Narcolepsy tagged posts

External stimulus causing excitement such as laughter by a joke augments the amygdala activity. In narcolepsy patient (left) lacking orexin neurons, activities of the amygdala become excessive, causing cataplexy. In healthy person (right), orexin neurons augment the activities of serotonin neurons in the dorsal raphe nucleus, which reduce activities of the amygdala due to increased release of serotonin in the amygdala, which in turn inhibits cataplexy. Credit: Kanazawa University

The brain is equipped with sleep mechanism and wakefulness mechanism, which are regulated to be on or off in an adequate manner. It is orexin*1 that is important in regulating this switch...

Orexin image provided by researchers. Credit: Image courtesy of University of Tsukuba

A potent compound that promotes wakefulness and remedies the sleep disorder narcolepsy in model animals has been developed by a team of scientists. The compound works to mimic the action of a wake-promoting substance in our brain called “orexin.”.

Orexin, discovered in 1998 by Yanagisawa, is a neuropeptide that plays a central role in maintaining wakefulness. Its deficiency causes narcolepsy, in which patients experience excessive daytime sleepiness, often falling asleep uncontrollably. Patients also suffer from symptoms such as cataplexy (sudden loss of muscle tone triggered by emotion), vivid hallucinations when going into or out of sleep, and sleep paralysis...