兔孤束核腹外侧区微量注射谷氨酸钠及甘氨酸对膈神经放电的影响

实验在４０只麻醉、制动、断双侧颈迷走神经和人工通气的家兔上进行。在孤束核腹外侧区微量注射神经元胞体兴奋剂谷氨酸钠和抑制剂甘氨酸,探讨膈神经放电的变化。结果：微量注射谷氨酸钠,可使膈神经放电脉冲数明显增加,吸气时程延长,呼气时程缩短,呼吸频率变化不明显;微量注射甘氨酸,则膈神经放电脉冲数显著减少,甚至停止,吸气时程缩短,呼气时程不规则延长,呼吸频率降低。上述结果提示：孤束核腹外侧区对呼吸节律的形成具     

燕雀上纹状体腹侧尾核对发声和呼吸的调制效应及其纤维联系

在乌拉坦麻醉的鸣禽燕雀（Ｆｒｉｎｇｉｌｌａｍｏｎｔｉｆｒｉｎｇｉｌｌａ）上,观察电刺激上纹状体腹侧尾核（ＨＶｃ）对发声和呼吸的影响,随后在ＨＶｃ内注入ＣＢ－ＨＲＰ溶液,研究ＨＶｃ的中枢联系。结果如下：（１）电刺激ＨＶｃ的不同区域都引起鸣叫反应。（２）长串电脉冲刺激ＨＶｃ,产生明显的呼吸易化效应,表现为增频增幅的呼吸。（３）吸气期用短串电脉冲刺激ＨＶｃ,产生吸气切断效应;刺激落位于呼气相,可使该呼气时程明显延长,以配合鸣叫,然后转变为增频增幅的呼吸。（４）ＣＢＨＲＰ法表明,ＨＶｃ投射到古纹状体粗核和嗅叶Ｘ区,ＨＶｃ接受新纹状体前部大细胞核内侧部、新纹状体中部界面核、端脑听核－Ｌ区、丘脑葡萄形核及脑桥蓝斑核的传入投射。提示ＨＶｃ除控制发声外,尚参与呼吸易化的调制。ＨＶｃ对发声及呼吸的特异性影响,可能在鸣叫与呼吸的协调机制中起重要作用。     

兔杏仁中央核中心区微量注射吗啡,纳洛酮对膈神经放电的影响

实验在24只家兔身上观察了微量注射吗啡、纳洛酮于杏仁中央核(ACE)中心区对膈神经放电的影响,同时监测动脉血压,主要结果如下:(1)ACE中心区微量注射m吗啡,不同动物出现两种不同的呼吸效应,一为吸气时程延长,膈神经放电积分幅值升高;二为膈神经放电积分幅值下降,呼吸时程无明显变化。(2)ACE中心区微量注射纳洛酮,呼吸频率增加,积分幅值升高,吸气时程缩短。(3)预先注射纳洛酮,可阻断吗啡在ACE中心区的吸气延长效应,而对其它的呼吸指标不产生影响。提示:ACE神经元上可能存在有内源性吗啡受体,内源性吗啡通过其受体可对呼吸产生影响。     

前包钦格复合体区微量注射氨基酸类药物的呼吸效应

实验选用成年大鼠 ,腹腔注射戊巴比妥钠麻醉 ,以膈神经放电为指标 ,分别观察了在前包钦格复合体(pre B¨otzingercomplex ,pre B¨ot复合体 )内微量注射兴奋性氨基酸 (红藻氨酸 ,KA ;L 谷氨酸 ,Glu)和抑制性氨基酸(甘氨酸 ,Gly ;γ 氨基丁酸 ,GABA)对呼吸活动的影响。在pre B¨ot复合体内注射KA后 ,所有动物首先出现呼吸兴奋效应 ,表现为吸气时程 (TI)延长 ,呼气时程 (TE)缩短 ,呼吸频率 (RF)增快 ;随后出现呼吸抑制效应 ,表现为呼吸停止于呼气状态。Pre B¨ot复合体内注射Glu ,引起动物TE 缩短 ,注射Gly或GABA均引起动物TI 缩短。这些结果表明 ,成年大鼠pre B¨ot复合体参与节律性呼吸活动的产生和调控 ,它可能是启动和维持吸气过程的中枢结构。     

