BACKGROUND： Morphological studies have confirmed that vestibular nuclei accepts serotoninergic projections from nucleus raphe magnus, nucleus raphes pallidus, etc. But it is still unclear whether there is bi-directio...BACKGROUND： Morphological studies have confirmed that vestibular nuclei accepts serotoninergic projections from nucleus raphe magnus, nucleus raphes pallidus, etc. But it is still unclear whether there is bi-directional association between vestibular nuclei and nucleus raphe magnus. OBJECTIVE： To observe the characteristics of projective fibers from vestibular nuclei to nucleus raphe magnus using tetramethyl rhodamine （TMR） in rats, so as to provide more sufficient morphological evidence of neural association from vestibular nuclei. DESIGN： An observational experiment. SETTING： Department of Anatomy （K.K. Leung Brain Research Center）, the Fourth Military Medical University of Chinese PLA. MATERIALS： Eighteen male SD rats of clean degree, weighing 250-280 g, were provided by the Experimental Animal Center of the Fourth Military Medical University of Chinese PLA. METHODS： The experiments were carried out in the laboratory of Department of Anatomy （K.K. Leung Brain Research Center）, the Fourth Military Medical University of Chinese PLA from September 2006 to January 2007. All the rats were anesthetized with intraperitoneal injection of pentobarbital sodium, then according to the coordinates on the rat brain atlas, 0.1 μL TMR （100 g/L） was injected into nucleus raphes magnus via the tip of glass microtubule by means of microinjection. Seven days later, the rats were anesthetized, then perfused and fixed to remove brain, and then frozen coronal brain sections were prepared. The retrogradely labeled neurons in the injected and projected sites were observed under fluorescence microscope. Light filters with evoked wave length of 540-553 nm and emission wave length ≥ 1 580 nm were selected to observe the orange TMR-labeled neurons. All the sections were observed and counted under the fluorescence microscope. MAIN OUTCOME MEASURES： Characteristics and number of retrogradely labeled neurons at different sites of nuclei. RESULTS： Totally 18 SD rats were enrolled, 9 of them were excluded due to the deviation of injected site, and the other 9 were involved in the final analysis of results. The concentrated region of TMR injection was mainly restricted to nucleus raphes magnus, and diffused to the surrounding area to different extents. There were obvious differences in the distributions of the labeled neurons among the subdivisions in vestibular nuclei, as well as the distributions of the labeled neurons at different sites in the same subdivision. The majority of the labeled neurons distributed in the rostral levels of medial vestibular nucleus and the lateral vestibular nucleus, while fewer labeled neurons were observed in superior vestibular nucleus. CONCLUSION： ① There might be bi-directional association between vestibular nucli and nucleus raphe magnus, suggesting that nucleus raphe magnus played a role in the transmission and processing of vestibular information. ② The projection from nucleus raphe magnus to vestibular nucleus has certain distributive characteristics in the region.展开更多
Objective To investigate the role of NRM in the antinociceptive effect of muscle spindle afferents,the influence of NRM lesion on the inhibitory effect of muscle spindle afferents on the nociceptive responses of wide ...Objective To investigate the role of NRM in the antinociceptive effect of muscle spindle afferents,the influence of NRM lesion on the inhibitory effect of muscle spindle afferents on the nociceptive responses of wide dynamic range (WDR) neurons and the effects of the muscle spindle afferents on the NRM neuronal activities were observed. Methods The single units of WDR neurons in the spinal dorsal horn were recorded extracellularly, and the inhibitory effects of activating muscle spindle afferents by intravenous administration of succinylcholine (SCH) on the C fibers evoked responses (C responses) of WDR neurons were tested before and after lesion of NRM.The effects of the muscle spindle afferents activated by administrating SCH on the single NRM neurons were also examined.Results ①It was found that the C responses of WDR neurons were significantly inhibited by intravenously administration of SCH, and the inhibitory effect was reduced after lesion of NRM;②The activities of most of the NRM neurons could be changed significantly by administrating SCH. According to their responses, NRM neurons could be classified into three types:excitatory, inhibitory and non responsive neurons, and the responses were dose dependent. Conclusion These results suggest that the muscle spindle afferents evoked by SCH may activate the NRM neurons, which plays an important role in the antinociception of muscle spindle afferents.展开更多
