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Redmond SA, Mei F, Eshed-Eisenbach Y, Osso LA, Leshkowitz D, Shen YAA, Kay JN, Aurrand-Lions M, Lyons DA, Peles E, Chan JR. Somatodendritic Expression of JAM2 Inhibits Oligodendrocyte Myelination. Neuron 2016; 91:824-836. [PMID: 27499083 DOI: 10.1016/j.neuron.2016.07.021] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 06/08/2016] [Accepted: 07/01/2016] [Indexed: 02/05/2023]
Abstract
Myelination occurs selectively around neuronal axons to increase the efficiency and velocity of action potentials. While oligodendrocytes are capable of myelinating permissive structures in the absence of molecular cues, structurally permissive neuronal somata and dendrites remain unmyelinated. Utilizing a purified spinal cord neuron-oligodendrocyte myelinating co-culture system, we demonstrate that disruption of dynamic neuron-oligodendrocyte signaling by chemical cross-linking results in aberrant myelination of the somatodendritic compartment of neurons. We hypothesize that an inhibitory somatodendritic cue is necessary to prevent non-axonal myelination. Using next-generation sequencing and candidate profiling, we identify neuronal junction adhesion molecule 2 (JAM2) as an inhibitory myelin-guidance molecule. Taken together, our results demonstrate that the somatodendritic compartment directly inhibits myelination and suggest a model in which broadly indiscriminate myelination is tailored by inhibitory signaling to meet local myelination requirements.
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Affiliation(s)
- Stephanie A Redmond
- Department of Neurology and Program in Neuroscience, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Feng Mei
- Department of Neurology and Program in Neuroscience, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Yael Eshed-Eisenbach
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Lindsay A Osso
- Department of Neurology and Program in Neuroscience, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Dena Leshkowitz
- Bioinformatics Unit, Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Yun-An A Shen
- Department of Neurology and Program in Neuroscience, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Jeremy N Kay
- Departments of Neurobiology and Ophthalmology, Duke University School of Medicine, Durham, NC 27703, USA
| | - Michel Aurrand-Lions
- Centre de Recherche en Cancérologie de Marseille, Inserm, CNRS, Aix-Marseille University, UMR1068, 13284 Marseille, France
| | - David A Lyons
- Centre for Neuroregeneration, Centre for Multiple Sclerosis Research, Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Elior Peles
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel.
| | - Jonah R Chan
- Department of Neurology and Program in Neuroscience, University of California, San Francisco, San Francisco, CA 94143, USA.
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Hámori J, Silakov VL. Myelinated perikarya and dendrites in lateral geniculate nucleus of adult cat following chronic cortical deafferentation. JOURNAL OF NEUROCYTOLOGY 1981; 10:879-88. [PMID: 7310480 DOI: 10.1007/bf01262659] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Chronic (one year) cortical deafferentation resulted in the appearance of myelinated neuronal perikarya and dendritic processes in the lateral geniculate nucleus (LGN) of the cat. Four per cent of all nerve cell bodies, both large and small, were observed to be covered partially or totally by compact myelin sheath. The myelination of the dendrites was confined to the most proximal portion of the processes. A comparison of the fine structural features of the myelinated cell bodies and dendrites with those from intact LGN indicate that both surviving projection neurons and local interneurons may become myelinated. It is suggested that the unorthodox myelination of nerve cell somata and dendrites is caused primarily by the massive deafferentation of the nucleus. This indicates a relationship between synaptic input and the process of myelination of the postsynaptic nerve cells.
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Kemali M, Miralto A. The habenular nuclei of the elasmobranch "Scyllium stellare": myelinated perikarya. THE AMERICAN JOURNAL OF ANATOMY 1979; 155:147-52. [PMID: 463789 DOI: 10.1002/aja.1001550112] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Some habenular cells of the elasmobranch, Scyllium stellare, have a perikaryon completely enveloped by myelin of the compact type. They are found only in the left habenula and not in the right. The myelin sheath accompanies the proximal segment of the process arising from the perikaryon, in a node of Ranvier-like pattern. The identity of these myelinated cells and the functional significance of their myelination are unknown.
