- Author: Hongbiao Chen
- Supervisor: Dr. Michel Besserve
- Date: November 15, 2019
- Place: Neural Information Processing, Graduate Training Center for Neuroscience, University of Tübingen
Abstract
The major function of sleep, system memory consolidation, is believed to achieve by regulating synaptic strength during sleep-state-dependent oscillations. In recent years, experimental evidence shows the up and down effects of sleep oscillations, supporting and against the Synaptic Homeostasis Hypothesis (SHY) that predicts the sleep effects on synaptic strength. Although in 2017 Levenstein proposes a model to explain slow wave effects on the population firing distribution, the mechanisms of single sleep wave and its temporal coordination effect are still unclear. Here I review experiment evidence and computational models of sleep oscillation effects, ranging from single rhythm like NREM SWA effect to multiple nested rhythms like SWA-Spindle, SWA-Ripple, and SWA-Spindle-Ripple coupling effect. In order to understand the mechanism of sleep effect on system memory consolidation, we need a memory experiment task which can collect training data - neural population state activities (including network structure, i.e., involved neuron population and connections), and training algorithm - synaptic plasticity rules (synaptic strength modification rules, like General Oscillation Resonance model). And we also need to find out the sub-function to function links for three abstraction levels - behavior, neural population activities, and synaptic connection weights.
Summary
Sleep rhythms have a critical and active role in system memory consolidation, especially the oscillation temporal coordination such as the coupling of SWA, spindle, and ripples in NREM sleep. The underlying mechanism of sleep oscillation effects on synaptic strength is related to the synaptic modification rules like STDP and the neural firing resonance due to different sleep rhythm regulations.