Neural circuitry of the suprachiasmatic nucleus and retrochiasmatic area
regulating arousal
Abstract
The suprachiasmatic nucleus (SCN) and retrochiasmatic area (RCA)
innervate the paraventricular nucleus of hypothalamus (PVH) that
projects to the brainstem arousal parabrachial nucleus (PB), which may
form a neural circuit regulating arousal, independent from the circadian
control circuit of arousal. To test the hypothesis, we used DREADDs
(Designer Receptors Exclusively Activated by Designer Drugs) to activate
these regions and examine wakefulness. We found that chemo-stimulation
of the PVH, the SCN, the RCA, and the PVH-PB pathway all significantly
promoted wakefulness, suggesting that a neural circuit consisting of
these nodes regulating arousal.