大鼠延髓旁巨细胞外侧核微量注射利多卡因对呼吸和血压的影响

用在体的方法研究了大鼠旁巨细胞外侧核在呼吸和血压调控中的作用,在旁巨细胞外侧核内微量注射２００ｎｌ的利多卡因可使７／９大鼠的呼气时程（Ｔｅ）缩短（Ｐ＜０．０５）,呼吸频率增加（Ｐ＜０．０５）,隔肌肌电积分幅度（Ａ）降低（Ｐ＜０．０５）;７／９大鼠的动脉血压下降（Ｐ＜０．０５）。结果表明,大鼠的旁巨细胞外侧核参与呼吸活动和血压活动的调控。     

面神经核腹内侧区微量注射三种递质的呼吸效应

实验用兔,在乌拉坦静脉麻醉、切断双侧颈迷走神经、自主呼吸条件下进行,以膈神经放电作呼吸指标。观察了面神经核腹内侧区(VMNF)微量注射三种递质对呼吸节律的影响。结果如下:(1)VMNF 区微量注射肾上腺素呼吸频率增加,膈神经吸气性放电的递增速度加快,积分幅度升高,VMNF 区微量注射妥拉苏林,呼吸频率下降且妥拉苏林可阻断肾上腺素的呼吸效应。(2)VMNF 区微量注射γ-氨基丁酸、甘氨酸导致呼吸频率下降,吸气时程、呼气时程延长。提示肾上腺素、γ-氨基丁酸、甘氨酸可能作为递质作用于 VMNF 区的神经元而发挥呼吸调节作用。     

电及谷氨酸钠刺激兔杏仁中央核中心区对呼吸的调制效应

本实验在50只氨基甲酸乙酯麻醉的健康家兔上观察了电、化学刺激杏仁中央核(ACE)中心区对呼吸的影响,以膈神经放电做为呼吸观测指标,结果如下:1.长串电脉冲刺激ACE中心区,产生明显的呼吸易化效应,表现为吸气时程延长或增频增幅。2.短串电脉冲刺激ACE中心区,落位于吸气相中期,可使该吸气相明显延长;落位于呼气相中期,可使该呼气相提前结束向吸气相转换。3.微量注射胞体兴奋剂谷氨酸钠(MSG),产生与电刺激该区相似的呼吸易化效应。4.上述电、化学刺激的区域对照和盐水对照实验,均未出现有意义的呼吸改变。提示:ACE中心区细胞体的兴奋,对呼吸具有特异性影响,它参与了呼吸调节,可能在易化基本呼吸节律发生机制中起重要作用。     

氧自由基的损伤程度决定制动应激对损伤心脏心室电稳定性的影响

本文比较了在制动应激过程中正常及阿霉素心肌损伤大鼠心室电稳定性（ＶＥＳ）的变化间的差异。应激各时程,ｉｖｇｔｔ乌头碱（０．８μｇ／ｍｉｎ）,心肌损伤大鼠出现心律失常的潜伏期均较正常鼠明显缩短,说明其较正常大鼠更易发生心律失常。正常大鼠随应激时程的延长,ＶＥＳ变化表现为先降后升,而阿霉素大鼠制动２ｈ,室速、室颤潜伏期及其持续时间虽也显著缩短,但制动８ｈ心律失常发生却无明显改变,提示持续制动应激对正常     

电和L—谷氨酸钠刺激兔中缝隐核对膈神经放电的影响

实验在45只麻醉、自主呼吸、断双侧颈迷走神经的家兔上进行。电刺激或微量注射L-谷氨酸钠于中缝隐核(Nucleus raphe obscurus,NRO),观察到:(1)长串电脉冲刺激NRO(50—200μA,波宽0.3ms,100Hz,4—6s),出现膈神经放电被抑制的反应,被抑制的程度与刺激强度、刺激频率间存在相关性。(2)吸气期用短串电脉冲(100—200μA,波宽0.3ms,50—100Hz,5—20个脉冲)刺激NRO,可提前终止膈神经放电,产生吸气切断效应。吸气切断时间具有刺激落位和刺激强度依赖性。(3)NRO内微量注射细胞体兴奋剂谷氨酸钠(1mol/L,1μl),注药期间出现膈神经放电抑制,注药后为吸气时程(Ti)缩短和呼气时程(Te)延长。     

