Do enteric neurons make hypocretin?
Hypocretins (orexins) are wake-promoting neuropeptides produced by hypothalamic neurons. These hypocretin-producing cells are lost in people with narcolepsy, possibly due to an autoimmune attack. Prior studies described hypocretin neurons in the enteric nervous system, and these cells could be an additional target of an autoimmune process. We sought to determine whether enteric hypocretin neurons are lost in narcoleptic subjects. Even though we tried several methods (including whole mounts, sectioned tissue, pre-treatment of mice with colchicine, and the use of various primary antisera), we could not identify hypocretin-producing cells in enteric nervous tissue collected from mice or normal human subjects. These results raise doubts about whether enteric neurons produce hypocretin.
Baumann
Christian R
CR
Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Institutes of Medicine, Boston, USA. cbaumann@bidmc.harvard.edu
Clark
Erika L
EL
Pedersen
Nigel P
NP
Hecht
Jonathan L
JL
Scammell
Thomas E
TE
D000818:Animals; D017615:Enteric Nervous System / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009474:Neurons / Q000378:metabolism*; D009479:Neuropeptides / Q000096:biosynthesis*; D018377:Neurotransmitter Agents / Q000096:biosynthesis*; D000068797:Orexins
D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D018377:Neurotransmitter Agents; D000068797:Orexins