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The hypothesis that histaminergic neurons are involved in brain arousal is supported by many studies. However, the effects of the selective long-term abolition of histaminergic neurons on the sleep-wake cycle, indispensable in determining their functions, remain unknown. We have compared brain histamine(HA)-immunoreactivity and the cortical-EEG and(More)
To determine the respective role played by orexin/hypocretin and histamine (HA) neurons in maintaining wakefulness (W), we characterized the behavioral and sleep-wake phenotypes of orexin (Ox) knock-out (-/-) mice and compared them with those of histidine-decarboxylase (HDC, HA-synthesizing enzyme)-/- mice. While both mouse strains displayed sleep(More)
BACKGROUND It is a controversial issue whether pancreas divisum (PD) induces pancreatitis. All previous studies have investigated this issue based on endoscopic procedures, which inevitably involve a selection bias. OBJECTIVES To determine the unbiased prevalence rate of PD in a community population and to investigate the effect of PD on idiopathic(More)
Tourette syndrome (TS) is characterized by tics, sensorimotor gating deficiencies, and abnormalities of cortico-basal ganglia circuits. A mutation in histidine decarboxylase (Hdc), the key enzyme for the biosynthesis of histamine (HA), has been implicated as a rare genetic cause. Hdc knockout mice exhibited potentiated tic-like stereotypies, recapitulating(More)
BACKGROUND The present study observed effects of the histamine H(4) receptor on chronic allergic contact dermatitis induced by repeated challenge in mice. METHODS Acute contact dermatitis was induced by single epicutaneous challenge of 2,4,6-trinitro-1-chlorobenzene (TNCB) to the ear. Chronic allergic contact dermatitis was developed by repeated(More)
The hypocretins (Hcrts) (also called orexins) are two neuropeptides expressed in the lateral hypothalamus that play a crucial role in the stability of wakefulness. Previously, our laboratory demonstrated that in vivo photostimulation of Hcrt neurons genetically targeted with ChR2, a light-activated cation channel, was sufficient to increase the probability(More)
Histidine decarboxylase (HDC) synthesizes histamine from histidine in mammals. To evaluate the role of histamine, we generated HDC-deficient mice using a gene targeting method. The mice showed a histamine deficiency and lacked histamine-synthesizing activity from histidine. These HDC-deficient mice are viable and fertile but exhibit a decrease in the(More)
Brain histaminergic neurons play a prominent role in arousal and maintenance of wakefulness (W). H(3)-receptors control the activity of histaminergic neurons through presynaptic autoinhibition. The role of H(3)-receptor antagonists/inverse agonists (H(3)R-antagonists) in the potential therapy of vigilance deficiency and sleep-wake disorders were studied by(More)
Recent clinical studies reported the drug interaction between proton-pump inhibitors (PPI) and clopidogrel, which remains controversial. The aim of this study was to determine whether the concurrent use of PPI with clopidogrel or ticlopidine is associated with increased risk for adverse cardiovascular outcomes in patients with coronary artery disease (CAD)(More)
To clarify functional roles of histamine in the circadian clock system, circadian rhythms of behavior and clock gene expression in the brain were examined in the mouse lacking histidine decarboxylase (HDC-/- mouse). Wheel-running and spontaneous locomotion were recorded under light-dark cycle (LD) and constant darkness (DD). mPer1, mPer2 and mBMAL1 mRNA(More)