background: the nucleus raphe magnus (nrm) is involved in thermoregulatory processing. there is a correlation between changes in the firing rates of the cells in the nrm and the application of the peripheral thermal stimulus. introduction: we examined the effect of reversible inactivation and excitation of nrm on mechanisms involved in tail blood flow (tbf) regulation in hypothermia. methods: h...

objective(s): nucleus raphe magnus (nrm) that is involved in the regulation of body temperature contains nitric oxide (no) synthase. considering the effect of no on skin blood flow control, in this study, we assessed its thermoregulatory role within the raphe magnus. materials and methods: to this end, tail blood flow of male wistar rats was measured by laser doppler following the induction of ...

Although the importance of the nucleus raphe magnus in descending inhibitory control of nociception is clear, it is not known whether these effects are equivalent for different types of nociception. Thus, we examined the differential inhibition of behavioral responses evoked by A or C fiber thermonociceptor activation by electrical stimulation of nucleus raphe magnus neurons as well as the invo...

Objective(s): Nucleus Raphe Magnus (NRM) that is involved in the regulation of body temperature contains nitric oxide (NO) synthase. Considering the effect of NO on skin blood flow control, in this study, we assessed its thermoregulatory role within the raphe magnus. Materials and Methods: To this end, tail blood flow of male Wistar rats was measured by laser doppler following the induction of ...

The present studies in the rat employed a combined retrograde transport-immunocytochemical technique to determine the origin in the brainstem of enkephalin (Enk) projections to spinal sympathetic nuclei, including the intermediolateralis nucleus, pars principalis (ILp). We found that Enk projections to the ILp nucleus are found in such serotonergic-containing areas as the raphe obscurus; raphe ...

The distribution and cellular morphology of serotonergic neurons in the brain of two species of monotremes are described. Three clusters of serotonergic neurons were found: a hypothalamic cluster, a cluster in the rostral brainstem and a cluster in the caudal brainstem. Those in the hypothalamus consisted of two groups, the periventricular hypothalamic organ and the infundibular recess, that we...

introduction: the antinociceptive effect of morphine is, in part, mediated through the activation of a descending pathway. one of the major components of this pathway is the nucleus raphe magnus (nrm). our previous study demonstrated the involvement of nrm in the analgesic effect of morphine microinjected into the nucleus cuneiformis (ncf) in a descending manner. the aim of the current study wa...

a b s t r a c tintroduction: the nucleus cuneiformis (ncf) and ventrolateral periaqueductal gray (vlpag), two adjacent areas, mediate the central pain modulation and project to the nucleus raphe magnus (nrm). methods: this study examined whether the antinociceptive effect of morphine microinjected into the ncf is influenced by inactivation of vlpag and nrm in rats. animals were bilaterally micr...

The combined horseradish peroxidase retrograde transport-peroxidase-antiperoxidase immunohistochemical procedure was utilized in the present study to ascertain the sites of origin of serotonin and neurotensin projections to the rodent nucleus raphe magnus. The major serotonin inputs to the raphe magnus arise from the B-8 and B-9 groups of Dahlstrom and Fuxe (Dahlstrom, A., and K. Fuxe (1964) Ac...

Neurons in ventromedial medulla, including the nucleus raphe magnus, project to trigeminal nucleus caudalis and, via the dorsolateral funiculus, to spinal dorsal horn. The terminals of this descending system are in loci containing cells responsive to noxious stimuli. Electrical stimulation of nucleus raphe magnus selectively inhibits spinal dorsal horn neurons that respond to noxious stimuli. T...