University of Otago Ōtākou Whakaihu Waka-led research has found stress-controlling brain cells switch on and off in a steady rhythm about once every hour—even when nothing stressful is happening.

Senior author Associate Professor Karl Iremonger, of Otago’s Department of Physiology and Center for Neuroendocrinology, says these rhythms shape activity patterns and alertness.

These bursts of brain cell activity seem to act like a natural ‘wake-up’ signal, and often lead to a rise in stress hormones, or cortisol.