovering RM, Brown JM, Shah SB. Nerve lengthening and subsequent end-to-end repair yield more favourable outcomes compared with autograft repair of rat sciatic nerve defects. J Tissue Eng Regen Med 2019; 13:2266-2278. [PMID: 31670904 DOI: 10.1002/term.2980] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 09/17/2019] [Accepted: 10/04/2019] [Indexed: 12/31/2022]
Abstract
Outcomes of end-to-end nerve repairs are more successful compared with outcomes of repairs bridged by nerve grafts. However, end-to-end repairs are not always possible for large nerve gaps, as excessive tension may cause catastrophic failure. In this study, we built on previous nerve-lengthening studies to test the hypotheses that gradual lengthening of the proximal stump across a large nerve gap enables an end-to-end repair and such a repair results in more favourable regenerative outcomes than autografts, which represent the gold standard in bridging nerve gaps. To test these, we compared structural and functional outcomes in Lewis rats after repair of sciatic nerve gaps using either autografts or a novel compact internal fixator device, which was used to lengthen proximal nerve stumps towards the distal stump over 2 weeks, prior to end-to-end repair. Twelve weeks after the initial injury, outcomes following nerve lengthening/end-to-end repair were either comparable or superior in every measure compared with repair by autografting. The sciatic functional index was not significantly different between groups at 12 weeks. However, we observed a reduced rate of contracture and corresponding significant increase in paw length in the lengthening group. This functional improvement was consistent with structural regeneration; axonal growth distal to the injury was denser and more evenly distributed compared with the autograft group, suggesting substantial regeneration into both tibial and peroneal branches of the sciatic nerve. Our findings show that end-to-end repairs following nerve lengthening are possible for large gaps and that this strategy may be superior to graft-based repairs.
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Affiliation(s)
- Holly M Howarth
- Department of Bioengineering, University of California, San Diego, La Jolla, CA
| | - Adarsh Kadoor
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA
| | - Rayeheh Salem
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA
| | - Brogan Nicolds
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA
| | - Stephanie Adachi
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA
| | - Achilles Kanaris
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA
| | - Richard M Lovering
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, MD
| | - Justin M Brown
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA
| | - Sameer B Shah
- Department of Bioengineering, University of California, San Diego, La Jolla, CA.,Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA.,Research Service, VA San Diego Healthcare System, San Diego, CA
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12
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The reliability of the isotropic fractionator method for counting total cells and neurons. J Neurosci Methods 2019; 326:108392. [PMID: 31394117 DOI: 10.1016/j.jneumeth.2019.108392] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Revised: 07/21/2019] [Accepted: 08/03/2019] [Indexed: 11/21/2022]
Abstract
BACKGROUND The Isotropic Fractionator (IF) is a method to determine the cellular composition of nervous tissue. It has been mostly applied to assess variation across species, where differences are expected to be large enough not to be masked by methodological error. However, understanding the sources of variation in the method is important if the goal is to detect smaller differences, for example, in same-species comparisons. Comparisons between different mice strains suggest that the IF is consistent enough to detect these differences. Nevertheless, the reliability of the method has not yet been examined directly. METHOD In this study, we evaluate the reliability of the method for the determination of cellular and neuronal numbers of Swiss mice. We performed repeated cell counts of the same material by different experimenters to quantify different sources of variation. RESULTS In total cell counts, we observed that for the cerebral cortex most of the variance was at the counter level. For the cerebellum, most of the variance is attributed to the sample itself. As for neurons, random error along with the immunostaining correspond to most of the variation, both in the cerebral cortex and in the cerebellum. Test-retest reliability coefficients were relatively high, especially for cell counts. CONCLUSIONS Although biases between counters and random variation in staining could be problematic when aggregating data from different sources, we offer practical suggestions to improve the reliability of the method. While small, this study is a most needed step towards more precise measurement of the brain's cellular composition.
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13
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Koschade SE, Koch MA, Braunger BM, Tamm ER. Efficient determination of axon number in the optic nerve: A stereological approach. Exp Eye Res 2019; 186:107710. [PMID: 31254512 DOI: 10.1016/j.exer.2019.107710] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Revised: 05/26/2019] [Accepted: 06/21/2019] [Indexed: 11/26/2022]
Abstract
Quantifying the number of axons in the optic nerve is of interest in many research questions. Here, we show that a stereological method allows simple, efficient, precise and unbiased determination of the total axon number in the murine optic nerve. Axons in semi-thin optic nerve cross sections from untreated eyes (n = 21) and eyes subjected to retinal damage by intravitreous NMDA injections (n = 32) or PBS controls (n = 5) were manually identified, counted and digitally labeled by hand. A stereological procedure was empirically tested with systematic combinations of different sampling methods (simple random sampling without replacement, systematic uniform random sampling, stratified random sampling) and sampling parameters. Extensive numerical Monte Carlo experiments were performed to evaluate their large-sample properties. Our results demonstrate reliable determination of total axon number and superior performance compared to other methods at a small fraction of the time required for a full manual count. We specify suitable sampling parameters for the adoption of an efficient stereological sampling scheme, give empirical estimates of the additionally introduced sampling variance to facilitate experimental planning, and offer AxonCounter, an easy-to-use plugin implementing these stereological methods for the multi-platform image processing application NIH ImageJ.
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Affiliation(s)
- Sebastian E Koschade
- Institute of Human Anatomy and Embryology, University of Regensburg, Regensburg, Germany.
| | - Marcus A Koch
- Institute of Human Anatomy and Embryology, University of Regensburg, Regensburg, Germany
| | - Barbara M Braunger
- Institute of Human Anatomy and Embryology, University of Regensburg, Regensburg, Germany; Institute of Anatomy and Cell Biology, Julius-Maximilians-University of Würzburg, Würzburg, Germany
| | - Ernst R Tamm
- Institute of Human Anatomy and Embryology, University of Regensburg, Regensburg, Germany.
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14
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Abstract
Qualitative histopathology has been the gold standard for evaluation of morphological tissue changes in all organ systems, including the peripheral nervous system. However, the human eye is not sensitive enough to detect small changes in quantity or size. Peripheral nervous system toxicity can manifest as subtle changes in neuron size, neuron number, axon size, number of myelinated or unmyelinated axons, or number of nerve fibers. Detection of these changes may be beyond the sensitivity of the human eye alone, necessitating quantitative approaches in some cases. Although 2-dimensional (2D) histomorphometry can provide additional information and is more sensitive than qualitative evaluation alone, the results are not always representative of the entire tissue and assumptions about the tissue can lead to bias, or inaccuracies, in the data. Design-based stereology provides 3D estimates of number, volume, surface area, or length, and stereological principles can be applied to peripheral nervous system tissues to obtain accurate and precise estimates, such as neuron number and size, axon number, and total intraepidermal nerve fiber length. This review describes practical stereological approaches to 3 compartments of the peripheral nervous system: ganglia, peripheral nerves, and intraepidermal nerve fibers.
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15
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Hendry JM, Alvarez-Veronesi MC, Chiang C, Gordon T, Borschel GH. Neurofilament-histomorphometry comparison in the evaluation of unmyelinated axon regeneration following peripheral nerve injury: An alternative to electron microscopy. J Neurosci Methods 2019; 320:37-43. [DOI: 10.1016/j.jneumeth.2019.03.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 03/02/2019] [Accepted: 03/05/2019] [Indexed: 11/16/2022]
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16
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Acer N, Turgut M. Evaluation of Brachial Plexus Using Combined Stereological Techniques of Diffusion Tensor Imaging and Fiber Tracking. J Brachial Plex Peripher Nerve Inj 2019; 14:e16-e23. [PMID: 31198435 PMCID: PMC6561765 DOI: 10.1055/s-0039-1687913] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 02/18/2019] [Indexed: 02/03/2023] Open
Abstract
Background Brachial plexus (BP) is composed of intercommunications among the ventral roots of the nerves C5, C6, C7, C8, and T1 in the neck. The in vivo and in vitro evaluation of axons of the peripheral nervous system is performed using different techniques. Recently, many studies describing the application of fiber tractography and stereological axon number estimation to peripheral nerves have been published. Methods Various quantitative parameters of nerve fibers, including axon number, density, axonal area, and myelin thickness, can be estimated using stereological techniques. In vivo three-dimensional reconstruction of axons of BP can be visualized using a combined technique of diffusion tensor imaging (DTI) and fiber tracking with the potential to evaluate nerve fiber content. Conclusion It is concluded that terminal branches of BP can be successfully visualized using DTI, which is a highly reproducible method for the evaluation of BP as it shows anatomical and functional features of neural structures. We believe that quantitative morphological findings obtained from BP will be useful for new experimental, developmental, and pathological studies in the future.
