Polyamines (putrescine, spermidine and spermine) are important endogenous regulators of ion channels, such as vanilloid (TRPV1), glutamatergic (NMDA or AMPA/kainate) and acid-sensitive (ASIC) receptors. In the present study, we have investigated the possible nociceptive effect induced by polyamines and the mechanisms involved in this nociception in vivo. The subcutaneous (s.c.) injection of cap...

Highly branched class IV multidendritic sensory neurons of the Drosophila larva function as polymodal nociceptors that are necessary for behavioral responses to noxious heat (>39 degrees C) or noxious mechanical (>30 mN) stimuli. However, the molecular mechanisms that allow these cells to detect both heat and force are unknown. Here, we report that the pickpocket (ppk) gene, which encodes a Deg...

BACKGROUND Dezocine is a powerful analgesic that can be less addictive than morphine, yet how the two drugs interact in vivo is poorly understood. Here we administered dezocine alone or in combination with morphine to different acute nociception paradigms to explore the interactions of the 2 drugs upon co-administration. OBJECTIVE To evaluate how dezocine interacts with morphine in different ...

The effects of CB1 receptor agonist HU-210 and cannabinoid CB1 receptor antagonist SR 141716A on nociception of male Wistar rats with a model of depression (bilateral olfactory bulbectomy, OBX) were studied. HU-210 (5 μg) and SR 141716A (3 μg) were acutely microinjected i.c.v. on the developed depression background. Nociception was examined as applied mechanical pressure on the left hind paw of...

It is generally acknowledged that humans display highly variable sensitivity to pain, including variable responses to identical injuries or pathologies. The possible contribution of genetic factors has, however, been largely overlooked. An emerging rodent literature documents the importance of genotype in mediating basal nociceptive sensitivity, in establishing a predisposition to neuropathic p...

The role of dopamine as a possible central inhibitory mediator of pain processes has been demonstrated. The administration of L-Dopa diminishes pain perception in humans as well as the response to nociceptive stimuli in animals. Also, the intracerebral microinjection of dopamine in inflammatory and neuropathic pain models (formalin test and deafferentation, respectively) reduces nociceptive res...