TY - JOUR
T1 - Participation of histaminergic H 1 and noradrenergic α 1 receptors in orexin A-induced wakefulness in rats
AU - Shigemoto, Yuki
AU - Fujii, Yoko
AU - Shinomiya, Kazuaki
AU - Kamei, Chiaki
N1 - Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2004/10/8
Y1 - 2004/10/8
N2 - The participation of histaminergic H 1 and noradrenergic α 1 receptors in orexin A-induced wakefulness was studied by examining the sleep-wakefulness cycle in rats. Intracerebroventricular infusion of orexin A (1 nmol) caused an increase in the wakefulness state, while non-rapid eye movement sleep (NREM sleep) and rapid eye movement sleep (REM sleep) states were decreased. Prazosin (150 nmol) showed no significant antagonistic effect on the orexin A-induced increase in the wakefulness state and decrease in NREM and REM sleep. On the contrary, pyrilamine (150 nmol) was effective in antagonizing orexin A-induced increase in wakefulness and decrease in NREM sleep. When prazosin (150 nmol) and pyrilamine (150 nmol) were simultaneously perfused into the lateral ventricle, an almost complete antagonistic effect was observed with the increase in the wakefulness state and decrease in NREM sleep. Orexin A (1 nmol) caused a significant decrease in the histamine contents of the cortex, hippocampus and hypothalamus, whereas noradrenaline contents were decreased only in the hypothalamus. From these results, we concluded that the arousal effect induced by orexin A occurs through histaminergic H 1 and noradrenergic α 1 receptors, although participation of the H 1 receptor was more important than the α 1 receptor.
AB - The participation of histaminergic H 1 and noradrenergic α 1 receptors in orexin A-induced wakefulness was studied by examining the sleep-wakefulness cycle in rats. Intracerebroventricular infusion of orexin A (1 nmol) caused an increase in the wakefulness state, while non-rapid eye movement sleep (NREM sleep) and rapid eye movement sleep (REM sleep) states were decreased. Prazosin (150 nmol) showed no significant antagonistic effect on the orexin A-induced increase in the wakefulness state and decrease in NREM and REM sleep. On the contrary, pyrilamine (150 nmol) was effective in antagonizing orexin A-induced increase in wakefulness and decrease in NREM sleep. When prazosin (150 nmol) and pyrilamine (150 nmol) were simultaneously perfused into the lateral ventricle, an almost complete antagonistic effect was observed with the increase in the wakefulness state and decrease in NREM sleep. Orexin A (1 nmol) caused a significant decrease in the histamine contents of the cortex, hippocampus and hypothalamus, whereas noradrenaline contents were decreased only in the hypothalamus. From these results, we concluded that the arousal effect induced by orexin A occurs through histaminergic H 1 and noradrenergic α 1 receptors, although participation of the H 1 receptor was more important than the α 1 receptor.
KW - Histamine
KW - Noradrenaline
KW - Orexin A
KW - Rat
KW - Sleep-wakefulness cycle
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U2 - 10.1016/j.brainres.2004.07.031
DO - 10.1016/j.brainres.2004.07.031
M3 - Article
C2 - 15364026
AN - SCOPUS:4444373620
VL - 1023
SP - 121
EP - 125
JO - Molecular Brain Research
JF - Molecular Brain Research
SN - 0006-8993
IS - 1
ER -