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Affiliation(s)
- Niyazi Acer
- Department of Anatomy, Erciyes University School of Medicine, Kayseri, Turkey
| | - Mehmet Turgut
- Department of Neurosurgery, Adnan Menderes University School of Medicine, Aydın, Turkey
- Department of Histology and Embryology, Adnan Menderes University Health Sciences Institute, Aydın, Turkey
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17
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Deniz ÖG, Altun G, Kaplan AA, Yurt KK, von Bartheld CS, Kaplan S. A concise review of optical, physical and isotropic fractionator techniques in neuroscience studies, including recent developments. J Neurosci Methods 2018; 310:45-53. [PMID: 30048673 PMCID: PMC6251756 DOI: 10.1016/j.jneumeth.2018.07.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 06/18/2018] [Accepted: 07/17/2018] [Indexed: 11/30/2022]
Abstract
Stereology is a collection of methods which makes it possible to produce interpretations about actual three-dimensional features of objects based on data obtained from their two-dimensional sections or images. Quantitative morphological studies of the central nervous system have undergone significant development. In particular, new approaches known as design-based methods have been successfully applied to neuromorphological research. The morphology of macroscopic and microscopic structures, numbers of cells in organs and structures, and geometrical features such as length, volume, surface area and volume components of the organ concerned can be estimated in an unbiased manner using stereological techniques. The most practical and simplest stereological method is the fractionator technique, one of the most widely used methods for total particle number estimation. This review summarizes fractionator methods in theory and in practice. The most important feature of the methods is the simplicity of its application and underlying reasoning. Although there are three different types of the fractionator method, physical, optical and isotropic (biochemical), the logic underlying its applications remains the same. The fractionator method is one of the strongest and best options among available methods for estimation of the total number of cells in a given structure or organ. The second part of this review focuses on recent developments in stereology, including how to deal with lost caps, with tissue section deformation and shrinkage, and discusses issues of calibration, particle identification, and the role of stereology in the era of a non-histological alternative to counting of cells, the isotropic fractionator (brain soup technique).
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Affiliation(s)
- Ömür Gülsüm Deniz
- Department of Histology and Embryology, Medical Faculty, Ondokuz Mayıs University, Samsun, Turkey
| | - Gamze Altun
- Department of Histology and Embryology, Medical Faculty, Ondokuz Mayıs University, Samsun, Turkey
| | - Arife Ahsen Kaplan
- Department of Histology and Embryology, Medical Faculty, Ondokuz Mayıs University, Samsun, Turkey
| | - Kiymet Kübra Yurt
- Department of Histology and Embryology, Medical Faculty, Ondokuz Mayıs University, Samsun, Turkey
| | - Christopher S von Bartheld
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV 89557, USA
| | - Suleyman Kaplan
- Department of Histology and Embryology, Medical Faculty, Ondokuz Mayıs University, Samsun, Turkey.
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Long-Term In Vivo Evaluation of Chitosan Nerve Guide Properties with respect to Two Different Sterilization Methods. BIOMED RESEARCH INTERNATIONAL 2018; 2018:6982738. [PMID: 29967779 PMCID: PMC6008694 DOI: 10.1155/2018/6982738] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 04/22/2018] [Indexed: 11/18/2022]
Abstract
Severe peripheral nerve injuries are reconstructed either with autologous nerve grafts (gold standard) or alternatively with clinically approved artificial nerve guides. The most common method used to sterilize these medical products is ethylene oxide gassing (EO). However, this method has several disadvantages. An alternative, which has been barely studied so far, represents beta irradiation (β). In previous studies, we developed an artificial nerve guide made of chitosan (chitosan nerve guide, CNG), a biomaterial that is known to potentially retain toxic residues upon EO sterilization. Therefore, we analyzed the long-term regeneration-supporting and mechanical properties of CNGs upon their sterilization with EO or β and their following application in unilateral repair of 12 mm gaps of the rat sciatic nerve. Over a period of 76 weeks, we serially evaluated the recovery of motor functions, the possible emergence of an inflammation in the surrounding connective tissue, the regrowth of axons into the distal nerve, and possible changes in the material properties. Our first long-term evaluation did not reveal significant differences between both sterilization methods. Thus, β is as appropriate as commonly used EO for sterilization of CNGs; however, it may slightly increase the stiffness of the biomaterial over time.
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19
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von Bartheld CS. Myths and truths about the cellular composition of the human brain: A review of influential concepts. J Chem Neuroanat 2017; 93:2-15. [PMID: 28873338 DOI: 10.1016/j.jchemneu.2017.08.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 08/16/2017] [Accepted: 08/17/2017] [Indexed: 11/17/2022]
Abstract
Over the last 50 years, quantitative methodology has made important contributions to our understanding of the cellular composition of the human brain. Not all of the concepts that emerged from quantitative studies have turned out to be true. Here, I examine the history and current status of some of the most influential notions. This includes claims of how many cells compose the human brain, and how different cell types contribute and in what ratios. Additional concepts entail whether we lose significant numbers of neurons with normal aging, whether chronic alcohol abuse contributes to cortical neuron loss, whether there are significant differences in the quantitative composition of cerebral cortex between male and female brains, whether superior intelligence in humans correlates with larger numbers of brain cells, and whether there are secular (generational) changes in neuron number. Do changes in cell number or changes in ratios of cell types accompany certain diseases, and should all counting methods, even the theoretically unbiased ones, be validated and calibrated? I here examine the origin and the current status of major influential concepts, and I review the evidence and arguments that have led to either confirmation or refutation of such concepts. I discuss the circumstances, assumptions and mindsets that perpetuated erroneous views, and the types of technological advances that have, in some cases, challenged longstanding ideas. I will acknowledge the roles of key proponents of influential concepts in the sometimes convoluted path towards recognition of the true cellular composition of the human brain.
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Affiliation(s)
- Christopher S von Bartheld
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Mailstop 352, Reno, NV 89557, USA.
