Mostly Biomathematics Lunchtime Seminar

---

Spontaneous local sleep-wake transition induced by synaptic weight dynamics

Speaker: Guanhua Sun, PhD Candidate, Department of Mathematics, University of Michigan

Location: Warren Weaver Hall 1314

Date: Tuesday, May 9, 2023, 12:45 p.m.

Synopsis:

During the later stages of non-rapid eye movement (NREM) sleep, also known as deep sleep, the brain exhibits a mysterious rhythm called slow-wave activity (SWA). SWA is a 0.5 to 4 Hz neuronal oscillation that is synchronized across almost the entire cortex and is thought to help facilitate important brain functions. But in recent years, researchers have also observed SWA in local brain areas during the day. The phenomenon is known as "local sleep" and little is known about its cause and regulatory mechanism. 

In my upcoming talk, I will present a computational model consisting of spiking neurons and calcium-based plasticity that mimics a local cortex network. Surprisingly, the model can exhibit both sleep and wake behavior and transition spontaneously between them, without external regulation or changing the electrophysiology of neurons. Further analysis will show that these transitions are triggered by the synaptic weight change, both in magnitude and distribution within the network. I will discuss the model’s implications toward the understanding of local sleep.