Measurement of hypocretin/orexin content in the mouse brain using an enzyme immunoassay: the effect of circadian time, age and genetic background.
The hypocretins (1 and 2) have emerged as key regulators of sleep and wakefulness. We developed a high-throughput enzyme immunoassay (EIA) to measure total brain hypocretin levels from large numbers of mice. Hypocretin levels were not altered by circadian time or age. However, significant differences in one or both hypocretin peptides were observed between different mouse strains. We studied hypocretin levels in knockout and transgenic mouse models with obesity, circadian gene mutations or monoaminergic defects. Compared to controls, only histamine receptor knockouts had lower hypocretin levels. This was most pronounced in H1 receptor knockouts suggesting the existence of a positive feedback loop between hypocretin and histaminergic neurons.
Lin
L
L
Department of Psychiatry and Behavior Sciences, Center for Narcolepsy and Sleep Disorder, Stanford University, Palo Alto, CA 94304-5742, USA.
Wisor
J
J
Shiba
T
T
Taheri
S
S
Yanai
K
K
Wurts
S
S
Lin
X
X
Vitaterna
M
M
Takahashi
J
J
Lovenberg
T W
TW
Koehl
M
M
Uhl
G
G
Nishino
S
S
Mignot
E
E
D000375:Aging / Q000276:immunology / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000276:immunology / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D002940:Circadian Rhythm / Q000276:immunology / Q000502:physiology; D007124:Immunoenzyme Techniques; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009479:Neuropeptides / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D000068797:Orexins; D011863:Radioimmunoassay
D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins