Extracellular histamine level in the frontal cortex is positively correlated with the amount of wakefulness in rats.
Histaminergic neurons have been strongly implicated in the regulation of wakefulness by activating cortical neurons. However, little is known about histamine release in the cortex during sleep-wake stages. In this study, we monitored the extracellular histamine level in the frontal cortex by in vivo microdialysis coupled with electroencephalogram and electromyogram recordings in freely moving rats. The histamine release was 3.8 times higher during wake episodes than during sleep episodes, being positively correlated (r = 0.845) with the time spent in wakefulness. These findings indicate that the histamine release in the cortex is strongly related to the sleep-wake cycle.
Chu
Min
M
Department of Pharmacology, Shanghai Medical College of Fudan University, Shanghai 200032, PR China
Huang
Zhi-Li
ZL
Qu
Wei-Min
WM
Eguchi
Naomi
N
Yao
Ming-Hui
MH
Urade
Yoshihiro
Y
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004563:Electrochemistry / Q000379:methods; D004569:Electroencephalography / Q000379:methods; D004576:Electromyography / Q000379:methods; D005110:Extracellular Space / Q000378:metabolism*; D005625:Frontal Lobe / Q000378:metabolism*; D006632:Histamine / Q000378:metabolism*; D008297:Male; D017551:Microdialysis / Q000379:methods; D051381:Rats; D012894:Sleep Stages / Q000502:physiology; D014851:Wakefulness / Q000502:physiology*
D006632:Histamine