introduction: previously, we demonstrated that i.p. injection of aqueous extract prepared from aerial parts of drosera spatulata (droseraceae) can induced remarkable analgesia in both phases of formalin test in rats. because, analgesia induced in acute phase of formalin test mainly mediated by activation of central analgesic mechanisms and also paragigantocellularis (pgi) nucleus is part of bra...

in this study the effect of adenosine and caffeine on spontaneous activity of paragigantocellularis (pgi) neurons was investigated. the spontaneous activity of pgi neurons was significantly decreased by microinjection of adenosine (10 nm, 0.5 µl) into pgi nucleus of both control and morphine-dependent rats. the decrease in firing rate of pgi neurons of morphine-dependent rats was greater than t...

introduction: nucleus reticularis paragigantocellularis (pgi) is one of the major components of the rostral ventromedial medulla (rvm), which is involved in nociceptive processing and pain modulation. the aim of this study was to examine the effect of c fiber destruction on responsiveness of nucleus reticularis paragigantocellularis (pgi) to formalin, as a noxious stimulus, in normal and morphi...

Introduction: In this study the effect of Matricaria recutita extract on acute pain in the presence and absence of flumazenil (antagonist of benzodiazepine) and lesioned paragigantocellularis (PGi) nucleus was investigated. Method: Wistar male rats (250±20 g) were used. Animals were grouped randomly into intact, sham and bilateral lesion of PGi nucleus. Intact and lesioned animals, each...

introduction: 17β-estradiol modulates nociception by binding to estrogenic receptors and also by allosteric interaction with other membrane-bound receptors like glutamate and gabaa receptors. beside its autonomic functions, paragigantocellularis lateralis (lpgi) nucleus is also involved in pain modulation. the aim of the current study was to investigate the role of the intracellular estrogenic ...

BACKGROUND Nonsteroidal anti-inflammatory drugs are effective for arthritic pain, but it is unknown whether they also benefit anxiety and depression that frequently coexist with pain. Using the monoarthritis model, the authors evaluated the activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) in structures implicated in both sensorial and emotional pain spheres, and it was veri...

As one of the most important diffused brain modulatory systems, the nucleus locus coeruleus (LC) receives most of its afferents from the nucleus paragigantocellularis (PGi) and plays a major role in the control of drug dependence and some emotional and exciting states. For detailed investigation of the effect of morphine on relationship between these two brain stem nuclei, the activity of the r...

The distribution of reticulocerebellar (RC) neurons was examined by the retrograde transport of horseradish peroxidase (HRP) or wheat germ agglutinin bound to HRP (WGA-HRP) in 7 White Leghorn chickens. A large number of labeled cells were found in the nucleus reticularis pontis caudalis (RP) of the pontomedullary junction and in the nucleus reticularis gigantocellularis (Rgc), parvocellularis (...

Previously we showed that activation of the Nucleus of the Solitary Tract (NTS)-Nucleus Paragigantocellularis (PGi)-Locus coeruleus (LC) pathway, which theoretically culminates with norepinephrine (NE) release in dorsal hippocampus (CA1 region) and basolateral amygdala (BLA) is necessary for the consolidation of object recognition (OR) memory. Here we show that, while the microinjection of the ...