The main function of Nucleus raphe magnus (NRM) is mostly pain mediation. Our previous study has demonstrated that oxytocin (OXT) regulates antinociception through the central nervous system rather than the peripheral...The main function of Nucleus raphe magnus (NRM) is mostly pain mediation. Our previous study has demonstrated that oxytocin (OXT) regulates antinociception through the central nervous system rather than the peripheral organs, and pain stimulation increases OXT concentration in the NRM. The experiment was designed to investigate OXT in the rat NRM effect on pain modulation. The results showed that 1) pain stimulation increased OXT concentration in NRM perfusion liquid;2) Intra-NRM microinjection of OXT increased the pain threshold in a dose-dependent manner, whereas intra-NRM microinjection of OXT receptor antagonist, desGly-NH2, d(CH2)5[D-Tyr2, Thr-sup-4]OVT decreased the pain threshold;3) NRM pre-treatment with OXT receptor antagonist completely attenuated the pain threshold increase induced by intra-NRM administration of OXT. The data suggested that OXT in NRM was involved in antinociception via OXT receptors.展开更多
(i) The structure and function of the meridian (channel and collateral) described by ancient medical doctors may correspond to the blood circulation, nerve control and neurohumoral modulation of modern medicine. (ii) ...(i) The structure and function of the meridian (channel and collateral) described by ancient medical doctors may correspond to the blood circulation, nerve control and neurohumoral modulation of modern medicine. (ii) The needling, which can injure the tissue, is a noxious stimulation inducing pain. Acupuncture manipulation, such as lifting and thrusting, twisting and twirling, or electroacupuncture (EA) with the sufferable biggest intensity for patients should be a stronger pain stimulation. The needling sensation of soreness, numbness, distension and heaviness is a deep pain. (iii) There is an intrinsic analgesic system in brain, which centers around the periventricular and periaqueductal grey matter, contains endorphins as possible mediators, goes through the descending inhibition system in medulla oblon-gata, and acts on the gating mechanism in spinal cord. Itcould be producing analgesia while the system is activated. (iv) NRM might be a supraspinal center modulating pain, and the R-S neurons could展开更多
基金National Natural Science Foundation of China, No. 30600339
文摘BACKGROUND： Morphological studies have confirmed that vestibular nuclei accepts serotoninergic projections from nucleus raphe magnus, nucleus raphes pallidus, etc. But it is still unclear whether there is bi-directional association between vestibular nuclei and nucleus raphe magnus. OBJECTIVE： To observe the characteristics of projective fibers from vestibular nuclei to nucleus raphe magnus using tetramethyl rhodamine （TMR） in rats, so as to provide more sufficient morphological evidence of neural association from vestibular nuclei. DESIGN： An observational experiment. SETTING： Department of Anatomy （K.K. Leung Brain Research Center）, the Fourth Military Medical University of Chinese PLA. MATERIALS： Eighteen male SD rats of clean degree, weighing 250-280 g, were provided by the Experimental Animal Center of the Fourth Military Medical University of Chinese PLA. METHODS： The experiments were carried out in the laboratory of Department of Anatomy （K.K. Leung Brain Research Center）, the Fourth Military Medical University of Chinese PLA from September 2006 to January 2007. All the rats were anesthetized with intraperitoneal injection of pentobarbital sodium, then according to the coordinates on the rat brain atlas, 0.1 μL TMR （100 g/L） was injected into nucleus raphes magnus via the tip of glass microtubule by means of microinjection. Seven days later, the rats were anesthetized, then perfused and fixed to remove brain, and then frozen coronal brain sections were prepared. The retrogradely labeled neurons in the injected and projected sites were observed under fluorescence microscope. Light filters with evoked wave length of 540-553 nm and emission wave length ≥ 1 580 nm were selected to observe the orange TMR-labeled neurons. All the sections were observed and counted under the fluorescence microscope. MAIN OUTCOME MEASURES： Characteristics and number of retrogradely labeled neurons at different sites of nuclei. RESULTS： Totally 18 SD rats were enrolled, 9 of them were excluded due to the deviation of injected site, and the other 9 were involved in the final analysis of results. The concentrated region of TMR injection was mainly restricted to nucleus raphes magnus, and diffused to the surrounding area to different extents. There were obvious differences in the distributions of the labeled neurons among the subdivisions in vestibular nuclei, as well as the distributions of the labeled neurons at different sites in the same subdivision. The majority of the labeled neurons distributed in the rostral levels of medial vestibular nucleus and the lateral vestibular nucleus, while fewer labeled neurons were observed in superior vestibular nucleus. CONCLUSION： ① There might be bi-directional association between vestibular nucli and nucleus raphe magnus, suggesting that nucleus raphe magnus played a role in the transmission and processing of vestibular information. ② The projection from nucleus raphe magnus to vestibular nucleus has certain distributive characteristics in the region.