刺激黄雀新纹状体前部大细胞核外侧部对发声和呼吸的影响

实验材料为乌拉坦麻醉的鸣禽黄雀（Ｃａｒｄｕｅｌｉｓ ｓｐｉｎｕｓ）。观察了电及化学刺激新纹状体前部大细胞核外侧部（１ＭＡＮ）对发声和呼吸的影响。结果如下：（１）电刺激１ＭＡＮ的不同区域都引起鸣叫反应。（２）长串电脉冲刺激１ＭＡＮ使呼吸频率增加,呼吸幅度降低。（３）短串电脉冲刺激１ＭＡＮ,落位于吸气相,产生吸气要断效应;落位于呼气相,可使呼气时程延长,以冲刺激１ＭＡＮ,落位于吸气相,产生吸气切断效应     

Inspiratory muscle activity during bird song

The apparently continuous flow of bird song is in reality punctuated by brief periods of silence during which there are short inspirations called minibreaths. To determine whether these minibreaths are accompanied, and thus perhaps caused, by activity in inspiratory muscles, electromyographic (EMG) activity was recorded in M. scalenus in zebra finches and in M. scalenus and Mm. levatores costarum in cowbirds, together with EMGs from the abdominal expiratory muscles, air sac pressure and tracheal airflow. EMG activity in Mm. scalenus and levatores costarum consistently preceded the onset of negative air sac pressure by ∼11 ms during both quiet respiration and singing in both species. The electrical activity of these two muscles was very similar. Compared with during quiet respiration, the amplitude of inspiratory muscle EMG during singing was increased between five- and 12-fold and its duration was decreased from >200 ms to on average 41 ms during minibreaths, again for both species, but inspiratory muscle activity did not overlap with that of the expiratory muscles. Thus, there was no indication that the inspiratory muscles acted either to shorten the duration of expiration or to reduce the expiratory effort as might occur if both expiratory and inspiratory muscles were simultaneously active. Inspiratory and expiratory muscle activities were highly stereotyped during song to the extent that together, they defined the temporal pattern of the songs and song types of individual birds. © 1998 John Wiley & Sons, Inc. J Neurobiol 36: 441–453, 1998     

Opiate slowing of feline respiratory rhythm and effects on putative medullary phase-regulating neurons

Opiates have effects on respiratory neurons that depress tidal volume and air exchange, reduce chest wall compliance, and slow rhythm. The most dose-sensitive opioid effect is slowing of the respiratory rhythm through mechanisms that have not been thoroughly investigated. An in vivo dose-response analysis was performed on medullary respiratory neurons of adult cats to investigate two untested hypotheses related to mechanisms of opioid-mediated rhythm slowing: 1) Opiates suppress intrinsic conductances that limit discharge duration in medullary inspiratory and expiratory neurons, and 2) opiates delay the onset and lengthen the duration of discharges postsynaptically in phase-regulating postinspiratory and late-inspiratory neurons. In anesthetized and unanesthetized decerebrate cats, a threshold dose (3 microg/kg) of the mu-opioid receptor agonist fentanyl slowed respiratory rhythm by prolonging discharges of inspiratory and expiratory bulbospinal neurons. Additional doses (2-4 microg/kg) of fentanyl also lengthened the interburst silent periods in each type of neuron and delayed the rate of membrane depolarization to firing threshold without altering synaptic drive potential amplitude, input resistance, peak action potential frequency, action potential shape, or afterhyperpolarization. Fentanyl also prolonged discharges of postinspiratory and late-inspiratory neurons in doses that slowed the rhythm of inspiratory and expiratory neurons without altering peak membrane depolarization and hyperpolarization, input resistance, or action potential properties. The temporal changes evoked in the tested neurons can explain the slowing of network respiratory rhythm, but the lack of significant, direct opioid-mediated membrane effects suggests that actions emanating from other types of upstream bulbar respiratory neurons account for rhythm slowing.     

Chronic extracellular recording of fetal medullary neuronal activity

A technique for chronic extracellular recording of neuronal activity in the medullary region of fetal sheep during different sleep states is described. Of 51 recorded neurones, 54% were associated with respiration, blood pressure changes, or muscle electromyograms, and 46% were nonspecific. During apnea (nonrapid-eye-movement sleep) both inspiratory and expiratory neurons had random intermittent activity. Thus apnea is not associated with tonic expiratory neuronal activity.     