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20
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von Bartheld CS, Bahney J, Herculano-Houzel S. The search for true numbers of neurons and glial cells in the human brain: A review of 150 years of cell counting. J Comp Neurol 2016; 524:3865-3895. [PMID: 27187682 PMCID: PMC5063692 DOI: 10.1002/cne.24040] [Citation(s) in RCA: 552] [Impact Index Per Article: 69.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 05/13/2016] [Accepted: 05/16/2016] [Indexed: 12/13/2022]
Abstract
For half a century, the human brain was believed to contain about 100 billion neurons and one trillion glial cells, with a glia:neuron ratio of 10:1. A new counting method, the isotropic fractionator, has challenged the notion that glia outnumber neurons and revived a question that was widely thought to have been resolved. The recently validated isotropic fractionator demonstrates a glia:neuron ratio of less than 1:1 and a total number of less than 100 billion glial cells in the human brain. A survey of original evidence shows that histological data always supported a 1:1 ratio of glia to neurons in the entire human brain, and a range of 40-130 billion glial cells. We review how the claim of one trillion glial cells originated, was perpetuated, and eventually refuted. We compile how numbers of neurons and glial cells in the adult human brain were reported and we examine the reasons for an erroneous consensus about the relative abundance of glial cells in human brains that persisted for half a century. Our review includes a brief history of cell counting in human brains, types of counting methods that were and are employed, ranges of previous estimates, and the current status of knowledge about the number of cells. We also discuss implications and consequences of the new insights into true numbers of glial cells in the human brain, and the promise and potential impact of the newly validated isotropic fractionator for reliable quantification of glia and neurons in neurological and psychiatric diseases. J. Comp. Neurol. 524:3865-3895, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
| | - Jami Bahney
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, USA
| | - Suzana Herculano-Houzel
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, and Instituto Nacional de Neurociência Translacional, CNPq/MCT, Brasil
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21
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von Bartheld CS, Bahney J, Herculano-Houzel S. The search for true numbers of neurons and glial cells in the human brain: A review of 150 years of cell counting. J Comp Neurol 2016; 524:3865-3895. [PMID: 27187682 DOI: 10.1002/cne.2404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 05/13/2016] [Accepted: 05/16/2016] [Indexed: 05/25/2023]
Abstract
For half a century, the human brain was believed to contain about 100 billion neurons and one trillion glial cells, with a glia:neuron ratio of 10:1. A new counting method, the isotropic fractionator, has challenged the notion that glia outnumber neurons and revived a question that was widely thought to have been resolved. The recently validated isotropic fractionator demonstrates a glia:neuron ratio of less than 1:1 and a total number of less than 100 billion glial cells in the human brain. A survey of original evidence shows that histological data always supported a 1:1 ratio of glia to neurons in the entire human brain, and a range of 40-130 billion glial cells. We review how the claim of one trillion glial cells originated, was perpetuated, and eventually refuted. We compile how numbers of neurons and glial cells in the adult human brain were reported and we examine the reasons for an erroneous consensus about the relative abundance of glial cells in human brains that persisted for half a century. Our review includes a brief history of cell counting in human brains, types of counting methods that were and are employed, ranges of previous estimates, and the current status of knowledge about the number of cells. We also discuss implications and consequences of the new insights into true numbers of glial cells in the human brain, and the promise and potential impact of the newly validated isotropic fractionator for reliable quantification of glia and neurons in neurological and psychiatric diseases. J. Comp. Neurol. 524:3865-3895, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
| | - Jami Bahney
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, USA
| | - Suzana Herculano-Houzel
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, and Instituto Nacional de Neurociência Translacional, CNPq/MCT, Brasil
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22
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Önger ME, Delibaş B, Türkmen AP, Erener E, Altunkaynak BZ, Kaplan S. The role of growth factors in nerve regeneration. Drug Discov Ther 2016; 10:285-291. [PMID: 27746416 DOI: 10.5582/ddt.2016.01058] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Nerve injuries result in functional loss in the innervated organ or body parts, and recovery is difficult unless surgical treatment has been done. Different surgical treatments have been suggested for nerve repair. Tissue engineering related to growth factors has arisen as an alternative approach for triggering and improving nerve regeneration. Therefore, the aim of this review is to provide a comprehensive analysis related to growth factors as tools for optimizing the regeneration process. Studies and reviews on the use of growth factors for nerve regeneration were compiled over the course of the review. According to literature review, it may be concluded that growth factors from different sources present promising treatment related to nerve regeneration involved in neuronal differentiation, greater myelination and axonal growth and proliferation of specific cells for nerve repair.
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Affiliation(s)
- Mehmet Emin Önger
- Department of Histology and Embryology, Faculty of Medicine, Ondokuz Mayis University
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23
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Fregnan F, Ciglieri E, Tos P, Crosio A, Ciardelli G, Ruini F, Tonda-Turo C, Geuna S, Raimondo S. Chitosan crosslinked flat scaffolds for peripheral nerve regeneration. ACTA ACUST UNITED AC 2016; 11:045010. [PMID: 27508969 DOI: 10.1088/1748-6041/11/4/045010] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Chitosan (CS) has been widely used in a variety of biomedical applications, including peripheral nerve repair, due to its excellent biocompatibility, biodegradability, readily availability and antibacterial activity. In this study, CS flat membranes, crosslinked with dibasic sodium phosphate (DSP) alone (CS/DSP) or in association with the γ-glycidoxypropyltrimethoxysilane (CS/GPTMS_DSP), were fabricated with a solvent casting technique. The constituent ratio of crosslinking agents and CS were previously selected to obtain a composite material having both adequate mechanical properties and high biocompatibility. In vitro cytotoxicity tests showed that both CS membranes allowed cell survival and proliferation. Moreover, CS/GPTMS_DSP membranes promoted cell adhesion, induced Schwann cell-like morphology and supported neurite outgrowth from dorsal root ganglia explants. Preliminary in vivo tests carried out on both types of nerve scaffolds (CS/DSP and CS/GPTMS_DSP membranes) demonstrated their potential for: (i) protecting, as a membrane, the site of nerve crush or repair by end-to-end surgery and avoiding post-operative nerve adhesion; (ii) bridging, as a conduit, the two nerve stumps after a severe peripheral nerve lesion with substance loss. A 1 cm gap on rat median nerve was repaired using CS/DSP and CS/GPTMS_DSP conduits to further investigate their ability to induce nerve regeneration in vivo. CS/GPTMS_DSP tubes resulted to be more fragile during suturing and, along a 12 week post-operative lapse of time, they detached from the distal nerve stump. On the contrary CS/DSP conduits promoted nerve fiber regeneration and functional recovery, leading to an outcome comparable to median nerve repaired by autograft.
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Affiliation(s)
- F Fregnan
- Department of Clinical and Biological Sciences, and Cavalieri Ottolenghi Neuroscience Institute, University of Turin, Regione Gonzole 10, 10043 Orbassano, Italy
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24
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McCreedy DA, Margul DJ, Seidlits SK, Antane JT, Thomas RJ, Sissman GM, Boehler RM, Smith DR, Goldsmith SW, Kukushliev TV, Lamano JB, Vedia BH, He T, Shea LD. Semi-automated counting of axon regeneration in poly(lactide co-glycolide) spinal cord bridges. J Neurosci Methods 2016; 263:15-22. [PMID: 26820904 DOI: 10.1016/j.jneumeth.2016.01.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 01/14/2016] [Accepted: 01/16/2016] [Indexed: 10/22/2022]
Abstract
BACKGROUND Spinal cord injury (SCI) is a debilitating event with multiple mechanisms of degeneration leading to life-long paralysis. Biomaterial strategies, including bridges that span the injury and provide a pathway to reconnect severed regions of the spinal cord, can promote partial restoration of motor function following SCI. Axon growth through the bridge is essential to characterizing regeneration, as recovery can occur via other mechanisms such as plasticity. Quantitative analysis of axons by manual counting of histological sections can be slow, which can limit the number of bridge designs evaluated. In this study, we report a semi-automated process to resolve axon numbers in histological sections, which allows for efficient analysis of large data sets. NEW METHOD Axon numbers were estimated in SCI cross-sections from animals implanted with poly(lactide co-glycolide) (PLG) bridges with multiple channels for guiding axons. Immunofluorescence images of histological sections were filtered using a Hessian-based approach prior to threshold detection to improve the signal-to-noise ratio and filter out background staining associated with PLG polymer. RESULTS Semi-automated counting successfully recapitulated average axon densities and myelination in a blinded PLG bridge implantation study. COMPARISON WITH EXISTING METHODS Axon counts obtained with the semi-automated technique correlated well with manual axon counts from blinded independent observers across sections with a wide range of total axons. CONCLUSIONS This semi-automated detection of Hessian-filtered axons provides an accurate and significantly faster alternative to manual counting of axons for quantitative analysis of regeneration following SCI.
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Affiliation(s)
- Dylan A McCreedy
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Daniel J Margul
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Stephanie K Seidlits
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA; Department of Bioengineering, University of California Los Angeles, Los Angeles, CA, USA
| | - Jennifer T Antane
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA
| | - Ryan J Thomas
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Gillian M Sissman
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Ryan M Boehler
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA
| | - Dominique R Smith
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA
| | - Sam W Goldsmith
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA
| | - Todor V Kukushliev
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA
| | - Jonathan B Lamano
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA
| | - Bansi H Vedia
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA
| | - Ting He
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA
| | - Lonnie D Shea
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA.
