P133 Modelling REM-NREM activity cycling in infants

Abstract Sleep states in infancy differ from adult sleep states. Due to different cortical and physical manifestations, the REM NREM equivalent infants are often denoted as Active Quiet sleep. Key differences infant REM-NREM cycling include rapid cycling, commencement of state, instead NREM. The physiological mechanisms underlying developmental changes not well understood. We extended an existing, physiologically based model sleep-wake behaviour a REM-on group REM-off group, with mutual inhibition between these providing basis for cycling. pressure driving similar other proposed models motivated by known phenomenon increased following deprivation. found parameter combinations that produce observed early childhood. Through varying parameters governing dynamics drive, is able reproduce both newborn Wake-REM-NREM behaviours older Wake-NREM-REM pattern. Our results suggest clearance plays dominant role determining initial increases wake/NREM controls latency duration. have identified plausible mechanism immature state infants. In line theories sleep’s purpose synaptic remodelling, process which evolves rapidly infancy, we times likely vary along development, triggering switch REM-first NREM-first