A new study with the purpose of identifying the mechanics of cateplexy cataplexy, a rare disorder characterized by the temporary loss of muscle strength in the body, and is often accompanied by the expression of strong emotions such as fear and anger. Cataplexy is also a common symptom of the sleep disorder narcolepsy.
The study, which focused on identifying the mechanics of cataplexy, was conducted by professors John Peever and Christian Burgess, researchers with the U of T’s Department of Cell & Systems Biology. The scientific consensus is that the loss of neurons that produce hypocretin (or orexin), a neurohormone linked to wakefulness and arousal, plays a direct role in the onset of cateplexy in association with narcolepsy. Until recently, the specific mechanisms of cateplectic neurological dysfunction association have been poorly understood.
The U of T study, through observation of cataplexic mice, found that during wakefulness the noradrenaline system in the brain is responsible for maintaining muscle posture through the activation of receptors on skeletal muscle targets. The deficiency of hypocretin decreases this noradrenergic drive, which results in muscle deactivation. If noradrenaline function is restored, symptoms of cateplexy disappear, which provides strong evidence for its role in muscle tone maintenance.
