Generic properties of the oligodendrocyte - Axon network.

The role of oligodendrocytes (OLs) extends beyond saltatory conduction to a modulatory role in neural information processing. Given this exalted role, we take first steps to frame the OL - axon interaction as a network of cells. We find that the OL - axon network has a natural encoding as a bipartite network, allowing us to determine key network properties, estimate the number of OLs or axons in various brain regions and determine the robustness of the network to random removal of cell nodes.

The initiation, design, and establishment of the Desmoid Tumor Research Foundation Patient Registry and Natural History Study.

Desmoid tumors are locally invasive sarcoma, affecting 5-6 individuals out of 1,000,000 per year. The desmoid tumors have high rates of recurrence after resection and can lead to significant deterioration of the quality of life of patients. There is a need for a better understanding of the desmoid tumors' patient experience from first symptoms through diagnosis, disease monitoring, and clinical treatment options.

Distinguishing cell shoving mechanisms.

Motivated by in vitro time-lapse images of ovarian cancer spheroids inducing mesothelial cell clearance, the traditional agent-based model of cell migration, based on simple volume exclusion, was extended to include the possibility that a cell seeking to move into an occupied location may push the resident cell, and any cells neighbouring it, out of the way to occupy that location. In traditional discrete models of motile cells with volume exclusion such a move would be aborted. We introduce a new shoving mechanism which allows cells to choose the direction to shove cells that expends the least amount of shoving effort (to account for the likely resistance of cells to being pushed).

What is the optimal distribution of myelin along a single axon?

The myelin sheath that insulates some axons in the central nervous system allows for faster signal conduction. Previously, axons were thought to be either unmyelinated or fully myelinated. Recent experimental work has discovered a new pattern of myelination (intermittent myelination) along axons in the mouse brain, in which long unmyelinated axon segments are followed by myelinated segments of comparable length.

Evidence for Cooperative Selection of Axons for Myelination by Adjacent Oligodendrocytes in the Optic Nerve.

The cellular mechanisms that regulate the topographic arrangement of myelin internodes along axons remain largely uncharacterized. Recent clonal analysis of oligodendrocyte morphologies in the mouse optic nerve revealed that adjacent oligodendrocytes frequently formed adjacent internodes on one or more axons in common, whereas oligodendrocytes in the optic nerve were never observed to myelinate the same axon more than once. By modelling the process of axonal selection at the single cell level, we demonstrate that internode length and primary process length constrain the capacity of oligodendrocytes to myelinate the same axon more than once.

Is cell migration or proliferation dominant in the formation of linear arrays of oligodendrocytes?

Oligodendrocytes are the myelin-producing cells of the central nervous system that are responsible for electrically insulating axons to speed the propagation of electrical impulses. A striking feature of oligodendrocyte development within white matter is that the cell bodies of many oligodendrocyte progenitor cells become organised into discrete linear arrays of three or more cells before they differentiate into myelin-producing oligodendrocytes. These linear arrays align parallel to the direction of the axons within white matter tracts and are believed to play an important role in the co-ordination of myelination.