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25
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Suzuki H, Araki K, Matsui T, Tomifuji M, Yamashita T, Kobayashi Y, Shiotani A. Value of a novel PGA-collagen tube on recurrent laryngeal nerve regeneration in a rat model. Laryngoscope 2015; 126:E233-9. [PMID: 26525485 DOI: 10.1002/lary.25750] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Revised: 08/13/2015] [Accepted: 09/15/2015] [Indexed: 11/11/2022]
Abstract
OBJECTIVES/HYPOTHESIS Nerbridge (Toyobo Co., Ltd., Osaka, Japan) is a novel polyglycolic acid (PGA) tube that is filled with collagen fibers and that facilitates nerve fiber expansion and blood vessel growth. It is biocompatible and commercially available, with governmental approval for practical use in Japan. We hypothesized that the PGA-collagen tube would promote regeneration of the recurrent laryngeal nerve (RLN). This hypothesis was examined in a rat axotomy model of the RLN. STUDY DESIGN Prospective animal study. METHODS The axotomy model was established by transection of the left RLN in adult Sprague-Dawley rats. The cut ends of the nerve were bridged using Nerbridge (Toyobo Co., Ltd.) with a 1-mm gap (tube-treatment group) or direct sutures (sutured-control group). Left vocal fold mobility, nerve conduction velocity, morphology, and histology were assessed after 15 weeks. RESULTS Fifteen weeks after treatment, nerve fiber connections were observed macroscopically in both groups, and more clear myelinated fibers and better prevention of laryngeal muscle atrophy were observed in the tube-treatment group compared with the sutured-control group. However, vocal fold movement recovery was not observed in either group, and the conduction velocity of the RLN did not differ between the two groups. CONCLUSIONS Better nerve regeneration was observed in the tube-treatment group. The combination therapy with molecular or gene therapy might be an effective strategy to improve vocal fold movement. The PGA-collagen tube has the potential to promote regeneration of the RLN and to be a scaffold for drug administration in these combination therapies. LEVEL OF EVIDENCE N/A. Laryngoscope, 126:E233-E239, 2016.
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Affiliation(s)
- Hiroshi Suzuki
- Department of Otolaryngology-Head and Neck Surgery, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Koji Araki
- Department of Otolaryngology-Head and Neck Surgery, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Toshiyasu Matsui
- Department of Anatomy and Neurobiology, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Masayuki Tomifuji
- Department of Otolaryngology-Head and Neck Surgery, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Taku Yamashita
- Department of Otolaryngology-Head and Neck Surgery, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Yasushi Kobayashi
- Department of Anatomy and Neurobiology, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Akihiro Shiotani
- Department of Otolaryngology-Head and Neck Surgery, National Defense Medical College, Tokorozawa, Saitama, Japan
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26
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Ronchi G, Raimondo S, Geuna S, Gambarotta G. New insights on the standardization of peripheral nerve regeneration quantitative analysis. Neural Regen Res 2015; 10:707-9. [PMID: 26109940 PMCID: PMC4468757 DOI: 10.4103/1673-5374.156962] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/28/2015] [Indexed: 01/03/2023] Open
Affiliation(s)
- Giulia Ronchi
- Department of Clinical and Biological Sciences, University of Torino, Orbassano (To), Italy ; Neuroscience Institute Cavalieri Ottolenghi (NICO), Orbassano (To), Italy
| | - Stefania Raimondo
- Department of Clinical and Biological Sciences, University of Torino, Orbassano (To), Italy ; Neuroscience Institute Cavalieri Ottolenghi (NICO), Orbassano (To), Italy
| | - Stefano Geuna
- Department of Clinical and Biological Sciences, University of Torino, Orbassano (To), Italy ; Neuroscience Institute Cavalieri Ottolenghi (NICO), Orbassano (To), Italy ; Neuroscience Institute of Torino (NIT), Interdepartmental Centre of Advanced Studies in Neuroscience, University of Torino, Italy
| | - Giovanna Gambarotta
- Department of Clinical and Biological Sciences, University of Torino, Orbassano (To), Italy ; Neuroscience Institute of Torino (NIT), Interdepartmental Centre of Advanced Studies in Neuroscience, University of Torino, Italy
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Christensen MB, Tresco PA. Differences Exist in the Left and Right Sciatic Nerves of Naïve Rats and Cats. Anat Rec (Hoboken) 2015; 298:1492-501. [PMID: 25857635 DOI: 10.1002/ar.23161] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Revised: 02/02/2015] [Accepted: 02/09/2015] [Indexed: 12/14/2022]
Abstract
The sciatic nerve of rats and cats is commonly used in experimental models of peripheral nerve injury and repair, as well as experiments involving peripheral nerve electrode implantation. In such experiments, morphometric parameters from the implanted nerve are commonly evaluated and compared to control values obtained from the contralateral nerves. However, this may not be an appropriate approach as differences may naturally exist in the structure of the two nerves owing to developmental or behavioral asymmetry. Additionally, in the cat, baseline values for standard morphometric parameters are not well established. In this study, we characterized fascicle area, fiber count, fiber density, fiber packing, mean g-ratio, and fiber diameter distributions in the rat and cat, as well as investigated the potential for naturally occurring sided differences in these parameters in both species. We also investigated whether animal age or location along the nerve influenced these parameters. We found that sided or left/right leg differences exist in some parameters in both the rat and the cat, calling into question the validity of using the contralateral nerve as a control. We also found that animal age and location along the nerve can make significant differences in the parameters tested, establishing the importance of using control nerves from age- and behaviorally matched animals whose morphometric parameters are collected and compared from the same location.
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Affiliation(s)
- Michael B Christensen
- Department of Bioengineering, College of Engineering, University of Utah, Salt Lake City, Utah
| | - Patrick A Tresco
- Department of Bioengineering, College of Engineering, University of Utah, Salt Lake City, Utah
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Geuna S, Herrera-Rincon C. Update on stereology for light microscopy. Cell Tissue Res 2015; 360:5-12. [PMID: 25743692 DOI: 10.1007/s00441-015-2143-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2014] [Accepted: 01/30/2015] [Indexed: 01/28/2023]
Abstract
The quantitative investigation of images taken from light microscopy observation is one of the pillars of biological and biomedical investigation. The main objective is the count of objects, usually cells. In addition, the measurement of several morphological parameters, such as the diameter of cells, the length of vessels, etc., can also be important for the quantitative assessment of the features of a tissue. Whereas counting and measuring histological elements may appear easy, especially today with the availability of dedicated software, in fact it is not, since what we can count and measure on light microscopy images are not the true histological elements but actually profiles of them. Obviously, the number and size of profiles of an object do not correspond to the object number and size and thus significant mistakes can be made in the interpretation of the quantitative data obtained from profiles. To cope with this problem, over the last decades, a number of design-based stereological tools have been developed in order to obtain unbiased and reliable quantitative estimates of cell and tissue elements that originate from light microscopy images. This paper reviews the basic principles of the stereological tools from the first disector applications through some of the most recently devised methods.
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Affiliation(s)
- Stefano Geuna
- Neuroscience Institute of the Cavalieri Ottolenghi Foundation & Department of Clinical and Biological Sciences, University of Turin, Turin, Italy,
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29
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Herculano-Houzel S, von Bartheld CS, Miller DJ, Kaas JH. How to count cells: the advantages and disadvantages of the isotropic fractionator compared with stereology. Cell Tissue Res 2015; 360:29-42. [PMID: 25740200 DOI: 10.1007/s00441-015-2127-6] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 01/15/2015] [Indexed: 01/12/2023]
Abstract
The number of cells comprising biological structures represents fundamental information in basic anatomy, development, aging, drug tests, pathology and genetic manipulations. Obtaining unbiased estimates of cell numbers, however, was until recently possible only through stereological techniques, which require specific training, equipment, histological processing and appropriate sampling strategies applied to structures with a homogeneous distribution of cell bodies. An alternative, the isotropic fractionator (IF), became available in 2005 as a fast and inexpensive method that requires little training, no specific software and only a few materials before it can be used to quantify total numbers of neuronal and non-neuronal cells in a whole organ such as the brain or any dissectible regions thereof. This method entails transforming a highly anisotropic tissue into a homogeneous suspension of free-floating nuclei that can then be counted under the microscope or by flow cytometry and identified morphologically and immunocytochemically as neuronal or non-neuronal. We compare the advantages and disadvantages of each method and provide researchers with guidelines for choosing the best method for their particular needs. IF is as accurate as unbiased stereology and faster than stereological techniques, as it requires no elaborate histological processing or sampling paradigms, providing reliable estimates in a few days rather than many weeks. Tissue shrinkage is also not an issue, since the estimates provided are independent of tissue volume. The main disadvantage of IF, however, is that it necessarily destroys the tissue analyzed and thus provides no spatial information on the cellular composition of biological regions of interest.
