Support our work
Decorative header background

Opiates increase the number of hypocretin-producing cells in human and mouse brain and reverse cataplexy in a mouse model of narcolepsy.

Research group Swaab
Publication year 2018
Published in Science Translational Medicine
Authors L. Shan, D.F. Swaab, T.C. Thannickal, J. John, M.F. Wu, L. Ramanathan, R. McGregor, K.T. Chew, M. Cornford, A. Yamanaka, A. Inutsuka, Rolf Fronczek, G.J. Lammers, P.F. Worley, J.M. Siegel,
The order of authors may deviate from the original publication due to temporary technical issues.

The changes in brain function that perpetuate opiate addiction are unclear. In our studies of human narcolepsy, a disease caused by loss of immunohistochemically detected hypocretin (orexin) neurons, we encountered a control brain (from an apparently neurologically normal individual) with 50% more hypocretin neurons than other control human brains that we had studied. We discovered that this individual was a heroin addict. Studying five postmortem
brains from heroin addicts, we report that the brain tissue had, on average, 54% more immunohistochemically detected neurons producing hypocretin than did control brains from neurologically normal subjects. Similar increases in hypocretin-producing cells could be induced in wild-type mice by long-term (but not short-term) administration of morphine. The increased number of detected hypocretin neurons was not due to neurogenesis and outlasted morphine administration by several weeks. The number of neurons containing melanin-concentrating hormone, which are in the same hypothalamic region as hypocretin-producing cells, did not change in response to morphine administration. Morphine administration restored the population of detected hypocretin cells to normal numbers in transgenic mice in which these neurons had been partially depleted. Morphine administration also decreased cataplexy in mice made narcoleptic by the depletion of hypocretin neurons. These findings suggest that opiate agonists may have a role in the treatment of narcolepsy, a disorder caused by hypocretin neuron loss, and that increased numbers of hypocretin-producing cells may play a role in maintaining opiate addiction.

Support our work!

The Friends Foundation facilitates groundbreaking brain research. You can help us with that.

Support our work