Nothwendigkeit einer feineren mechanischen Zerlegung des Gehirns und der Nerven vor der chemischen, dargestellt aus Beobachtungen

Ehrenberg, C.

doi:10.1002/andp.18331040702

Cited by 31 publications

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“…Ehrenberg was instrumental to the microscope revolution in Germany in the 1830s and felt compelled to mention the Berlin manufacturer: “Since the year 1834 I use a new and the strongest microscope from Pistor and Schiek and have therefore frequently confirmed and extended my observations”. Ehrenberg acknowledged van Leeuwenhoek’s anatomy, and (re)established the fibrillary nature of the nervous system in teased preparations (Ehrenberg, 1833). Ehrenberg had to create a new terminology besides the Latin word medulla ( Medullar-Substanz ) simply designating white matter since the 15th century.…”

Section: Before Myelin Was Myelinmentioning

confidence: 99%

“…The great merit of Ehrenberg was to suggest a continuity between gray and white matter, and between spine and peripheral nerves. But he conceived the nervous tubes similarly as van Leeuwenhoek vessels (Ehrenberg, 1833, pages 452–454): “The interior of varicose brain tubes is overall quite limpid, so that they could be held for transmitting mist or water … This milk color is absent in the cortical substance, which consists of the tips or beginnings of varicose brain tubes, and thus indeed possess the tube walls, but lack the voluminous contents thereof. From this it seems reasonable to conclude that the white color is inherent in particular to the content of the brain tube … The cylindrical simple nerve tubes, however, possess an essential difference from the structured brain tubes, for they have a much larger internal cavity, and enclosed there is a very noticeable, less transparent content which has long been recognized … By transverse section of each nerve its sinewy sheath … is of white color.…”

Section: Before Myelin Was Myelinmentioning

confidence: 99%

“…E: fresh frog spinal myelinated fiber: “a nerve tube with double wall containing the actual nerve marrow and the transparent structured brain tube which is quite transparent, emerging in β” (Fig. 11, Ehrenberg, 1833). F: two fresh myelinated fibers ( tubuli primitivi ) with axon emerging in right and slender organic fibers ( fibrae organicae ) with nuclei (Fig.…”

Section: Figmentioning

confidence: 99%

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The history of myelin

Boullerne

2016

Experimental Neurology

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Andreas Vesalius is attributed the discovery of white matter in the 16th century but van Leeuwenhoek is arguably the first to have observed myelinated fibers in 1717. A globular myelin theory followed, claiming all elements of the nervous system except for Fontana’s primitive cylinder with outer sheath in 1781. Remak’s axon revolution in 1836 relegated myelin to the unknown. Ehrenberg described nerve tubes with double borders in 1833, and Schwann with nuclei in 1839, but the medullary sheath acquired its name of myelin, coined by Virchow, only in 1854. Thanks to Schultze’s osmium specific staining in 1865, myelin designates the structure known today. The origin of myelin though was baffling. Only after Ranvier discovered a periodic segmentation, which came to us as nodes of Ranvier, did he venture suggesting in 1872 that the nerve internode was a fatty cell secreting myelin in cytoplasm. Ranvier’s hypothesis was met with high skepticism, because nobody could see the cytoplasm, and the term Schwann cell very slowly emerged into the vocabulary with von Lenhossék in 1895. When Cajal finally admitted the concept of Schwann cell internode in 1912, he still firmly believed myelin was secreted by the axon. Del Río-Hortega re-discovered oligodendrocytes in 1919 (after Robertson in 1899) and named them oligodendroglia in 1921, thereby antagonizing Cajal for discovering a second cell type in his invisible third element. Penfield had to come to del Río-Hortega’s rescue in 1924 for oligodendrocytes to be accepted. They jointly hypothesized myelin could be made by oligodendrocytes, considered the central equivalent of Schwann cells. Meanwhile myelin birefringence properties observed by Klebs in 1865 then Schmidt in 1924 confirmed its high fatty content, ascertained by biochemistry by Thudichum in 1884. The 20th century saw X-ray diffraction developed by Schmitt, who discovered in 1935 the crystal-like organization of this most peculiar structure, and devised the g-ratio concept in 1937. A revolution happened around the same time: saltatory conduction, the very reason for myelin existence, discovered by Tasaki in 1939 and confirmed by Huxley and Stämpfli in 1949. After the second world war, widely available electron microscopes allowed Geren to finally discover the origin of myelin in 1954, exactly a century after Virchow coined ‘myelin’ in 1854. Geren had the genial insight that the Schwann cell wraps around the axon and generates a spiral of compacted membrane–myelin. The central origin of myelin took a little longer due to the special configuration of oligodendrocyte distanced from the axon, but in 1962 the Bunges established the definitive proof that oligodendrocyte secretes myelin. The era of myelin biology had begun. In 1973 Norton devised a method to purify myelin which launched the modern molecular era.