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Affiliation(s)
- Suzana Herculano-Houzel
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil,
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Ramkumar M, Sharma S, Jacob TG, Bhardwaj DN, Nag TC, Roy TS. The human trochlear and abducens nerves at different ages - a morphometric study. Aging Dis 2015; 6:6-16. [PMID: 25657848 DOI: 10.14336/ad.2014.0310] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 02/21/2014] [Accepted: 03/10/2014] [Indexed: 11/01/2022] Open
Abstract
The trochlear and abducens nerves (TN and AN) control the movement of the superior oblique and lateral rectus muscles of the eyeball, respectively. Despite their immense clinical and radiological importance no morphometric data was available from a wide spectrum of age groups for comparison with either pathological or other conditions involving these nerves. In the present study, morphometry of the TN and AN was performed on twenty post-mortem samples ranging from 12-90 years of age. The nerve samples were processed for resin embedding and toluidine blue stained thin (1µm) sections were used for estimating the total number of myelinated axons by fractionator and the cross sectional area of the nerve and the axons by point counting methods. We observed that the TN was covered by a well-defined epineurium and had ill-defined fascicles, whereas the AN had multiple fascicles with scanty epineurium. Both nerves contained myelinated and unmyelinated fibers of various sizes intermingled with each other. Out of the four age groups (12-20y, 21-40y, 41-60y and >61y) the younger groups revealed isolated bundles of small thinly myelinated axons. The total number of myelinated fibers in the TN and AN at various ages ranged from 1100-3000 and 1600-7000, respectively. There was no significant change in the cross-sectional area of the nerves or the axonal area of the myelinated nerves across the age groups. However, myelin thickness increased significantly in the AN with aging (one way ANOVA). The present study provides baseline morphometric data on the human TN and AN at various ages.
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Affiliation(s)
- Muthu Ramkumar
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi-110608, India
| | - Saroj Sharma
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi-110608, India
| | - Tony G Jacob
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi-110608, India
| | - Daya N Bhardwaj
- Department of Forensic Medicine, All India Institute of Medical Sciences, New Delhi-110608, India
| | - Tapas C Nag
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi-110608, India
| | - Tara Sankar Roy
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi-110608, India
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Geuna S. The sciatic nerve injury model in pre-clinical research. J Neurosci Methods 2015; 243:39-46. [PMID: 25629799 DOI: 10.1016/j.jneumeth.2015.01.021] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 01/15/2015] [Accepted: 01/16/2015] [Indexed: 12/15/2022]
Abstract
In the pre-clinical view, the study of peripheral nerve repair and regeneration still needs to be carried out in animal models due to the structural complexity of this organ which can be only partly simulated in vitro. The far most used experimental model is based on the injury of the sciatic nerve, the largest nerve trunk in mammals. In this paper, the potential application of the sciatic nerve injury model in pre-clinical research is critically reviewed. This paper is aimed at helping researchers in properly employing this in vivo model for the study of nerve repair and regeneration as well as interpreting the results in a clinical translation perspective.
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Affiliation(s)
- Stefano Geuna
- Neuroscience Institute of the Cavalieri Ottolenghi Foundation & Department of Clinical and Biological Sciences, University of Turin, Italy.
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Ronchi G, Jager SB, Vaegter CB, Raimondo S, Giacobini-Robecchi MG, Geuna S. Discrepancies in quantitative assessment of normal and regenerated peripheral nerve fibers between light and electron microscopy. J Peripher Nerv Syst 2015; 19:224-33. [DOI: 10.1111/jns.12090] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 06/06/2014] [Accepted: 07/31/2014] [Indexed: 01/24/2023]
Affiliation(s)
- Giulia Ronchi
- Department of Clinical and Biological Sciences; University of Turin; Turin Italy
- Neuroscience Institute of the “Cavalieri Ottolenghi” Foundation (NICO); University of Turin; Turin Italy
| | - Sara Buskbjerg Jager
- Danish Research Institute of Translational Neuroscience DANDRITE, Nordic EMBL Partnership, and The Lundbeck Foundation Research Center MIND, Department of Biomedicine; Aarhus University; Aarhus Denmark
| | - Christian Bjerggaard Vaegter
- Danish Research Institute of Translational Neuroscience DANDRITE, Nordic EMBL Partnership, and The Lundbeck Foundation Research Center MIND, Department of Biomedicine; Aarhus University; Aarhus Denmark
| | - Stefania Raimondo
- Department of Clinical and Biological Sciences; University of Turin; Turin Italy
- Neuroscience Institute of the “Cavalieri Ottolenghi” Foundation (NICO); University of Turin; Turin Italy
| | | | - Stefano Geuna
- Department of Clinical and Biological Sciences; University of Turin; Turin Italy
- Neuroscience Institute of the “Cavalieri Ottolenghi” Foundation (NICO); University of Turin; Turin Italy
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Schaakxs D, Kalbermatten DF, Pralong E, Raffoul W, Wiberg M, Kingham PJ. Poly-3-hydroxybutyrate strips seeded with regenerative cells are effective promoters of peripheral nerve repair. J Tissue Eng Regen Med 2015; 11:812-821. [DOI: 10.1002/term.1980] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 08/17/2014] [Accepted: 11/26/2014] [Indexed: 12/21/2022]
Affiliation(s)
- Dominique Schaakxs
- Department of Integrative Medical Biology; Umeå University; Sweden
- Division of Plastic, Reconstructive and Aesthetic Surgery, CHUV; University Hospital of Lausanne; Switzerland
| | - Daniel F. Kalbermatten
- Department of Plastic, Reconstructive and Aesthetic Surgery; University Hospital of Basel; Switzerland
| | - Etienne Pralong
- Department of Neurosurgery; University Hospital of Lausanne; Switzerland
| | - Wassim Raffoul
- Division of Plastic, Reconstructive and Aesthetic Surgery, CHUV; University Hospital of Lausanne; Switzerland
| | - Mikael Wiberg
- Department of Integrative Medical Biology; Umeå University; Sweden
- Department of Surgical and Perioperative Sciences; Umeå University; Sweden
| | - Paul J. Kingham
- Department of Integrative Medical Biology; Umeå University; Sweden
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Liśkiewicz A, Właszczuk A, Gendosz D, Larysz-Brysz M, Kapustka B, Łączyński M, Lewin-Kowalik J, Jędrzejowska-Szypułka H. Sciatic nerve regeneration in rats subjected to ketogenic diet. Nutr Neurosci 2014; 19:116-24. [PMID: 25401509 DOI: 10.1179/1476830514y.0000000163] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVES Ketogenic diet (KD) is a high-fat-content diet with insufficiency of carbohydrates that induces ketogenesis. Besides its anticonvulsant properties, many studies have shown its neuroprotective effect in central nervous system, but its influence on peripheral nervous system has not been studied yet. We examined the influence of KD on regeneration of peripheral nerves in adult rats. METHODS Fifty one rats were divided into three experimental (n = 15) and one control (n = 6) groups. Right sciatic nerve was crushed and animals were kept on standard (ST group) or ketogenic diet, the latter was introduced 3 weeks before (KDB group) or on the day of surgery (KDA group). Functional (CatWalk) tests were performed once a week, and morphometric (fiber density, axon diameter, and myelin thickness) analysis of the nerves was made after 6 weeks. Body weight and blood ketone bodies level were estimated at the beginning and the end of experiment. RESULTS Functional analysis showed no differences between groups. Morphometric evaluation showed most similarities to the healthy (uncrushed) nerves in KDB group. Nerves in ST group differed mostly from all other groups. Ketone bodies were elevated in both KD groups, while post-surgery animals' body weight was lower as compared to ST group. DISCUSSION Regeneration of sciatic nerves was improved in KD - preconditioned rats. These results suggest a neuroprotective effect of KD on peripheral nerves.
