Topic: rapid-eye-movement sleep

Some 320 million years ago, amniotes began to invade our planet's terrestrial niches. These amniote ancestors gave rise to two lineages that have led to today's mammals (synapsids) and sauropsids (reptiles and birds). Mammals and non-avian reptiles are the only vertebrates with a layered cerebral cortex. To which degree their circadian systems share common mechanisms or have unique adaptions in regulating sleep timing and architecture is unknown. Early circadian studies in reptiles lack conclusive interpretations and technologies have since greatly improved. The bearded dragon is an establishe

Circadian disruption, notably sleep disturbances, serves as an early indicator of Alzheimer’s disease (AD), preceding symptoms like memory loss. The suprachiasmatic nucleus (SCN) governs biological rhythms and receives direct retinal input via melanopsin-expressing retinal ganglion cells (mRGCs) to synchronize with environmental light cycles. The anatomical and functional basis for circadian disruption in AD remains unclear. Here, we explore the relationships between non-visual photoreception, SCN connectome evolution, and sleep regulation in the APP/PS1 mouse model.We measured mRGCs' light-in

When awake, we perceive stimuli from the external world. When asleep, our brain disconnects from the sensory environment. In contrast to these exteroceptive stimuli, little is known about how interoceptive stimuli are processed by the sleeping brain. The vagus nerve is a mixed sensory-motor nerve that interfaces between the autonomic periphery and the brain. We asked whether stimulating specifically vagal sensory afferents modulates sleep. All experiments are based on viral transfection of vGluT2-expressing neurons in the jugular-nodose ganglion of the left vagus nerve, in combination with pol