Inspiratory neuron activity in the ventrolateral medulla of the dog

The purpose of this study was to describe the distribution and activity pattern of respiratory neurons located in the ventrolateral medulla (VLM) of the dog. Spike activity of 129 respiratory neurons was recorded in 23 ketamine-anesthetized spontaneously breathing dogs. Pontamine blue dye was used to mark the location of each neuron. Most VLM neurons displaying respiratory related spike patterns were located in a column related closely to ambigual and retroambigual nuclei. Both inspiratory and expiratory neurons were present with inspiratory units being grouped more rostrally. The predominant inspiratory neuron firing pattern was "late" inspiratory, although eight "early" types were located. All expiratory firing patterns were the late expiratory variety. Each neuron burst pattern was characterized by determining burst duration (BD), spikes per burst (S/B), peak frequency (PF), time to peak frequency (TPF), rate of rise to peak frequency (PF/TPF), and mean frequency. CO2-induced minute ventilation increases were associated with decreases in BD and TPF and increases in PF, S/B, and PF/TPF. In 11 experiments the relative influences of vagotomy and tracheal occlusion on late inspiratory units were compared. Tracheal occlusion increased late inspiratory BD and S/B but did not alter PF/TPF. Vagotomy increased BD and S/B beyond those obtained by tracheal occlusion and, in some neurons, decreased the PF/TPF. We conclude that the location of respiratory units in the VLM of the dog is similar to that in other species, the discharge pattern of VLM respiratory units is similar to those in cat VLM, and vagotomy and tracheal occlusion affect discharge patterns differently.     

脑桥呼吸调整中枢向中缝大核下行投射的研究

实验在23只苯巴比妥钠麻醉(i.p.30mg/kg)的成年猫上进行。在脑桥呼吸调整中枢(NPBM-KF)共记录到67个单位放电可被电刺激中缝大核(NRM)所逆行兴奋。其中有7个单位为呼吸相关性单位(吸气性6、呼气性1),占脑桥87个呼吸相关性单位总数的8％。逆行兴奋潜伏期在0.4—2.5ms之间,平均1.2ms。中缝大核内微量注入麦角辣根过氧化酶(WGA-HRP)后在NPBM-KF区观察到大量HRP标记神经元。本实验结果表明,发自脑桥呼吸调整中枢神经元的轴突可投射到中缝大核。这一投射通路可能与呼吸及痛觉调节有关。     

Blood pressure changes alter tracheobronchial cough: computational model of the respiratory-cough network and in vivo experiments in anesthetized cats

We tested the hypothesis, motivated in part by a coordinated computational cough network model, that alterations of mean systemic arterial blood pressure (BP) influence the excitability and motor pattern of cough. Model simulations predicted suppression of coughing by stimulation of arterial baroreceptors. In vivo experiments were conducted on anesthetized spontaneously breathing cats. Cough was elicited by mechanical stimulation of the intrathoracic airways. Electromyograms (EMG) of inspiratory parasternal, expiratory abdominal, laryngeal posterior cricoarytenoid (PCA), and thyroarytenoid muscles along with esophageal pressure (EP) and BP were recorded. Transiently elevated BP significantly reduced cough number, cough-related inspiratory, and expiratory amplitudes of EP, peak parasternal and abdominal EMG, and maximum of PCA EMG during the expulsive phase of cough, and prolonged the cough inspiratory and expiratory phases as well as cough cycle duration compared with control coughs. Latencies from the beginning of stimulation to the onset of cough-related diaphragm and abdominal activities were increased. Increases in BP also elicited bradycardia and isocapnic bradypnea. Reductions in BP increased cough number; elevated inspiratory EP amplitude and parasternal, abdominal, and inspiratory PCA EMG amplitudes; decreased total cough cycle duration; shortened the durations of the cough expiratory phase and cough-related abdominal discharge; and shortened cough latency compared with control coughs. Reduced BP also produced tachycardia, tachypnea, and hypocapnic hyperventilation. These effects of BP on coughing likely originate from interactions between barosensitive and respiratory brainstem neuronal networks, particularly by modulation of respiratory neurons within multiple respiration/cough-related brainstem areas by baroreceptor input.     

