Assessment of Sleep-wake State-associated Dynamic Changes in Heart Rate Variability in Female Rat: Autonomic System Modelling Approaches for Studying Behavioural Dysregulation

Parasympathetic predominance during NREM sleep was similar to a human having a monophasic pattern, while a higher sympathetic tone during the majority of transitional states in rats, which are polyphasic in nature, indicated risk of dysregulated sympatho-vagal balance with fragmented sleep. Further, the highest parasympathetic activity during the early light phase and the highest sympathetic drive during the dark phase may serve as an adaptive mechanism for survival in nocturnal life.