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Affiliation(s)
- Arkadiusz Liśkiewicz
- a Medical University of Silesia, School of Medicine in Katowice , Department of Physiology , Poland
| | - Adam Właszczuk
- a Medical University of Silesia, School of Medicine in Katowice , Department of Physiology , Poland
| | - Daria Gendosz
- a Medical University of Silesia, School of Medicine in Katowice , Department of Physiology , Poland
| | - Magdalena Larysz-Brysz
- a Medical University of Silesia, School of Medicine in Katowice , Department of Physiology , Poland
| | - Bartosz Kapustka
- a Medical University of Silesia, School of Medicine in Katowice , Department of Physiology , Poland
| | - Mariusz Łączyński
- a Medical University of Silesia, School of Medicine in Katowice , Department of Physiology , Poland
| | - Joanna Lewin-Kowalik
- a Medical University of Silesia, School of Medicine in Katowice , Department of Physiology , Poland
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35
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Miller NR, Johnson MA, Nolan T, Guo Y, Bernstein AM, Bernstein SL. Sustained neuroprotection from a single intravitreal injection of PGJ₂ in a nonhuman primate model of nonarteritic anterior ischemic optic neuropathy. Invest Ophthalmol Vis Sci 2014; 55:7047-56. [PMID: 25298416 DOI: 10.1167/iovs.14-14063] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
PURPOSE Prostaglandin J₂ (PGJ₂) is neuroprotective in a murine model of nonarteritic anterior ischemic optic neuropathy (NAION). After assessing for potential toxicity, we evaluated the efficacy of a single intravitreal (IVT) injection of PGJ₂ in a nonhuman primate model of NAION (pNAION). METHODS We assessed PGJ₂ toxicity by administering it as a single high-dose intravenous (IV) injection, consecutive daily high-dose IV injections, or a single IVT injection in one eye of five adult rhesus monkeys. To assess efficacy, we induced pNAION in one eye of five adult male rhesus monkeys using a laser-activated rose bengal induction method. We then injected the eye with either PGJ₂ or phosphate-buffered saline (PBS) intravitreally immediately or 5 hours post induction. We performed a clinical assessment, optical coherence tomography, electrophysiological testing, fundus photography, and fluorescein angiography in all animals prior to induction and at 1 day, 1 week, 2 weeks, and 4 weeks after induction. Following analysis of the first eye, we induced pNAION in the contralateral eye and then injected either PGJ₂ or PBS. We euthanized all animals 5 weeks after final assessment of the fellow eye and performed both immunohistochemical and light and electron microscopic analyses of the retina and optic nerves. RESULTS TOXICITY PGJ₂ caused no permanent systemic toxicity regardless of the amount injected or route of delivery, and there was no evidence of any ocular toxicity with the dose of PGJ₂ used in efficacy studies. Transient reduction in the amplitudes of the visual evoked potentials and the N95 component of the pattern electroretinogram (PERG) occurred after both IV and IVT administration of high doses of PGJ₂; however, the amplitudes returned to normal in all animals within 1 week. EFFICACY In all eyes, a single IVT dose of PGJ₂ administered immediately or shortly after induction of pNAION resulted in a significant reduction of clinical, electrophysiological, and histological damage compared with vehicle-injected eyes (P = 0.03 for both VEP and PERG; P = 0.05 for axon counts). CONCLUSIONS In nonhuman primates, PGJ₂ administered either intravenously or intravitreally produces no permanent toxicity at even four times the dose given for neuroprotection. Additionally, a single IVT dose of PGJ₂ is neuroprotective when administered up to 5 hours after induction of pNAION.
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Affiliation(s)
- Neil R Miller
- Wilmer Eye Institute, the Johns Hopkins Medical Institutions, Baltimore, Maryland, United States Department of Ophthalmology and Visual Science, University of Maryland Medical Center, Baltimore, Maryland, United States
| | - Mary A Johnson
- Department of Ophthalmology and Visual Science, University of Maryland Medical Center, Baltimore, Maryland, United States
| | - Theresa Nolan
- Department of Veterinary Resources, University of Maryland Medical Center, Baltimore, Maryland, United States
| | - Yan Guo
- Department of Ophthalmology and Visual Science, University of Maryland Medical Center, Baltimore, Maryland, United States
| | - Alexander M Bernstein
- Department of Ophthalmology and Visual Science, University of Maryland Medical Center, Baltimore, Maryland, United States
| | - Steven L Bernstein
- Department of Ophthalmology and Visual Science, University of Maryland Medical Center, Baltimore, Maryland, United States
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36
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The mouse median nerve experimental model in regenerative research. BIOMED RESEARCH INTERNATIONAL 2014; 2014:701682. [PMID: 25180190 PMCID: PMC4142669 DOI: 10.1155/2014/701682] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 07/23/2014] [Accepted: 07/25/2014] [Indexed: 01/12/2023]
Abstract
Sciatic nerve crush injury in rat animal model is one of the most common experimental models used in regenerative research. However, the availability of transgenic mouse for nerve regeneration studies is constantly increasing and, therefore, the shift from rat model to mouse model is, in some cases, necessary. Moreover, since most of the human nerve lesions occur in the upper limb, it is also advantageous to shift from sciatic nerve to median nerve. In this study we described an experimental model which involves lesions of the median nerve in the mouse. Data showed that the finger flexor muscle contraction strength, assessed to evaluate the motor function recovery, and reached values not different from the control already 20 days after injury. The degree of nerve regeneration evaluated with stereological methods in light microscopy showed that, 25 days after injury, the number of regenerated myelinated fibers was comparable to the control, but they were smaller with a thinner myelin thickness. Stereological analysis made in electron microscopy confirmed these results, although the total number of fibers quantified was significantly higher compared to light microscopy analysis, due to the very small size of some fibers that can be detected only in electron microscopy.
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Ozay R, Uzar E, Aktas A, Uyar ME, Gürer B, Evliyaoglu O, Cetinalp NE, Turkay C. The role of oxidative stress and inflammatory response in high-fat diet induced peripheral neuropathy. J Chem Neuroanat 2014; 55:51-7. [PMID: 24407112 DOI: 10.1016/j.jchemneu.2013.12.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Revised: 12/25/2013] [Accepted: 12/27/2013] [Indexed: 12/17/2022]
Abstract
OBJECTIVE Earlier studies suggest that high-calorie diet is an important risk factor for neuronal damage resulting from oxidative stress of lipid metabolism. In our experimental study of rats under high-fat diet, oxidative stress markers and axonal degeneration parameters were used to observe the sciatic nerve neuropathy. The aim of this study is to evaluate the pathophysiology of neuropathy induced by high-fat diet. METHODS A total of 14 male rats (Wistar albino) were randomly divided into two experimental groups as follows; control group (n=7) and the model group (n=7); while control group was fed with standard diet; where the model group was fed with a high-fat diet for 12 weeks. At the end of 12 weeks, the lipid profile and blood glucose levels, interleukin-1β (IL-1), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and transforming growth factor-β (TGF-β) levels were studied. Tissue malondialdehyde (MDA), nitric oxide (NO) levels and super-oxide dismutase (SOD), paraoxonase-1 (PON-1) and glutathione peroxidase (GPx) activities were studied. The distal blocks of the left sciatic nerves were evaluated for histomorphological analysis (including mean axon area, axon numbers, nerve fiber diameters, axon diameters, and thickness of myelin sheets). RESULTS Body weights, serum glucose and high-density lipoprotein (HDL) levels of rats were found not statistically significantly different compared between the model and the control groups (p>0.05). Serum cholesterol, triglyceride, TGF-β and TNF-α levels were significantly higher in the model group when compared with the control group (p<0.05). IL-1 and IL-6 levels were not statistically significantly different compared between the model group and the control group (p>0.05). The MDA and NO levels and the SOD and GPx activities of the sciatic nerves in model group were statistically significantly higher than the control group (p<0.05). In addition, the activities of PON-1 were statistically significantly lower in the model group when compared with the control group (p<0.05). The difference in the total number of myelinated axons between the control group and the model group was not statistically significant (p>0.05). The nerve fiber diameter and the thickness of the myelin sheet were statistically significantly lower in the model group when compared with the control group (p<0.05). The axon diameter and area were significantly decreased in the model group when compared with the control group (p<0.05). CONCLUSION Our results support that dyslipidemia is an independent risk factor for the development of neuropathy. In addition, we postulated that oxidative stress and inflammatory response may play an important role in the pathogenesis of high-fat diet induced neuropathy.
