BACKGROUND： Nikethamide, a respiratory center stimulant, is widely used in China. However, its effects on the central nervous system and medullary respiratory center remain poorly understood. OBJECTIVE： To investiga...BACKGROUND： Nikethamide, a respiratory center stimulant, is widely used in China. However, its effects on the central nervous system and medullary respiratory center remain poorly understood. OBJECTIVE： To investigate the influence of nikethamide on inspiratory neuron discharge in the medial region of the nucleus retrofacialis in neonatal rats, based on the observations addressing rhythmic respiratory discharge generated by the basic medullary respiratory center and various respiration neuron discharges in brain slices. DESIGN, TIME AND SETTING： A controlled, observational study utilizing in vitro neuroelectrophysiology was performed at the Department of Physiology in Southern Medical University between September and December in 2007. MATERIALS： Nikethamide was purchased from Sigma, USA; BL-420E biological signal collection and manaclement system was provided by Chengdu TME Technology, China.METHODS： Isolated medulla-spinal cord preparations were collected from neonatal Sprague Dawley rats, aged 1-3 days. Tissues were divided to include the medial region of the nucleus retrofacialis, ventral respiratory, and dorsal respiratory groups. Subsequently, modified Kreb＇s solution and 5 μg/mL nikethamide-containing modified Kreb＇s solution were consecutively perfused into the medial region of the nucleus retrofacialis in neonatal rat brain slices. MAIN OUTCOME MEASURES： Hypoglossal nerve root respiratory-related rhythmic discharge activities and inspiratory neuron discharges were recorded with an adsorption electrode and microelectrode. RESULTS Nikethamide resulted in prolonged inspiratory neuron discharge time, shortened respiratory cycle and expiratory time. Nikethamide intervention resulted in enhanced integral amplitude of some inspiratory neurons with no changes in discharge frequency or increased discharge frequency in remaining inspiratory neurons with no changes in integral amplitude. CONCLUSION： Nikethamide excites inspiratory neurons in the basic rhythmic respiration and medullary respiratory center, in addition to increased inspiratory neuron and neural network excitability.展开更多
Experiments were performed on SD rats. The animals were anesthetized with urethane (1. 0 g/kg, i. p. ). The diaphragmatic electric activity and intratracheal pressure were monitored. Morphine (4 mg/kg, i. v. ) caused ...Experiments were performed on SD rats. The animals were anesthetized with urethane (1. 0 g/kg, i. p. ). The diaphragmatic electric activity and intratracheal pressure were monitored. Morphine (4 mg/kg, i. v. ) caused marked respiratory inhibition. The respiratory frequency (RF), integrated diaphragmatic electric activity (IDEA) and diaphragmatic minute activity (DMA) were decreased. The respiratory depression effect of morphine was almost completely eliminated by pretreatment with naloxone injected into the medial areas of the nucleus retrofacialis (mNRF). Bilateral microinjection of morphine (5 μg) into mNRF might result in apnea in all animals. This effect could be fully prevented by injection of naloxone into mNRF in advance. The results suggest that there might be morphine receptors in the mNRF and they might play an important role in the respiratory inhibition induced by systemic administration of morphine.展开更多
BACKGROUND： Morphological data have shown that the most important afferent fibers of papillary body come from hippocampal structure.OBJECTIVE： To observe the changes of evoked potential in hippocampus and the signif...BACKGROUND： Morphological data have shown that the most important afferent fibers of papillary body come from hippocampal structure.OBJECTIVE： To observe the changes of evoked potential in hippocampus and the significance after electrostimulation at medial mamillary nucleus. DESIGN： An observational control experiment.SETTING： Department of Physiology, Shenyang Medical College.MATERIALS ： Twenty-three male or female Wistar rats, 3-4 months old, weighing 270-350 g, were provided by bhe animal room of Shenyang Medical College [the license number was scxk（Liao）2003-0016]. METHODS： The Wistar rats were anaesthetized by intraperintoneal injection of 20% urethane （1 g/kg）, tracheal intubation was also given. The self-made double-pole metal stimulating electrode with the point diameter of 1 mm was inserted into medial mamillary nucleus, the wanted hippocampal guidance spot was found within the rang of the hippocampal region at the same side of tee mamillary body range （CA1-CA4）, inserted with same-core guidance electrode, a sole square-wave stimulation of wave wide 0.2 ms stimulated with electrodes at the applied intensity of 7-9 V, the evoked potential was induced through guidance electrodes, and then input to the ATAC-350 data-processing machine for memory showing wave processing, the memory recorded wave recording graph was separately drawn up by the X-Y recording instrument to observe the latency, time procedure and amplitude of the evoked potential in each hippocampal region of the rats and calculate the percentage of the evoked potential in each hippocampal region. Totally 78 guidance spots in hippocampus were recorded, including 30 positive reaction spots and 48 negative ones. MAIN OUTCOME MEASURES： ① Latency, time procedure and amplitude of the evoked potentials in each hippocampal region of rats; ②percentage of the evoked potentials in each hippocampal region; ③ the wave shapes of the evoked potentials in each hippocampal region from different arrangement in the same positive reaction spot. RESULTS ：① Of the 30 recorded positive reactions, 9 positive spots fused into the stimulated false marks because of the short latency. The analysis of variance showed that the latency had significant difference （P 〈 0.05）, time procedure had highly significant difference （P 〈 0.01 ）, but there was no significant difference in the amplitude （P 〉 0.05） among the hippampal regions.② Among the 30 positive spots, the percentage of evoked potential in the hippocampal regions were 34.5% for CA1, 2.0% for CA2, 24.1% for CA3 and 22.4% for CA4. ③ In different levels of the same positive spot, different changes of the evoked potential wave shapes could be observed, and the most obvious change was that of positive wave amplitude. At different positive spots, evoked potentials of positive phase, negative and the double-phase could be observed. CONCLUSION： There are nerve associations between mamillary body and hippocampus, afferent fibers of mamillary body come from hippocampal CA1 region are a little more.展开更多
本文旨在探讨中枢呼吸兴奋剂尼可刹米对新生大鼠基本节律性呼吸的产生和调节的影响及5-HT2A受体在其中的作用。制作新生大鼠离体延髓脑片标本,含面神经后核内侧区（the medial region of the nucleus retrofacialis,mNRF）并保留舌下神...本文旨在探讨中枢呼吸兴奋剂尼可刹米对新生大鼠基本节律性呼吸的产生和调节的影响及5-HT2A受体在其中的作用。制作新生大鼠离体延髓脑片标本,含面神经后核内侧区（the medial region of the nucleus retrofacialis,mNRF）并保留舌下神经根,灌流改良Kreb＇s液（modified Kreb＇s solution,MKS）,记录舌下神经根呼吸相关节律性放电活动（respiratory-re-lated rhythmic discharge activity,RRDA）,观察不同浓度尼可刹米、5-HT2A受体特异激动剂2,5-二甲氧基-4-碘苯基丙烷[1-（2,5-dimethoxy-4-iodophenyl）-2-aminopropane,DOI]、5-HT2A受体特异拮抗剂酮舍林（ketanserine）以及联合使用尼可刹米和酮舍林对舌下神经根RRDA的影响。结果显示,尼可刹米在0.5-7μg/mL时对延髓脑片RRDA有兴奋作用,在5μg/mL时对吸气时程（inspiratory time,TI）、放电积分幅度（integral amplitude,IA）、呼吸周期（respiratory cycle,RC）等呼吸指标综合效果最显著。DOI明显延长TI、增强IA、缩短RC,对RRDA有兴奋作用。酮舍林明显缩短TI、减弱IA、延长RC,对RRDA有抑制作用。联合使用DOI和酮舍林对RRDA无明显作用。酮舍林可完全阻断尼可刹米对RC的作用,部分阻断尼可刹米对IA的作用,对尼可刹米引起的TI变化无明显影响。结果提示,尼可刹米增强新生大鼠离体延髓脑片舌下神经根RRDA,5-HT2A受体可能是尼可刹米作用途径之一。展开更多
目的探讨5-HT2A受体在延髓面神经后核内侧区(the medial region of nucleus retrofac-ialis,mNRF)对呼吸节律调控的作用。方法仿Suzue方法制作新生大鼠含有舌下神经根及mNRF的离体延髓脑片标本,以吸附电极记录舌下神经根呼吸节律性放电...目的探讨5-HT2A受体在延髓面神经后核内侧区(the medial region of nucleus retrofac-ialis,mNRF)对呼吸节律调控的作用。方法仿Suzue方法制作新生大鼠含有舌下神经根及mNRF的离体延髓脑片标本,以吸附电极记录舌下神经根呼吸节律性放电活动(the respiratory rhythmicdischarge activity,RRDA)并作为呼吸活动的指标,采用全细胞膜片钳记录模式在mNRF同步记录呼吸神经元。分别观察1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane(DOI)、ketanserine对mNRF呼吸起步神经元及RRDA的影响。结果DOI可显著使呼吸周期缩短、放电峰值增加,ketanserine使呼吸周期延长、放电峰值降低;DOI可使Cd2+非敏感性呼吸起步神经元发放幅度、时间、spike的频率显著增加,ketanserine则使其显著减少;voltage steps(电压阶跃)和ramps(斜坡电压法)表明ketanserine可抑制Cd2+非敏感性呼吸起步神经元的短暂性和持久性的钠电流。结论5-HT2A受体兴奋对RRDA、Cd2+非敏感性呼吸起步神经元具有兴奋性作用,是通过调节钠电流而起作用的。展开更多
目的探讨腺苷A1受体在基本呼吸节律产生和调节中的可能作用。方法制作新生大鼠离体延髓脑片标本,主要包含面神经后核内侧区(the medialregion of the nucleus retrofacialis,mNRF),并保留舌下神经根的完整,以改良Kreb's液灌流脑片,...目的探讨腺苷A1受体在基本呼吸节律产生和调节中的可能作用。方法制作新生大鼠离体延髓脑片标本,主要包含面神经后核内侧区(the medialregion of the nucleus retrofacialis,mNRF),并保留舌下神经根的完整,以改良Kreb's液灌流脑片,稳定记录舌下神经根呼吸节律性放电(respiratory rhythmical discharge activity, RRDA)。在灌流液中先分别单独给予腺苷A1受体的特异性拮抗剂8-环戊-1,3-二丙基黄嘌呤(8-cyclopentyl-1,3-dipropylxa nthine, DPCPX)和特异性激动剂R-苯异丙基-腺苷(R-phenylisoprpyl-adeno sine,R-PIA);再分别先后给予R-PIA和R-PIA+ DPCPX,观察RRDA的变化,进一步探讨腺苷A1受体对其的调节作用。结果给予腺苷A1受体拮抗剂DPCPX后,呼气时程和呼吸周期明显缩短,吸气时程和积分幅度未出现显著性变化;给予腺苷A1受体激动剂R-PIA后,吸气时程,积分幅度显著性降低,呼吸周期和呼气时程明显延长,且R-PIA的呼吸抑制作用可部分被DPCPX逆转。结论腺苷A1受体参于了哺乳动物基本呼吸节律的产生和调节中起着重要的作用。展开更多
基金the National Natural Science Foundation of China,No.30570670the Natural Science Foundation of Guangdong Province,No.5004714
文摘BACKGROUND： Nikethamide, a respiratory center stimulant, is widely used in China. However, its effects on the central nervous system and medullary respiratory center remain poorly understood. OBJECTIVE： To investigate the influence of nikethamide on inspiratory neuron discharge in the medial region of the nucleus retrofacialis in neonatal rats, based on the observations addressing rhythmic respiratory discharge generated by the basic medullary respiratory center and various respiration neuron discharges in brain slices. DESIGN, TIME AND SETTING： A controlled, observational study utilizing in vitro neuroelectrophysiology was performed at the Department of Physiology in Southern Medical University between September and December in 2007. MATERIALS： Nikethamide was purchased from Sigma, USA; BL-420E biological signal collection and manaclement system was provided by Chengdu TME Technology, China.METHODS： Isolated medulla-spinal cord preparations were collected from neonatal Sprague Dawley rats, aged 1-3 days. Tissues were divided to include the medial region of the nucleus retrofacialis, ventral respiratory, and dorsal respiratory groups. Subsequently, modified Kreb＇s solution and 5 μg/mL nikethamide-containing modified Kreb＇s solution were consecutively perfused into the medial region of the nucleus retrofacialis in neonatal rat brain slices. MAIN OUTCOME MEASURES： Hypoglossal nerve root respiratory-related rhythmic discharge activities and inspiratory neuron discharges were recorded with an adsorption electrode and microelectrode. RESULTS Nikethamide resulted in prolonged inspiratory neuron discharge time, shortened respiratory cycle and expiratory time. Nikethamide intervention resulted in enhanced integral amplitude of some inspiratory neurons with no changes in discharge frequency or increased discharge frequency in remaining inspiratory neurons with no changes in integral amplitude. CONCLUSION： Nikethamide excites inspiratory neurons in the basic rhythmic respiration and medullary respiratory center, in addition to increased inspiratory neuron and neural network excitability.
文摘Experiments were performed on SD rats. The animals were anesthetized with urethane (1. 0 g/kg, i. p. ). The diaphragmatic electric activity and intratracheal pressure were monitored. Morphine (4 mg/kg, i. v. ) caused marked respiratory inhibition. The respiratory frequency (RF), integrated diaphragmatic electric activity (IDEA) and diaphragmatic minute activity (DMA) were decreased. The respiratory depression effect of morphine was almost completely eliminated by pretreatment with naloxone injected into the medial areas of the nucleus retrofacialis (mNRF). Bilateral microinjection of morphine (5 μg) into mNRF might result in apnea in all animals. This effect could be fully prevented by injection of naloxone into mNRF in advance. The results suggest that there might be morphine receptors in the mNRF and they might play an important role in the respiratory inhibition induced by systemic administration of morphine.
文摘BACKGROUND： Morphological data have shown that the most important afferent fibers of papillary body come from hippocampal structure.OBJECTIVE： To observe the changes of evoked potential in hippocampus and the significance after electrostimulation at medial mamillary nucleus. DESIGN： An observational control experiment.SETTING： Department of Physiology, Shenyang Medical College.MATERIALS ： Twenty-three male or female Wistar rats, 3-4 months old, weighing 270-350 g, were provided by bhe animal room of Shenyang Medical College [the license number was scxk（Liao）2003-0016]. METHODS： The Wistar rats were anaesthetized by intraperintoneal injection of 20% urethane （1 g/kg）, tracheal intubation was also given. The self-made double-pole metal stimulating electrode with the point diameter of 1 mm was inserted into medial mamillary nucleus, the wanted hippocampal guidance spot was found within the rang of the hippocampal region at the same side of tee mamillary body range （CA1-CA4）, inserted with same-core guidance electrode, a sole square-wave stimulation of wave wide 0.2 ms stimulated with electrodes at the applied intensity of 7-9 V, the evoked potential was induced through guidance electrodes, and then input to the ATAC-350 data-processing machine for memory showing wave processing, the memory recorded wave recording graph was separately drawn up by the X-Y recording instrument to observe the latency, time procedure and amplitude of the evoked potential in each hippocampal region of the rats and calculate the percentage of the evoked potential in each hippocampal region. Totally 78 guidance spots in hippocampus were recorded, including 30 positive reaction spots and 48 negative ones. MAIN OUTCOME MEASURES： ① Latency, time procedure and amplitude of the evoked potentials in each hippocampal region of rats; ②percentage of the evoked potentials in each hippocampal region; ③ the wave shapes of the evoked potentials in each hippocampal region from different arrangement in the same positive reaction spot. RESULTS ：① Of the 30 recorded positive reactions, 9 positive spots fused into the stimulated false marks because of the short latency. The analysis of variance showed that the latency had significant difference （P 〈 0.05）, time procedure had highly significant difference （P 〈 0.01 ）, but there was no significant difference in the amplitude （P 〉 0.05） among the hippampal regions.② Among the 30 positive spots, the percentage of evoked potential in the hippocampal regions were 34.5% for CA1, 2.0% for CA2, 24.1% for CA3 and 22.4% for CA4. ③ In different levels of the same positive spot, different changes of the evoked potential wave shapes could be observed, and the most obvious change was that of positive wave amplitude. At different positive spots, evoked potentials of positive phase, negative and the double-phase could be observed. CONCLUSION： There are nerve associations between mamillary body and hippocampus, afferent fibers of mamillary body come from hippocampal CA1 region are a little more.
