Objective: To study the effects of clinical concentration of sevoflurane on activity of wide dynamic range neurons. Methods: Eight Spraque-Dawley rats(male) were selected. Their spinal cords were exposed and transecte...Objective: To study the effects of clinical concentration of sevoflurane on activity of wide dynamic range neurons. Methods: Eight Spraque-Dawley rats(male) were selected. Their spinal cords were exposed and transected at T 9-10 level. The rate of firings of single neurons in the dorsal horn in response to electrical stimulation of skin was recorded with microelectrodes. The early and late discharges were observed when rats inhaled 0.5%, 1.0%, 1.5%, and 2.0% sevoflurane. Results: Sevoflurane suppressed the early and late discharges at the concentration of 0.5%, 1.0%, 1.5%, and 2.0%. Compared with early discharges, the extent of inhibition of late discharges was wider at the concentration of 1%, 1.5%, and 2.0% of sevoflurane. Conclusion: It is indicated that sevoflurane could suppress the transmission of nociceptive and non-nociceptive stimulation at dorsal horn. The suppression on nociceptive imput is stronger than that on non-nociceptive imput when the concentration of sevoflurane is more than 1%.展开更多
Objective The present study aimed to investigate the electrophysiological properties of wide dynamic range （WDR） neurons in spinal dorsal horn of rats with neuropathic pain induced by lumber 5 （L5） spinal nerve li...Objective The present study aimed to investigate the electrophysiological properties of wide dynamic range （WDR） neurons in spinal dorsal horn of rats with neuropathic pain induced by lumber 5 （L5） spinal nerve ligation （SNL） in a large size of samples.Methods Adult Sprague-Dawley rats were divided into normal and SNL groups.Electrophysiological technique was used to record the characteristics of WDR neurons in the spinal dorsal horn.Results Compared with the WDR neurons in normal rats,the WDR neurons in SNL rats showed an increase in excitability,manifested by an enlargement of the receptive field size,an increase in the proportion of neurons that exhibited spontaneous activities,decreases in the Cresponse threshold and latency,and an increase in the C-response duration.In addition,the numbers of A-and C-fiberevoked discharges were smaller in SNL rats than in normal rats.Conclusion The excitability of spinal WDR neurons increased in rats with neuropathic pain induced by L5 SNL.The increase in excitability of WDR neurons may contribute to the development of neuropathic pain.展开更多
目的:观察三叉神经根慢性压迫损伤对大鼠三叉神经脊束核尾侧亚核(caudal subnucleus of the spinaltrigeminal nucleus,Vc)内广动力范围(wide dynamic range neurons,WDR)神经元自发放电和诱发放电活动的影响。方法:通过慢性压迫损伤三...目的:观察三叉神经根慢性压迫损伤对大鼠三叉神经脊束核尾侧亚核(caudal subnucleus of the spinaltrigeminal nucleus,Vc)内广动力范围(wide dynamic range neurons,WDR)神经元自发放电和诱发放电活动的影响。方法:通过慢性压迫损伤三叉神经根的方法建立三叉神经痛(TN)动物模型,采用在体细胞外记录技术观察空白对照组和TN模型组大鼠Vc内WDR神经元的自发放电和诱发的放电活动。结果:对照组和TN模型组大鼠Vc内WDR神经元自发放电频率分别为0.84±0.15 Hz和3.18±0.59 Hz;口面部感受野分别给予刷、压、夹机械刺激后,对照组大鼠Vc内WDR神经元的诱发放电频率分别为3.27±1.28 Hz、5.62±0.74 Hz和6.76±1.22 Hz,而TN组大鼠诱发放电频率则分别为7.85±1.57 Hz、10.04±0.72 Hz和12.04±1.77 Hz。结论:TN模型组大鼠Vc内WDR神经元的自发放电频率和诱发放电频率均显著高于对照组大鼠,提示三叉神经根慢性压迫损伤可诱导Vc内WDR神经元兴奋性增强。展开更多
In vivo experiments were designed to verify the analgesic effect of Dragon’s Blood and the material basis for this effect. Extracellular microelectrode recordings were used to observe the effects of Dragon’s Blood a...In vivo experiments were designed to verify the analgesic effect of Dragon’s Blood and the material basis for this effect. Extracellular microelectrode recordings were used to observe the effects of Dragon’s Blood and various combinations of the three components (cochinchinenin A, cochinchinenin B, and loureirin B) extracted from Dragon’s Blood on the discharge activities of wide dynamic range (WDR) neurons in spinal dorsal horn (SDH) of intact male Wistar rats evoked by electric stimulation at sciatic nerve. When the Hill's coefficients describing the dose-response relations of drugs were dif-ferent, based on the concept of dose equivalence, the equations of additivity surfaces which can be applied to assess the interaction between three drugs were derived. Adopting the equations and Tal-larida's isobole equations used to assess the interaction between two drugs with dissimilar dose-response relations, the effects produced by various combinations of the three components in modulating the evoked discharge activities of WDR neurons were evaluated. Results showed that Dragon’s Blood and its three components could inhibit the evoked discharge frequencies of WDR neurons in a concentration-dependent way. The Hill's coefficients describing dose-response relations of three components were different. Only the combined effect of cochinchinenin A, cochinchinenin B and loureirin B was similar to that of Dragons Blood. Furthermore, the combined effect was synergistic. This investigation demonstrated that through the synergistic interaction of the three components Dragon’s Blood could interfere with the transmission and processing of pain signals in spinal dorsal horn. All these further proved that the combination of cochinchinenin A, cochinchinenin B, and loureirin B was the material basis for the analgesic effect of Dragon’s Blood.展开更多
文摘Objective: To study the effects of clinical concentration of sevoflurane on activity of wide dynamic range neurons. Methods: Eight Spraque-Dawley rats(male) were selected. Their spinal cords were exposed and transected at T 9-10 level. The rate of firings of single neurons in the dorsal horn in response to electrical stimulation of skin was recorded with microelectrodes. The early and late discharges were observed when rats inhaled 0.5%, 1.0%, 1.5%, and 2.0% sevoflurane. Results: Sevoflurane suppressed the early and late discharges at the concentration of 0.5%, 1.0%, 1.5%, and 2.0%. Compared with early discharges, the extent of inhibition of late discharges was wider at the concentration of 1%, 1.5%, and 2.0% of sevoflurane. Conclusion: It is indicated that sevoflurane could suppress the transmission of nociceptive and non-nociceptive stimulation at dorsal horn. The suppression on nociceptive imput is stronger than that on non-nociceptive imput when the concentration of sevoflurane is more than 1%.
基金supported by the grants from National Natural Science Foundation of China(No. 30600173,81070893)the Key Project of China Ministry of Education(No. 109003)+1 种基金the National Basic Research Development Program(973 Program) of China (No.2007CB512501)Beijing Municipal Commission of Education "Special Grants for Outstanding Ph.D Program Tutors"
文摘Objective The present study aimed to investigate the electrophysiological properties of wide dynamic range （WDR） neurons in spinal dorsal horn of rats with neuropathic pain induced by lumber 5 （L5） spinal nerve ligation （SNL） in a large size of samples.Methods Adult Sprague-Dawley rats were divided into normal and SNL groups.Electrophysiological technique was used to record the characteristics of WDR neurons in the spinal dorsal horn.Results Compared with the WDR neurons in normal rats,the WDR neurons in SNL rats showed an increase in excitability,manifested by an enlargement of the receptive field size,an increase in the proportion of neurons that exhibited spontaneous activities,decreases in the Cresponse threshold and latency,and an increase in the C-response duration.In addition,the numbers of A-and C-fiberevoked discharges were smaller in SNL rats than in normal rats.Conclusion The excitability of spinal WDR neurons increased in rats with neuropathic pain induced by L5 SNL.The increase in excitability of WDR neurons may contribute to the development of neuropathic pain.
基金the Nature Science Foundation of State Ethnic Affairs Commission, China (Grant No. MZY06002)
文摘In vivo experiments were designed to verify the analgesic effect of Dragon’s Blood and the material basis for this effect. Extracellular microelectrode recordings were used to observe the effects of Dragon’s Blood and various combinations of the three components (cochinchinenin A, cochinchinenin B, and loureirin B) extracted from Dragon’s Blood on the discharge activities of wide dynamic range (WDR) neurons in spinal dorsal horn (SDH) of intact male Wistar rats evoked by electric stimulation at sciatic nerve. When the Hill's coefficients describing the dose-response relations of drugs were dif-ferent, based on the concept of dose equivalence, the equations of additivity surfaces which can be applied to assess the interaction between three drugs were derived. Adopting the equations and Tal-larida's isobole equations used to assess the interaction between two drugs with dissimilar dose-response relations, the effects produced by various combinations of the three components in modulating the evoked discharge activities of WDR neurons were evaluated. Results showed that Dragon’s Blood and its three components could inhibit the evoked discharge frequencies of WDR neurons in a concentration-dependent way. The Hill's coefficients describing dose-response relations of three components were different. Only the combined effect of cochinchinenin A, cochinchinenin B and loureirin B was similar to that of Dragons Blood. Furthermore, the combined effect was synergistic. This investigation demonstrated that through the synergistic interaction of the three components Dragon’s Blood could interfere with the transmission and processing of pain signals in spinal dorsal horn. All these further proved that the combination of cochinchinenin A, cochinchinenin B, and loureirin B was the material basis for the analgesic effect of Dragon’s Blood.