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Affiliation(s)
- Rafet Ozay
- Ministry of Health, Diskapi Yildirim Beyazit Education and Research Hospital, Neurosurgery Clinic, Turkey
| | - Ertugrul Uzar
- Dicle University, Department of Neurology, School of Medicine, Diyarbakır, Turkey
| | - Abit Aktas
- Istanbul University, Faculty of Veterinary Medicine, Department of Histology and Embriology, Istanbul, Turkey
| | - Mehtap Erkmen Uyar
- Başkent University, Medical School, Department of Nephrology, Ankara, Turkey
| | - Bora Gürer
- Ministry of Health, Diskapi Yildirim Beyazit Education and Research Hospital, Neurosurgery Clinic, Turkey.
| | - Osman Evliyaoglu
- Dicle University, Department of Biochemistry, School of Medicine, Diyarbakır, Turkey
| | - Nuri Eralp Cetinalp
- Etlik Ihtisas Research and Educational Hospital, Department of Neurosurgery, Ankara, Turkey
| | - Cansel Turkay
- Fatih University, Department of Gastroenterology, School of Medicine, Ankara, Turkey
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Piskin A, Altunkaynak BZ, Çitlak A, Sezgin H, Yazιcι O, Kaplan S. Immediate versus delayed primary nerve repair in the rabbit sciatic nerve. Neural Regen Res 2013; 8:3410-5. [PMID: 25206663 PMCID: PMC4146006 DOI: 10.3969/j.issn.1673-5374.2013.36.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Accepted: 11/23/2013] [Indexed: 11/18/2022] Open
Abstract
It is well known that peripheral nerve injury should be treated immediately in the clinic, but in some instances, repair can be delayed. This study investigated the effects of immediate versus delayed (3 days after injury) neurorrhaphy on repair of transected sciatic nerve in New Zealand rabbits using stereological, histomorphological and biomechanical methods. At 8 weeks after immediate and delayed neurorrhaphy, axon number and area in the sciatic nerve, myelin sheath and epineurium thickness, Schwann cell morphology, and the mechanical property of nerve fibers did not differ obviously. These results indicate that delayed neurorrhaphy do not produce any deleterious effect on sciatic nerve repair.
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Affiliation(s)
- Ahmet Piskin
- Department of Orthopedics and Traumatology, School of Medicine, Ondokuz Mayıs University, Samsun, Turkey
| | - Berrin Zühal Altunkaynak
- Department of Histology and Embryology, School of Medicine, Ondokuz Mayıs University, Samsun, Turkey
| | - Atilla Çitlak
- Department of Orthopedics and Traumatology, School of Medicine, Giresun University, Giresun, Turkey
| | - Hicabi Sezgin
- Department of Orthopedics and Traumatology, School of Medicine, Ondokuz Mayıs University, Samsun, Turkey
| | - Ozgür Yazιcι
- Department of Orthopedics and Traumatology, School of Medicine, Ondokuz Mayıs University, Samsun, Turkey
| | - Süleyman Kaplan
- Department of Histology and Embryology, School of Medicine, Ondokuz Mayıs University, Samsun, Turkey
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Bahney J, von Bartheld CS. Validation of the isotropic fractionator: comparison with unbiased stereology and DNA extraction for quantification of glial cells. J Neurosci Methods 2013; 222:165-74. [PMID: 24239779 DOI: 10.1016/j.jneumeth.2013.11.002] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2013] [Revised: 11/01/2013] [Accepted: 11/03/2013] [Indexed: 11/16/2022]
Abstract
BACKGROUND The "isotropic fractionator" (IF) is a novel cell counting technique that homogenizes fixed tissue, recovers cell nuclei in solution, and samples and quantifies nuclei by extrapolation. Studies using this technique indicate that the ratio of glia to neurons in the human brain is approximately 1:1 rather than the 10:1 or 50:1 ratio previously assumed. Although some results obtained with the IF have been similar to those obtained by stereology, the IF has never been calibrated or validated. It is conceivable that only a fraction of glial cell nuclei are recovered intact or recognized after the homogenization step. NEW METHOD To rule out this simple explanation for the claim of a 1:1 glia-neuron ratio, we compared cell numbers obtained from adjacent, weight-normalized samples of human and macaque monkey white matter using three techniques: the IF, unbiased stereology of histological sections in exhaustively sectioned samples, and cell numbers calculated from DNA extraction. RESULTS AND COMPARISON OF METHODS In primate forebrains, the IF yielded 73,000-90,000 nuclei/mg white matter, unbiased stereology yielded 75,000-92,000 nuclei/mg, with coefficients of error ranging from 0.013 to 0.063, while DNA extraction yielded only 4000-23,000 nuclei/mg in fixed white matter tissues. CONCLUSIONS Since the IF revealed about 100% of the numbers produced by unbiased stereology, there is no significant underestimate of glial cells. This confirms the notion that the human brain overall contains glial cells and neurons with a ratio of about 1:1 - far from the originally assumed ratio of 10:1 in favor of glial cells.
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Affiliation(s)
- Jami Bahney
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV 89557, USA
| | - Christopher S von Bartheld
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV 89557, USA.
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Çolakoğlu S, Aktaş A, Raimondo S, Türkmen AP, Altunkaynak BZ, Odacı E, Geuna S, Kaplan S. Effects of prenatal exposure to diclofenac sodium and saline on the optic nerve of 4- and 20-week-old male rats: a stereological and histological study. Biotech Histochem 2013; 89:136-44. [DOI: 10.3109/10520295.2013.827741] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
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Therapeutic effect of exendin-4, a long-acting analogue of glucagon-like peptide-1 receptor agonist, on nerve regeneration after the crush nerve injury. BIOMED RESEARCH INTERNATIONAL 2013; 2013:315848. [PMID: 23984340 PMCID: PMC3747455 DOI: 10.1155/2013/315848] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 07/11/2013] [Accepted: 07/14/2013] [Indexed: 12/27/2022]
Abstract
Glucagon-like peptide-1 (GLP-1) is glucose-dependent insulinotropic hormone secreted from enteroendocrine L cells. Its long-acting analogue, exendin-4, is equipotent to GLP-1 and is used to treat type 2 diabetes mellitus. In addition, exendin-4 has effects on the central and peripheral nervous system. In this study, we administered repeated intraperitoneal (i.p.) injections of exendin-4 to examine whether exendin-4 is able to facilitate the recovery after the crush nerve injury. Exendin-4 injection was started immediately after crush injury and was repeated every day for subsequent 14 days. Rats subjected to sciatic nerve crush exhibited marked functional loss, electrophysiological dysfunction, and atrophy of the tibialis anterior muscle (TA). All these changes, except for the atrophy of TA, were improved significantly by the administration of exendin-4. Functional, electrophysiological, and morphological parameters indicated significant enhancement of nerve regeneration 4 weeks after nerve crush. These results suggest that exendin-4 is feasible for clinical application to treat peripheral nerve injury.
