Schwann Cell Suspension Grafts Promote Reconstruction of Transected Postcommissural Fornix in the Adult Rat

Cell suspension grafts from embryonic striatal primordia placed into the adult rat striatum survive well and are able to alleviate a number of behavioral deficits caused by excitotoxic lesions to this structure. However, neither the anatomical connectivity between the graft and host nor the functional recovery elicited by the grafts is completely restored. One way in which the survival and function of embryonic striatal grafts may be enhanced is by the improvement of techniques for the preparation of the cell suspension prior to implantation, an issue that has been addressed only to a limited extent. We have evaluated a number of parameters during the preparation procedure, looking at the effects on cell survival over the first 24 h from preparation using vital dyes and the numbers of surviving neurons in vitro, after 4 days in culture, in addition to graft survival and function in vivo. Factors influencing cell survival include the type of trypsinization procedure and the age of donor tissues used for suspension preparation. The presence of DNase has no effect on cell viability but aids the dissociation of the tissue to form single cells. These results have important implications for the use of embryonic striatal grafts in animal models of Huntington's disease, and in any future clinical application of this research.

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Presence of the myelin-associated glycoprotein correlates with alterations in the periodicity of peripheral myelin.

The Journal of Cell Biology ◽

10.1083/jcb.92.3.877 ◽

1982 ◽

Vol 92 (3) ◽

pp. 877-882 ◽

Cited By ~ 147

Author(s):

B D Trapp ◽

R H Quarles

Keyword(s):

Schwann Cell ◽

Peripheral Nerves ◽

Minor Component ◽

Integral Membrane Protein ◽

Structural Protein ◽

Adult Rat ◽

Pns Myelin ◽

Myelin Associated Glycoprotein ◽

A Minor ◽

Periaxonal Space

The myelin-associated glycoprotein (MAG) is an integral membrane protein (congruent to 100,000 mol wt) which is a minor component of purified peripheral nervus system (PNS) myelin. In the present study, MAG was localized immunocytochemically in 1-micrometer thick Epon sections of 7-d and adult rat peripheral nerves, and its localization was compared to that of the major structural protein (Po) of PNS myelin. To determine more precisely the localization of MAG, immunostained areas in 1 micrometer sections were traced on electron micrographs of identical areas from adjacently cut thin sections.l MAG was localized in periaxonal membranes. Schmidt-Lantermann incisures, paranodal membranes, and the outer mesaxon of PNS myelin sheaths. Compact regions of PNS myelin did not react with MAG antiserum. The results demonstrate MAG's presence in "'semi-compact" Schwann cell or myelin membranes that have a gap of 12-14 nm between extracellular leaflets and a spacing of 5 nm or more between cytoplasmic leaflets. In compact regions of the myelin sheath which do not contain MAG, the cytoplasmic leaflets are "fused" and form the major dense line, whereas the extracellular leaflets are separated by a 2.0 nm gap appearing as paired minor dense lines. Thus, it is proposed that MAG plays a role in maintaining the periaxonal space, Schmidt-Lantermann incisures, paranodal myelin loops, and outer mesaxon by preventing "complete" compaction of Schwann cell and myelin membranes. The presence of MAG in these locations also suggests that MAG may serve a function in regulating myelination in the PNS.

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Neurotrophins and Neuroprotection Improve Axonal Regeneration into Schwann Cell Transplants Placed in Transected Adult Rat Spinal Cord

CNS Regeneration ◽

10.1016/b978-012705070-6/50026-3 ◽

1999 ◽

pp. 631-646 ◽

Cited By ~ 5

Author(s):

Mary Bartlett Bunge ◽

Naomi Kleitman

Keyword(s):

Spinal Cord ◽

Schwann Cell ◽

Axonal Regeneration ◽

Rat Spinal Cord ◽

Adult Rat ◽

Cell Transplants ◽

Adult Rat Spinal Cord

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THE FINE STRUCTURE OF ACOUSTIC GANGLIA IN THE RAT

The Journal of Cell Biology ◽

10.1083/jcb.12.2.329 ◽

1962 ◽

Vol 12 (2) ◽

pp. 329-359 ◽

Cited By ~ 217

Author(s):

Jack Rosenbluth

Keyword(s):

Fine Structure ◽

Schwann Cell ◽

Nerve Cell ◽

Ganglion Cells ◽

Cell Type ◽

High Concentration ◽

Cell Sheets ◽

Adult Rat ◽

Myelin Sheaths ◽

Cytoplasmic Organelles

Nerve cell bodies in the spiral and vestibular ganglia of the adult rat are surrounded by thin (about ten lamellae) myelin sheaths which differ in several respects from typical axonal myelin. In some instances lamellae surrounding perikarya appear as typical major dense lines, and in others as thin Schwann cell sheets in which cytoplasm persists. Discontinuities and irregularities appear in the structure of perikaryal myelin. Lamellae may terminate anywhere within the sheaths; they may bifurcate; they may reverse their direction; or they may merge with each other. The number of lamellae varies from one part of a sheath to another. In addition, the myelin of a single perikaryal sheath may receive contributions from more than one Schwann cell, which overlap and interleave with each other. The ganglion cells are of two types: those which are densely packed with the usual cytoplasmic organelles but have few neurofilaments (granular neurons), and those which exhibit large areas containing few organelles but have a high concentration of neurofilaments (filamented neurons). The latter cell type is ensheathed by myelin which is generally more compact that that surrounding the former. The formation and the physiologic significance of perikaryal myelin are discussed.

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