Researchers have identified a signaling pathway that regulates sleep. By studying genetic mutations in mice, they were able to show that an enzyme called histone deacetylase 4 (HDAC4), which is known to suppress gene expression, plays a key role in regulating the amount and depth of sleep. Further experiments revealed that this regulatory signaling in the excitatory neurons of the cortex and hypothalamus regulates sleep quantity and quality, respectively.
