Defense Date

2011

Document Type

Thesis

Degree Name

Master of Science

Department

Anatomy & Neurobiology

First Advisor

Jeff Dupree

Abstract

Myelin facilitates the timely, efficient conduction of action potentials along axons. Made by Schwann cells (SCs) in the PNS, myelin is unique in that it is composed of a high percentage of lipids, particularly galactolipids. Sulfatide, one such galactolipid, is made by cerebroside sulfotransferase (CST) and has been shown to play a role in organizing paranodal domains in myelinated axons. However less is known regarding the involvement of sulfatide in the establishment and maintenance of the node, of particular interest as it is responsible for the potentiation of action potentials along the axon. Using immunohistochemical and, to a lesser extent, electron microscopic techniques, we confirm that sulfatide is essential for organization of the paranode. Our data further shows that neuronal nodal clustering and maintenance is paranode-independent, thus not reliant on sulfatide, demonstrating that 1) distinct mechanisms exist for nodal and paranodal organization 2) distinct mechanisms for nodal stability exist in the PNS versus the CNS. Interestingly, maintenance of the SC nodal protein, gliomedin, is sulfatide-dependent, indicating that sulfatide is differentially important for nodal organization depending on the cell of origin. Finally, we observe that despite compromised molecular organization of the nodal and paranodal domains in the absence of sulfatide, the gross structure is preserved, therefore a disconnect exists between molecular and structural organization.

Rights

© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

May 2011

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