How axons are selectively ensheathed by specific amounts of myelin is a fundamental and unsolved problem in neurobiology. Myelin, produced by oligodendrocytes in the central nervous system of vertebrate animals, enhances axonal conduction of electrical impulses and provides axons with metabolic support. Evidence accumulated over the past several years indicates that myelination can adapt to neuronal activity, and that adaptive myelination is essential for learning and new skill development. The next important step is to identify the molecular functions that mediate communication between neurons and oligodendrocytes to facilitate adaptive myelination. Building on our own evidence that activity-evoked axonal vesicular secretion promotes myelin sheath growth, we hypothesize that proteins that function in synaptic communication between neurons also mediate synaptic-like signaling between axons and oligodendrocytes. We will test this hypothesis using zebrafish and mice, building on our expertise in zebrafish genome modification, mouse in utero electroporation and imaging of oligodendrocyte lineage cells in both species. Our experimental plan has two parts. First, we will investigate the expression and subcellular localization of synaptic proteins identified by RNA-seq profiling of oligodendrocyte lineage cell transcripts. Second, we will initiate loss-of-function studies to learn if synaptic proteins promote myelin sheath growth in vivo. This project has the potential to reveal important new mechanistic insights to adaptive myelination and the results will create a foundation for future, detailed investigations of axon- oligodendrocyte communication.

Public Health Relevance

In vertebrate animals, many neuronal axons are ensheathed by myelin, a specialized membrane made by glial cells called oligodendrocytes. Axonal myelination can adapt to experience to enhance learning and skill development, but the molecular mechanisms that mediate adaptive myelination are not known. This project aims to identify molecules that convey signals between axons and oligodendrocytes to regulate myelination in response to brain activity.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Exploratory/Developmental Grants (R21)
Project #
1R21NS110213-01
Application #
9682208
Study Section
Cellular and Molecular Biology of Glia Study Section (CMBG)
Program Officer
Morris, Jill A
Project Start
2018-09-01
Project End
2020-08-31
Budget Start
2018-09-01
Budget End
2019-08-31
Support Year
1
Fiscal Year
2018
Total Cost
Indirect Cost
Name
University of Colorado Denver
Department
Pediatrics
Type
Schools of Medicine
DUNS #
041096314
City
Aurora
State
CO
Country
United States
Zip Code
80045