基金the National Natural Science Foundation of China(No.30570670)the Natural ScienceFoundation of Guangdong Province(No.5004714)
文摘本文旨在探讨中枢呼吸兴奋剂尼可刹米对新生大鼠基本节律性呼吸的产生和调节的影响及5-HT2A受体在其中的作用。制作新生大鼠离体延髓脑片标本,含面神经后核内侧区（the medial region of the nucleus retrofacialis,mNRF）并保留舌下神经根,灌流改良Kreb＇s液（modified Kreb＇s solution,MKS）,记录舌下神经根呼吸相关节律性放电活动（respiratory-re-lated rhythmic discharge activity,RRDA）,观察不同浓度尼可刹米、5-HT2A受体特异激动剂2,5-二甲氧基-4-碘苯基丙烷[1-（2,5-dimethoxy-4-iodophenyl）-2-aminopropane,DOI]、5-HT2A受体特异拮抗剂酮舍林（ketanserine）以及联合使用尼可刹米和酮舍林对舌下神经根RRDA的影响。结果显示,尼可刹米在0.5-7μg/mL时对延髓脑片RRDA有兴奋作用,在5μg/mL时对吸气时程（inspiratory time,TI）、放电积分幅度（integral amplitude,IA）、呼吸周期（respiratory cycle,RC）等呼吸指标综合效果最显著。DOI明显延长TI、增强IA、缩短RC,对RRDA有兴奋作用。酮舍林明显缩短TI、减弱IA、延长RC,对RRDA有抑制作用。联合使用DOI和酮舍林对RRDA无明显作用。酮舍林可完全阻断尼可刹米对RC的作用,部分阻断尼可刹米对IA的作用,对尼可刹米引起的TI变化无明显影响。结果提示,尼可刹米增强新生大鼠离体延髓脑片舌下神经根RRDA,5-HT2A受体可能是尼可刹米作用途径之一。
文摘目的探讨5-HT2A受体在延髓面神经后核内侧区(the medial region of nucleus retrofac-ialis,mNRF)对呼吸节律调控的作用。方法仿Suzue方法制作新生大鼠含有舌下神经根及mNRF的离体延髓脑片标本,以吸附电极记录舌下神经根呼吸节律性放电活动(the respiratory rhythmicdischarge activity,RRDA)并作为呼吸活动的指标,采用全细胞膜片钳记录模式在mNRF同步记录呼吸神经元。分别观察1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane(DOI)、ketanserine对mNRF呼吸起步神经元及RRDA的影响。结果DOI可显著使呼吸周期缩短、放电峰值增加,ketanserine使呼吸周期延长、放电峰值降低;DOI可使Cd2+非敏感性呼吸起步神经元发放幅度、时间、spike的频率显著增加,ketanserine则使其显著减少;voltage steps(电压阶跃)和ramps(斜坡电压法)表明ketanserine可抑制Cd2+非敏感性呼吸起步神经元的短暂性和持久性的钠电流。结论5-HT2A受体兴奋对RRDA、Cd2+非敏感性呼吸起步神经元具有兴奋性作用,是通过调节钠电流而起作用的。
