Circadian clocks allow anticipation of daily environmental changes. The suprachiasmatic nucleus (SCN) houses the master clock, but clocks are also widely expressed elsewhere in the body. Although some peripheral clocks have established roles, it is unclear what local brain clocks do. We tested the contribution of one putative local clock in mouse histaminergic neurons in the tuberomamillary nuc...

Pruritus is a common complaint associated with many conditions. It negatively impacts sleep, quality of life, and mortality. Itch is transmitted along both histaminergic and non-histaminergic pathways with a complex interplay between keratinocytes, immune cells and cutaneous neurons. Individuals who present with pruritus should undergo a thorough assessment, especially those over 65 years old, ...

The histaminergic system consists of neurons located in tuberomammillary nucleus of the posterior hypothalamus. It affects many functions of the central nervous system, including regulation of the brainstem cardiovascular center. In this paper, we present current review of the literature concerning the role of the histaminergic system in the cardiovascular regulation in haemorrhagic hypotension...

Long-term potentiation (LTP) in hippocampal CA1 depends on the behavioral state of LTP induction. We hypothesize that histaminergic activity in the septohippocampal system, which is active during walking compared with other behavioral states, is responsible for the behavioral dependence of LTP. Field basal-dendritic EPSPs of CA1 pyramidal cells were recorded in freely behaving rats, and LTP was...

Since one of us, Takehiko Watanabe (TW), elucidated the location and distribution of the histaminergic neuron system in the brain with antibody raised against L-histidine decarboxylase (a histamine-forming enzyme, HDC) as a marker in 1984 and came to Tohoku University School of Medicine in Sendai, we have been collaborating on the functions of this neuron system by using pharmacological agents,...

21 22 Itch of peripheral origin requires information transfer from the spinal cord to the brain for 23 perception. Here, primate spinothalamic tract (STT) neurons from lumbar spinal cord were 24 functionally characterized using in vivo electrophysiology to determine the role of these cells in 25 the transmission of pruriceptive information. 111 STT neurons were identified by antidromic 26 stimu...

The following four possible pathways for itching sensation have been suggested by recent reports. 1) Histaminergic TRPV1-positive pathway: Although histamine-positive nerve fibers cannot strictly be classified as "itch specific" due to their excitation also by pure algogens (making them itch-selective), the existence of a subpopulation of nociceptors responsible for itching is strongly suggeste...

Brain histamine may affect a variety of different behavioral and physiological functions; however, its role in promoting wakefulness has overshadowed its other important functions. Here, we review evidence indicating that brain histamine plays a central role in motivation and emphasize its differential involvement in the appetitive and consummatory phases of motivated behaviors. We discuss the ...

BACKGROUND The brain histaminergic system plays a critical role in maintenance of arousal. Previous studies suggest that histaminergic neurotransmission might be a potential mediator of general anesthetic actions. However, it is not clear whether histaminergic tuberomamillary nucleus (TMN) is necessarily involved in the sedative/hypnotic effects of general anesthetics. METHODS Male Long Evans...