Date: Wednesday, October 19, from 3pm to 4pm (refreshments served at 2:45pm!)
Location: In STEM 364 or online using the following Zoom link
Speaker: Afroditi Talidou (University of Ottawa)
Title: Myelination as a modulator of axonal conduction and neural communicationAbstract: The conduction of action potentials along white matter is sensitive to myelin, a lipid-rich material wrapping around axons, formed by glial cells called oligodendrocytes. Myelin notably influences the time it takes for action potentials to traverse toward their postsynaptic targets (known as conduction delay). Conduction delays are critical in brain function due to the dependence of neural communication on spike timing. To better understand neural communication we study the role of myelination on axonal conduction along single axons and networks of neurons. From the point of view of single axons we developed a mathematical model, based on the cable equation, accounting for action potential propagation. We discovered that distinct myelin patterns resulted in variability of axonal conduction delays. Turning to the networks, we developed a model of spiking neurons enhanced with neuron-oligodendrocyte feedback. We examined the relationship between activity-dependent myelination (ADM -- a form of adaptive myelination) and the coordination of neural activity. We found that ADM implements a homeostatic gain control mechanism that enhances neural firing rates through the temporal coordination of action potentials as axon lengths increase.
This is joint work with Jérémie Lefebvre.