Hypocretin/ Orexin Levels in Narcolepsy

 For those who have narcolepsy and have long given up hope of a cure ever being found, the latest research may provide an answer as to why people suffer from narcolepsy, and this knowledge may finally lead to its ultimate cure.

 Narcolepsy appears to be caused by a deficiency of hypocretins otherwise known as orexins. Researchers have found that a significant number of narcoleptic patients have been found to have low to undetectable levels of hypocretin in their cerebro spinal fluid.

Hypocretins or orexins are the names given to a pair of neuropeptide hormones which are synthesized in the hypothalamus and exert their influence on circadian rhythms.It was previously thought that these neuropeptides were involved in stimulating appetite, however, later research has found this not to be the case. Neuropeptides are much smaller molecules but act in a similar manner to neurotransmitters.

 Recent studies have found that narcoleptic patients with low hypocretin/orexin levels have increased obesity, which suggests that low levels of these neuropeptides play a role in increased food intake.

A study done in 1999 by Masashi Yanagisawa et al, University of Texas Southwestern Medical Center found that mice which had been genetically manipulated had symptoms similar to narcolepsy. Another group of researchers in California found that dogs with narcolepsy had a faulty receptor for hypocretin.When further studies were done on human subjects who had narcolepsy and catalepsy, the hypocretin levels in their spinal fluid was found to be very low.

Exactly why the hypocretin levels are low in some members  of the population with narcolepsy is unclear.Is it a genetic problem, brain damage, toxin exposure, faulty diet, none of these questions are answered.

However, the fact that low levels of hypocretins have been found in narcoleptic subjects, points the way to a possible cure of the problem with hypocretin supplementation. Consideration has also been given to replacing hypocretin producing cells in the central nervous system.

Unfortunately topping up hypocretin levels with hypocretin based drugs , or replacing cells without understanding why hypocretin levels are particularly low in these subjects fails to investigate causation, just dealing with the results appears to be the usual modus operandi of medicine. However, for a patient condemned to a life coping with the consequences of such a debilitating disease as  narcolepsy, any drug produced which could increase alertness and allow them to lead a normal life would be a bonus.

Read more:Eating Disorders often Accompany Narcolepsy