Sympathetic nerve activity during sleep, exercise, and mental stress.

This brief review describes recent findings on the differential regulation of sympathetic nerve activity and its role in regulating systemic arterial pressure during rapid eye-movement sleep, non-rapid-eye movement sleep, exercise and freezing behavior (mental stress). We describe the mechanisms underlying the differential regulation of sympathetic outflows and how they act in concert to orchestrate adjustments of cardiovascular function for the whole body, which are optimized to match changes in organ activity in daily activity.