Glutamate receptor blockade in the rostral ventromedial medulla reduces the force of multisegmental motor responses to supramaximal noxious stimuli

Impaired endocannabinoid signalling in the rostral ventromedial medulla underpins genotype-dependent hyper-responsivity to noxious stimuli.

Pain is both a sensory and an emotional experience, and is subject to modulation by a number of factors including genetic background modulating stress/affect. The Wistar-Kyoto (WKY) rat exhibits a stress-hyper-responsive and depressive-like phenotype and increased sensitivity to noxious stimuli, compared with other rat strains. Here, we show that this genotype-dependent hyperalgesia is associat...

Administration of orexin receptor 1 antagonist into the rostral ventromedial medulla increased swim stress-induced antinociception in rat

Objective(s): Intracerebroventricular injection of orexin-A (hypocretin-1) antagonist has been shown to inhibit stress-induced analgesia. However the locations of central sites that may mediate these effects have not been totally demonstrated. This study was performed to investigate the role of rostral ventromedial medulla (RVM) orexin receptor 1 in stress-induced analgesia (SIA). Materials and...

Dorsal striatum metabotropic glutamate receptor 8 affects nocifensive responses and rostral ventromedial medulla cell activity in neuropathic pain conditions.

The present study investigated the role of metabotropic glutamate receptor subtype 8 (mGluR8) in the dorsal striatum (DS) in modulating thermonociception and rostral ventromedial medulla (RVM) ON and OFF cell activities in conditions of neuropathic pain induced by spared nerve injury (SNI) of the sciatic nerve in rats. The role of DS mGluR8 on mechanical allodynia was also investigated. Intra-D...

Activation of rostral ventromedial medulla neurons by noxious stimulation of cutaneous and deep craniofacial tissues.

The rostral ventromedial medulla (RVM) projects to the medullary and spinal dorsal horns and is a major source of descending modulation of nociceptive transmission. Traditionally, neurons in the RVM are classified functionally as on, off, and neutral cells on the basis of responses to noxious cutaneous stimulation of the tail or hind paw. On cells facilitate nociceptive transmission, off cells ...

Activation of rostral ventromedial medulla neurons by noxious stimulation of cutaneous