Multi-brain-region transcriptional organization linking sleep and affective functions

Sleep and affective behaviors are highly interrelated phenotypes, commonly altered in a variety of neuropsychiatric diseases, including major depressive disorder (MDD). To understand the transcriptomic organization underlying sleep and affective function, we studied a population of (C57BL/6J x 129S1/SvImJ) F2 mice by measuring 283 affective and sleep phenotypes and profiling gene expression across four brain regions, including the frontal cortex, hippocampus, thalamus, and hypothalamus. We identified converging molecular bases for sleep and affective phenotypes at both the single-gene and gene-network levels. Utilizing publicly available transcriptomic datasets collected from sleep-deprived mice and major depressive disorder (MDD) patients, we identified three cortical gene networks altered by sleep/wake changes and depression. The network-level actions of sleep loss and depression were opposite to each other, providing a mechanistic basis for the sleep disruptions commonly observed in depression as well as the reported acute antidepressant effects of sleep deprivation. We highlight one particular network composed of circadian rhythm regulators and neuronal activity-dependent immediate-early genes. The key upstream driver of this network, Arc, may act as a nexus linking sleep and depression. Our data provide mechanistic insights into the role of sleep in affective function and MDD. Integrated network modeling of genotypic, phenotypic, and transcriptomic data collected in a genetically diverse mouse population.