Modulation mode of amygdala morphology and cognitive function under acute sleep deprivation in healthy male

The amygdala plays a crucial role in various behavioral functions and psychiatric conditions, with its morphology showing alterations in sleep disorders. While the impact of chronic sleep disorders on amygdala morphology has been studied, the effects of acute sleep deprivation (ASD) remain largely unexplored. The present study aimed to investigate the modulation between amygdala sub-region volumes and spatial working memory (SWM) performance under ASD conditions. Twenty-eight healthy male participants underwent MRI scanning and performed SWM tasks before and after 24 h of ASD. Amygdala sub-region volumes were segmented into nine sub-regions, and Granger causality analysis was employed to examine the relationship between amygdala morphology and SWM performance. Results revealed significant decreases in SWM accuracy and increases in reaction time following ASD. Localized changes in amygdala sub-regions were observed, with increased left cortico-amygdaloid transition area (CAT) volume and decreased right paralaminar nucleus (PL) volume. Granger causality analysis uncovered a bidirectional modulation between centromedial and cortical-like nuclei, and a progressive involvement of amygdala sub-regions in modulating SWM performance as task difficulty increased. These findings demonstrate a complex interplay between sleep, amygdala morphology, and cognitive function, suggesting that the amygdala plays a crucial role in modulating cognitive performance under ASD conditions. The differential involvement of amygdala sub-regions across varying cognitive loads indicates a flexible and adaptive system attempting to maintain performance in the face of sleep loss.