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Capsaicin has been suggested to act not only on thin primary afferents but also on the hypothalamus, but the neurotransmitter(s) of central capsaicin-sensitive neurons are unknown. The present study was conducted to determine whether any central, especially hypothalamic, glutamatergic terminals were sensitive to capsaicin. Capsaicin evoked glutamate release(More)
Although the brain-derived neurotrophic factor (BDNF) gene is activated by the intracellular Ca(2+) signals evoked via Ca(2+) influx into neurons, little is known about how the activation of alternative BDNF gene promoters is controlled by the Ca(2+) signals evoked via N-methyl-d-aspartate receptors (NMDA-R) and L-type voltage-dependent Ca(2+) channels(More)
Serotonin (5-HT) is pruritogenic in humans and suggested to be involved in some pruritic diseases. Our experiments were carried out to determine whether an intradermal injection of 5-HT would elicit itch-associated response in mice and to elucidate the 5-HT receptor subtypes involved in this 5-HT action. 5-HT (14.1-235 nmol site(-1)) injected intradermally(More)
The present study was conducted to clarify whether relief from cancer pain by morphine would suppress tumor growth and metastasis. When given orthotopic inoculation of B16-BL6 melanoma cells into the hind paw, C57BL/6 mice showed moderate and marked hyperalgesia on days 7-10 and from day 14 post-inoculation, respectively. The volume of inoculated hind paw(More)
Rats exposed to a cold environment (4 degrees C) for 30 min every 1 h during the day and at night show a gradual decrease in the nociceptive threshold for pressure stimulation. Such hyperalgesia, referred to as repeated cold stress (RCS)-induced hyperalgesia, is stable for at least 4 h and maintained for 3 days only by exposing to cold overnight; thus, no(More)
The expression of interleukin-1 beta (IL-1 beta) mRNA in the cerebral cortex, hippocampus, striatum, and thalamus of rats was studied after transient forebrain ischemia. IL-1 beta mRNA was not detected in all these regions of sham-operated control rats. IL-1 beta mRNA was induced after transient forebrain ischemia and reached a detectable level in all(More)
Oxaliplatin is a chemotherapy drug and induces peripheral neuropathy which is aggravated by exposure to cold, the mechanism of which is unclear. In the present study, we investigated in mice whether transient receptor potential melastatin 8 (TRPM8), which is activated by cooling temperature, would be involved in cold allodynia induced by oxaliplatin. Mice(More)
Nociceptin has been suggested to be involved in nociceptive processing in the spinal dorsal horn. To investigate whether the biosynthesis of nociceptin is altered in animals with nociceptive hypersensitivity, we examined effects of peripheral inflammation on the expression of prepronociceptin mRNA, especially in the dorsal root ganglion of the rat. Although(More)
We examined the kainic acid-induced changes of mRNA levels of several cytokines such as IL-1 beta, IL-6, TNF alpha and LIF in the rat brain regions using semiquantitative RT-PCR method. IL-1 beta mRNA was markedly increased in the cerebral cortex (CC), thalamus (THL) and hypothalamus (HT) 2 h after the injection of kainic acid in a convulsive dose (12 mg/kg(More)
Vanilloid receptor subtype 1 (VR1), a capsaicin receptor, is expressed in primary sensory neurons and vagal nerves. Heat and protons as well as capsaicin activate VR1 to induce the influx of cations, particularly Ca2+ and Na+ ions. Characteristic effects of capsaicin are the induction of a burning sensation after acute administration and the desensitization(More)