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Section: Before Myelin Was Myelinmentioning

confidence: 99%

Section: Before Myelin Was Myelinmentioning

confidence: 99%

Section: Figmentioning

confidence: 99%

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The history of myelin

Boullerne

2016

Experimental Neurology

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“…In Ehrenberg's work, an early description of the nerve cell bodies in sympathetic ganglia is given (1833) [14]. Reil introduced the term "vegetative nervous system" in 1857 and thought that the rami communicantes are connections between the visceral and somatic system [15].…”

Section: History Of the Sympathetic Nervous Systemmentioning

confidence: 99%

The sympathetic trunk and its neural pathway to the upper limb: review of the literature

2005

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Zusammenfassung. Grundlagen: Kenntnisse der Anatomie des Truncus sympathicus und des autonomen Nervensystems sind von großer Bedeutung in der Sympathikuschirurgie. Allerdings existiert eine Vielzahl an unterschiedlichen sympathischen Nervenverbindungen zur oberen Extremität, wobei der Großteil im ersten Zwischenrippenraum zu liegen kommt. Aus unterschiedlichsten Gründen führt die chirurgische Sympathektomie im Bereich der oberen thorakalen Ganglien zu einer Unterbrechung der sympathischen Innervation der oberen Extremität. Entscheidend ist, diese variablen Verbindungen zu durchtrennen, um optimale chirurgische Ergebnisse zu erzielen.Methodik: Diese Arbeit basiert auf einer Durchsicht der Literatur der letzten 80 Jahre über die Anatomie des kranialen thorakalen Truncus sympathicus und seiner Verbindungen, die in der Sympathikuschirurgie von besonderer Bedeutung sind. Die Evaluation basiert auf einer Literaturrecherche in der Medline, ergänzt um Wissen aus Anatomiebüchern; es wird zudem eine Übersicht über die historische Entdeckung des sympathischen Systems gegeben.Ergebnisse: Zwei wichtige Ergebnisse liegen vor. 1. Intrathorakale Nervenverbindungen zwischen zweitem und erstem intrathorakalen Nerv dürften sympathische Fasern der oberen Extremität zuführen. Diese Verbindungen kommen bei mehr als 50 % der Menschen vor und dürften für Misserfolge und/oder Rezidive nach Sympathektomie verantwortlich sein.2. Aktuelle chirurgische Studien weisen darauf hin, dass das Hauptganglion für die sympathische Innervation der oberen Extremität im Segment T4 liegen könnte. Dies steht jedoch im Gegensatz zur bisher anerkannten Ansicht, dass das Hauptganglion der sympathischen Innervation für die obere Extremität das T2-Ganglion sei. Bislang können diese klinischen Erkenntnisse nicht durch anatomisches Wissen erklärt werden.Schlussfolgerungen: Profunde anatomische Kenntnisse sind eine unabdingbare Voraussetzung, um in der Sympathikuschirurgie optimale Ergebnisse zu erzielen.Schlüsselwörter: Truncus sympathicus, Thorakoskopie, Sympathektomie, Nervenverbindungen.Summary. Background: Knowledge of the anatomy of the sympathetic trunk and the autonomous nervous system is of great importance for sympathetic surgeons. However, a variety of different sympathetic pathways to the upper limb exist, most of them appearing in the first intercostal space. For several reasons, surgical sympathectomy of the upper thoracic ganglia interrupts the sympathetic innervation to the upper limb. It is crucial to reach these variable connections for gaining optimal surgical results.Methods: This paper is based on a review of the literature over a period of 80 years, concerning the anatomy of the upper thoracic sympathetic connections and their importance for surgical sympathectomy. The evaluation is based on research in Medline, broadened by knowledge of anatomical books; a review on the historical discovery of the sympathetic system is also provided.Results: There are two main findings.(1) Intrathoracic rami connecting the second and first thoracic nerve pr...