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Experimental model for the study of the effects of platelet-rich plasma on the early phases of muscle healing. BLOOD TRANSFUSION = TRASFUSIONE DEL SANGUE 2013; 12 Suppl 1:s221-8. [PMID: 23867182 DOI: 10.2450/2013.0275-12] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 03/12/2013] [Indexed: 01/19/2023]
Abstract
BACKGROUND There is abundant evidence suggesting that growth factors may play a key role in the healing process, especially in the early stages of inflammation. Despite the reported clinical successes with the use of growth factors there is still a lack of knowledge on the biological mechanism underlying the activity of platelet-rich plasma during the process of muscle healing. The aim of this study was to analyse the early effects of platelet- rich plasma in an easily reproducible animal model. MATERIALS AND METHODS Wistar male adult rats (n=102) were used in this study. The muscle lesion was created with a scalpel in the flexor sublimis muscles. Platelet-rich plasma was applied immediately after surgery. Treated, untreated and contralateral muscles were analysed by morphological evaluation and western blot assay. RESULTS Leucocyte infiltration was significantly greater in muscles treated with platelet-rich plasma than in both untreated and contralateral muscles. The latter showed greater leucocyte infiltration when compared to the untreated muscles. Platelet-rich plasma treatment also modified the cellular composition of the leucocyte infiltration leading to increased expression of CD3, CD8, CD19 and CD68 and to decreased CD4 antigen expression in both platelet-rich plasma treated and contralateral muscles. Blood vessel density and blood vessel diameters were not statistically significantly different between the three groups analysed. DISCUSSION The results of this study showed that treatment with platelet-rich plasma magnified the physiological early inflammatory response following a muscle injury, modifying the pattern of cellular recruitment. Local platelet-rich plasma treatment may exert a direct or, more plausibly, indirect systemic effect on healing processes, at least in the earliest inflammatory phase.
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A novel combined imaging/morphometrical method for the analysis of human sural nerve biopsies for clinical diagnosis. Methods Mol Biol 2013; 931:391-411. [PMID: 23027013 DOI: 10.1007/978-1-62703-056-4_19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Nerve Morphometry is one tool employed in the clinical assessment of peripheral sural nerve pathological abnormalities. A new method is presented in this chapter incorporating an unbiased approach to quantitative sural nerve evaluation. Using conventional epoxy embedded nerves processed for electron microscopy, confocal microscopy, and interactive digital assessment, this method produces a rigorous, accurate reproducible record for use in clinical diagnosis.
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Caner B, Kafa MI, Bekar A, Kurt MA, Karli N, Cansev M, Ulus IH. Intraperitoneal administration of CDP-choline or a combination of cytidine plus choline improves nerve regeneration and functional recovery in a rat model of sciatic nerve injury. Neurol Res 2012; 34:238-45. [PMID: 22449436 DOI: 10.1179/1743132812y.0000000003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
OBJECTIVE Topical cytidine-5'-diphosphocholine (CDP-choline) improves functional recovery and promotes nerve regeneration in sciatic nerve injury in rats. The aims of this study were to test whether systemic treatment with CDP-choline was effective in improving the recovery of injured sciatic nerve, and to determine whether the cytidine and/or choline moieties of CDP-choline contribute to its beneficial actions. METHODS Seventy Sprague-Dawley rats underwent a surgical procedure that involved transectioning and immediate surgical repairing of the right sciatic nerve. Rats were assigned to one of five groups and administered intraperitoneally 1 ml/kg of saline (control) or saline containing 600 μmol/kg of each of CDP-choline, cytidine, choline, or cytidine+choline. RESULTS Recovery in sciatic function index score was greater in rats treated with CDP-choline, choline, or cytidine+choline at 8 and 12 weeks after the interventions. Peripheral nerve regeneration evaluated by electromyography at 12 weeks was also greater in rats receiving CDP-choline (228% of control), choline (168% of control), or cytidine+choline (221% of control). Axon counts and axon density increased significantly following CDP-choline, choline, or cytidine+choline, respectively. Treatment with equivalent dose of cytidine failed to affect sciatic function index, electromyography, and axon counts. Treatment with CDP-choline, but not its metabolites improved nerve adherence and separability score. CONCLUSION These data show that intraperitoneal CDP-choline, as well as the combination of its metabolites, cytidine+choline, improves functional recovery and promotes regeneration of injured sciatic nerves in rats. CDP-choline also improves nerve adherence and separability.
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Affiliation(s)
- Basak Caner
- Department of Neurosurgery, Saglik Bakanligi Goztepe Egitim ve Arastirma Hastanesi, Istanbul, Turkey
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Kaplan S, Pişkin A, Ayyildiz M, Aktaş A, Köksal B, Ulkay MB, Türkmen AP, Bakan F, Geuna S. The effect of melatonin and platelet gel on sciatic nerve repair: an electrophysiological and stereological study. Microsurgery 2011; 31:306-13. [PMID: 21520268 DOI: 10.1002/micr.20876] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Accepted: 12/06/2010] [Indexed: 01/26/2023]
Abstract
Nerve regeneration after surgical reconstruction is far from optimal, and thus effective strategies for improving the outcome of nerve repair are being sought. In this experiment, we verified if postoperative intraperitoneal melatonin (MLT) administration after intraoperative platelet gel application improves peripheral nerve regeneration. In adult male rats, 1-cm long sciatic nerve defects were repaired using four different strategies: autologous nerve graft repair followed by MLT (NM, n = 5), collagen conduit repair followed by MLT (CM, n = 5), platelet gel-enriched collagen conduit repair followed by MLT (CGM, n = 6), and platelet gel-enriched collagen conduit (CG, n = 5) repair followed by no substance administration. Sham operated animals were used as controls (Cont, n = 5). Ninety days after surgery, the nerve regeneration outcome was comparatively assessed by means of electrophysiological and stereological analysis. Electrophysiology revealed no significant differences between the experimental and the sham control groups. Stereological analysis showed no significant differences among the experimental groups regarding axon size and myelin thickness, but the axon number was significantly lower in the CM compared to Cont and NM group. Moreover, there was no significant difference between number of axons in CG and Cont groups, between CGM and CM, and between CM and NM. Although it was observed that platelet gel have a positive effect on nerve regeneration, but a combination of local platelet gel with MLT does not have the same effect on nerve repair.
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Affiliation(s)
- Süleyman Kaplan
- Department of Histology and Embryology, Ondokuz Mayis University School of Medicine, Samsun, Turkey.
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Haastert-Talini K, Schaper-Rinkel J, Schmitte R, Bastian R, Mühlenhoff M, Schwarzer D, Draeger G, Su Y, Scheper T, Gerardy-Schahn R, Grothe C. In Vivo Evaluation of Polysialic Acid as Part of Tissue-Engineered Nerve Transplants. Tissue Eng Part A 2010; 16:3085-98. [DOI: 10.1089/ten.tea.2010.0180] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Kirsten Haastert-Talini
- Institute of Neuroanatomy, Hannover Medical School, Hannover, Germany
- Center for Systems Neurosciences (ZSN), Hannover, Germany
| | - Janett Schaper-Rinkel
- Institute of Neuroanatomy, Hannover Medical School, Hannover, Germany
- Center for Systems Neurosciences (ZSN), Hannover, Germany
| | - Ruth Schmitte
- Institute of Neuroanatomy, Hannover Medical School, Hannover, Germany
| | - Rode Bastian
- Institute of Technical Chemistry, University of Hannover, Hannover, Germany
| | - Martina Mühlenhoff
- Institute for Cellular Chemistry, Hannover Medical School, Hannover, Germany
| | - David Schwarzer
- Institute for Cellular Chemistry, Hannover Medical School, Hannover, Germany
| | - Gerald Draeger
- Institute of Organic Chemistry, University of Hannover, Hannover, Germany
| | - Yi Su
- Institute of Organic Chemistry, University of Hannover, Hannover, Germany
| | - Thomas Scheper
- Institute of Technical Chemistry, University of Hannover, Hannover, Germany
| | - Rita Gerardy-Schahn
- Center for Systems Neurosciences (ZSN), Hannover, Germany
- Institute for Cellular Chemistry, Hannover Medical School, Hannover, Germany
| | - Claudia Grothe
- Institute of Neuroanatomy, Hannover Medical School, Hannover, Germany
- Center for Systems Neurosciences (ZSN), Hannover, Germany
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