基金This research was supported by the National Natural Science Foundation of China(No.390 70 344)
文摘Objective To investigate the role of NRM in the antinociceptive effect of muscle spindle afferents,the influence of NRM lesion on the inhibitory effect of muscle spindle afferents on the nociceptive responses of wide dynamic range (WDR) neurons and the effects of the muscle spindle afferents on the NRM neuronal activities were observed. Methods The single units of WDR neurons in the spinal dorsal horn were recorded extracellularly, and the inhibitory effects of activating muscle spindle afferents by intravenous administration of succinylcholine (SCH) on the C fibers evoked responses (C responses) of WDR neurons were tested before and after lesion of NRM.The effects of the muscle spindle afferents activated by administrating SCH on the single NRM neurons were also examined.Results ①It was found that the C responses of WDR neurons were significantly inhibited by intravenously administration of SCH, and the inhibitory effect was reduced after lesion of NRM;②The activities of most of the NRM neurons could be changed significantly by administrating SCH. According to their responses, NRM neurons could be classified into three types:excitatory, inhibitory and non responsive neurons, and the responses were dose dependent. Conclusion These results suggest that the muscle spindle afferents evoked by SCH may activate the NRM neurons, which plays an important role in the antinociception of muscle spindle afferents.
文摘The main function of Nucleus raphe magnus (NRM) is mostly pain mediation. Our previous study has demonstrated that oxytocin (OXT) regulates antinociception through the central nervous system rather than the peripheral organs, and pain stimulation increases OXT concentration in the NRM. The experiment was designed to investigate OXT in the rat NRM effect on pain modulation. The results showed that 1) pain stimulation increased OXT concentration in NRM perfusion liquid;2) Intra-NRM microinjection of OXT increased the pain threshold in a dose-dependent manner, whereas intra-NRM microinjection of OXT receptor antagonist, desGly-NH2, d(CH2)5[D-Tyr2, Thr-sup-4]OVT decreased the pain threshold;3) NRM pre-treatment with OXT receptor antagonist completely attenuated the pain threshold increase induced by intra-NRM administration of OXT. The data suggested that OXT in NRM was involved in antinociception via OXT receptors.
文摘(i) The structure and function of the meridian (channel and collateral) described by ancient medical doctors may correspond to the blood circulation, nerve control and neurohumoral modulation of modern medicine. (ii) The needling, which can injure the tissue, is a noxious stimulation inducing pain. Acupuncture manipulation, such as lifting and thrusting, twisting and twirling, or electroacupuncture (EA) with the sufferable biggest intensity for patients should be a stronger pain stimulation. The needling sensation of soreness, numbness, distension and heaviness is a deep pain. (iii) There is an intrinsic analgesic system in brain, which centers around the periventricular and periaqueductal grey matter, contains endorphins as possible mediators, goes through the descending inhibition system in medulla oblon-gata, and acts on the gating mechanism in spinal cord. Itcould be producing analgesia while the system is activated. (iv) NRM might be a supraspinal center modulating pain, and the R-S neurons could