兔边缘系统隔区呼吸相关神经元

本实验在42只家兔给与 Urethane 半量麻醉,在边缘系统隔区用玻璃微电极方法记录了60个自发的呼吸相关神经元单位放电:吸气型30个单位;呼气型16个单位;跨时相型14个单位。断双侧迷走神经,静脉注入尼克刹米后,呼吸相关神经元单位放电与呼吸节律变化具有伴随性,呈正相关。窒息可以诱发隔区神经元呼吸节律放电。延髓第四脑室局部注入2%Sod。pentothal 后,随呼吸节律抑制、隔区呼吸相关神经元单位放电立即消失。上述结果提示:到达边缘系统隔区的呼吸信息在自主功能及情绪活动的协调方面,可能被认为是有意义的。     

Relationship between respiratory muscle function and age, sex, and other factors

To investigate the effects of gender and age on respiratory muscle function, 160 healthy volunteers (80 males, 80 females) were divided into four age groups. Twenty-eight of the male subjects were smokers. After the subjects were familiarized with the experimental procedure, respiratory muscle strength, inspiratory muscle endurance, and spirometric function, including forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FEV1/FVC, tidal volume, breathing rate, and duty cycle, were measured. The respiratory muscle strength was indicated by the maximal static inspiratory and expiratory pressures (PImmax and PEmmax). Inspiratory muscle endurance was determined by the time the subject was able to sustain breathing against an inspiratory pressure load on a modified Nickerson-Keens device. The results showed that 1) except for inspiratory muscle endurance and FEV1/FVC, men had greater respiratory muscle and pulmonary functions than women, 2) respiratory muscle function and pulmonary function decreased with age, 3) smoking tended to lower duty cycle and FEV1/FVC and to enhance PE,mmax, and 4) inspiratory muscle endurance was greater in men who were physically active than in those who were sedentary. Therefore we conclude that there are sexual and age differences in respiratory muscle strength and pulmonary function and that smoking or physical activity may affect respiratory muscle function.     

Effects of pulse lung inflation on chest wall expiratory motor activity.

The effects of pulse lung inflation (LI) on expiratory muscle activity and phase duration (Te) were determined in anesthetized, spontaneously breathing dogs (n = 20). A volume syringe was used to inflate the lungs at various times during the expiratory phase. The magnitude of lung volume was assessed by the corresponding change in airway pressure (Paw; range 2-20 cmH(2)O). Electromyographic (EMG) activities were recorded from both thoracic and abdominal muscles. Parasternal muscle EMG was used to record inspiratory activity. Expiratory activity was assessed from the triangularis sterni (TS), internal intercostal (IIC), and transversus abdominis (TA) muscles. Lung inflations <7 cmH(2)O consistently inhibited TS activity but had variable effects on TA and IIC activity and expiratory duration. Lung inflations resulting in Paw values >7 cmH(2)O, however, inhibited expiratory EMG activity of each of the expiratory muscles and lengthened Te in all animals. The responses of expiratory EMG and Te were directly related to the magnitude of the lung inflation. The inhibition of expiratory motor activity was independent of the timing of pulse lung inflation during the expiratory phase. The inhibitory effects of lung inflation were eliminated by bilateral vagotomy and could be reproduced by electrical stimulation of the vagus nerve. We conclude that pulse lung inflation resulting in Paw between 7 and 20 cmH(2)O produces a vagally mediated inhibition of expiratory muscle activity that is directly related to the magnitude of the inflation. Lower inflation pressures produce variable effects that are muscle specific.     

非NMDA受体参与双相呼气和吸气神经元电活动的调节

在新生大鼠延髓脑片上同步记录舌下神经根和双相呼气神经元／吸气神经元单位的放电活动,并在灌流的改良Kredbs液中先后加以非NMDA受体的激动剂KA和拮抗剂DNQX,观察对神经元单位放电的影响,以进一步探讨非NMDA受体在对双相呼气神经元之间交互兴奋和吸气神经元兴奋性突触输入中的作用,结果表明,使用非NMDA受体激动剂KA以后,双相呼气神经元的放电频率和蜂频率都明显增大,吸气神经元中期放电的频率和非NMDA受体激动剂KA以后,双相呼气神经元的放电频率和峰频率都明显增大,吸气神经元中期放电的频率和峰频率也显著增大,而早期和晚期放电的频率无明显改变,用相应拮抗剂以后,上述效应明显被抑制,结果提示,非NMDA受体参与了双相呼气神经元之间的交互兴奋作用,并且也介导了吸气神经元的兴奋性突触输入／