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Braak E, Braak H, Strenge H. The fine structure of myelinated nerve cell bodies in the bulbus olfactorius of man. Cell Tissue Res 1977; 182:221-33. [PMID: 902305 DOI: 10.1007/bf00220591] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
In the bulbus olfactorius of man numerous myelinated nerve cell bodies occur in the stratum plexiforme internum and stratum granulosum internum. In many respects they resemble the neighbouring granule cells: small chromatin clumps border on more than half of the circumference of the nucleus, the thin cytoplasmic rim contains abundant polysomes and sometimes pigment complexes with numerous light vacuoles, the cells often show a process which extends up to the stratum glomerulosum, the perikarya are devoid of synaptic contacts whereas the proximal segment of the peripheral processes display rare contacts. The myelin sheath varies in thickness consisting of 2 to 24 lamellae with distances between the major dense lines ranging from 9.3 to 11.3 nm. The myelin sheath may enclose the cell body completely or partially and accompany the proximal segment of the process arising from the perikaryon. On partially enveloped perikarya, the myelin lamellae end in formations like those of the node of Ranvier, though often less regularly. Within the compact myelin sheath all of its lamellae may be distended for a short distance by glial cytoplasm as in the Schmidt-Lanterman incisures of peripheral nerve fibres. Adjacent to the outermost myelin lamella myelinated axons and cell bodies, tentatively identified as oligodendrocytes, as well as granule cells may be closely joined.
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Cooper MH, Beal JA. Myelinated granule cell bodies in the cerebellum of the monkey (Saimiri sciureus). Anat Rec (Hoboken) 1977; 187:249-55. [PMID: 403832 DOI: 10.1002/ar.1091870210] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Electronmicrographs of both the vermis and hemisphere of the cerebellum of the squirrel monkey (Saimiri sciureus) show numerous granule cell bodies partially or completely surrounded by myelin. The myelin is of the compact type and consists of 1 to 13 lamellae. In several cases of partially ensheathed cells the myelin is clearly derived from extensions of myelin sheaths that surround small caliber axons. Either all or only the outer lamellae surrounding the axon contribute to the extensions. In the first instance the myelin buckles at its mesaxon pole and the resulting doubled flap extends for a variable distance along the cell surface.
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Beal JA, Cooper MH. Myelinated nerve cell bodies in the dorsal horn of the monkey (Saimiri sciureus). THE AMERICAN JOURNAL OF ANATOMY 1976; 147:33-48. [PMID: 823813 DOI: 10.1002/aja.1001470104] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
While observing electronmicroscopic preparations of laminae I-III of Rexed ('52), taken from the lumbosacral region of squirrel monkey spinal cord, several small neuronal cell bodies were found which were partially or completely encircled by compact myelin sheaths of varying thickness. Though found in all three laminae, the occurrence of these perikaryal sheaths was less frequent in the "inner zone" of lamina II where there were few myelinated fibers. Perikaryal profiles which were completely surrounded by myelin exhibited meither internal mesaxons nor external tongue processes and the origin of their myelin is obscure. In cases of partially enveloped cells the myelin was often clearly derived from extensions of myelin sheaths surrounding small-diameter axons. These overgrowths of myelin extended away from their axons at a pole near their internal mesaxon and spread out across the surface of neighboring nerve cells. In some cases the extensions were derived from the entire axonal sheath while in others only the external lamellae were included. The external tongue process, when observed, was located at the distal end of the axonal myelin extension. Overgrowths of axonal myelin which were unrelated to neuronal cell bodies were also found but these formations were less extensive.
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Bird M, James DW. Myelin formation in cultures of previously dissociated mouse spinal cord. Cell Tissue Res 1975; 162:93-105. [PMID: 1175220 DOI: 10.1007/bf00223265] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Myelin formation in cultures of previously dissociated spinal cord from foetal mice is described. In addition to the expected pattern of myelination, in which axons are closely wrapped by myelin lamellae, redundant folds of myelin have been found, as have double sheaths surrounding a single axon. Hypotheses concerning the generation of these appearances are discussed. It is suggested that certain intracytoplasmic laminar bodies found in oligodendrocytes in vitro may be of mitochondrial origin.
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