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“…In each he distinguished "four parallel lines, two of which form the external boundary lines, while the inner indicate the boundaries of the interior cavity" 7 . Cajal recognized in 1909 that the axis cylinder is the axonal process and that myelin sheath is external and a protective layer surrounding the axons.…”

Section: Introductionmentioning

confidence: 99%

Comparison of magnetization transfer methods for assessing macromolecular bound water in the brain and cervical spinal cord

Dopico

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Magnetization transfer (MT) imaging is a magnetic resonance imaging technique that generates contrast dependent upon the phenomenon of magnetization exchange between semi-solid macromolecular protons and water protons. This technique has the ability to indirectly image semi-solids, such as protein matrices and cell membranes, whose magnetization dies away too quickly to be imaged directly based on relaxation properties of water interacting with the semisolid lipid protons. Preliminary results suggest that MT quantification may allow improved characterization of the pathologically heterogeneous lesions of multiple sclerosis by providing a measure of demyelination through a sensitivity to myelin proteins. However, MT imaging, as currently most commonly applied, is only a semi-quantitative technique that reflects mixed tissue and experimental parameters in addition to MT. iii In this thesis a novel quantitative MT ResumenLa imagen por transferencia de magnetización (MT) es una técnica de imagen por resonancia magnética nuclear que genera contraste teniendo como base el fenómeno del intercambio de magnetización entre protones de macromoléculas de semisólidos y agua. Esta técnica tiene la propiedad de poder generar imágenes de semisólidos indirectamente, como pueden ser las matrices de proteínas y las membranas celulares, cuya magnetización cae demasiado rápido como para producir imágenes directamente basándose en las propiedades de relajación de los protones del agua interaccionando con los de lípidos. Resultados preliminares sugieren que la cuantificación de MT podría permitir una mejora en la caracterización de las lesiones patológicamente heterogéneas en esclerosis múltiple ofreciendo una medida de la desmielinizacion a través de las proteínas de la mielina. Sin embargo, la imagen MT, en su más amplio rango de aplicación, es solamente una técnica semicuantitativa que refleja una mezcla de tejido y parámetros experimentales junto con MT.En esta tesis, una nueva técnica cuantitativa de imagen (MTsat) se aplica en el cerebro y la espina dorsal cervical con el fin de evaluar si el control de esta limitación puede mejorar la discriminación neuropatológica en sujetos con esclerosis múltiple (MS). Se encontró que MTsat puede discriminar la patología en el cerebro y la espina dorsal cervical que está asociada con los diferentes grados de incapacidad de los pacientes.Además, la señal de regiones del cerebro en donde las técnicas de imagen convencionales no muestran daño de tejido arroja una correlación significativa con las escalas de incapacidad.

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Nothwendigkeit einer feineren mechanischen Zerlegung des Gehirns und der Nerven vor der chemischen, dargestellt aus Beobachtungen

Cited by 31 publications

References 0 publications

The history of myelin

The history of myelin

The sympathetic trunk and its neural pathway to the upper limb: review of the literature

Comparison of magnetization transfer methods for assessing macromolecular bound water in the brain and cervical spinal cord

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