Boundary conditions for synaptic homeodynamics during the sleep-wake cycle

Abstract

AbstractUnderstanding synaptic dynamics during the sleep-wake cycle is crucial yet controversial. While some studies report synaptic depression during non-rapid eye movement (NREM) sleep, others observe synaptic potentiation. To find boundary conditions between these contradictory observations, we focused on learning rules and firing patterns that contribute to the synaptic dynamics. Using computational models, we found that under Hebbian and spike-timing dependent plasticity (STDP), wake-like firing patterns decrease synaptic weights, while sleep-like patterns strengthen synaptic weights. Conversely, under Anti-Hebbian and Anti-STDP, synaptic depression during NREM sleep was observed, aligning with the conventional synaptic homeostasis hypothesis. Moreover, synaptic changes depended on firing rate differences between NREM sleep and wakefulness. We provide a unified framework that could explain synaptic homeodynamics under the sleep-wake cycle.