大鼠灰翼区微量注射6-羟多巴胺对迷走-迷走抑胃反射的影响

本文用乌拉坦麻醉的大鼠,观察了灰翼区微量注射6-羟多巴胺(6-OHDA)对迷走-迷走抑胃反射的影响。实验动物分三组:空白对照组、溶媒组和6-OHDA 组。实验结果表明,在溶媒组刺激迷走神经中枢端使胃电慢波的振幅和胃内压分别下降到刺激前对照值的36.87±22.07%和32.52±25.41%,与空白对照组相比无显著的差异(P>0.05)。但是,在6-OHDA组,刺激迷走神经中枢端对胃电和胃运动的抑制效应明显减弱,慢波的振幅与胃内压分别下降到刺激前对照值的67.48±13.21%和50.88±21.40%,同溶媒组相比有非常显著的差异(P<0.01)。结果提示,延髓灰翼区的儿茶酚胺能神经参与迷走-迷走抑胃反射的中枢机制。     

刺激大鼠蓝斑核区对胃电和胃运动的影响

用乌拉坦麻醉的大鼠,同步描记血压、胃电和胃运动,观察了刺激蓝斑核区对胃电和胃运动的影响,分析了其作用途径。实验结果表明,刺激蓝斑核区后血压平均升高60.5mmHg(P<0.001);胃电慢波的振幅由对照的0.52mV 减弱到0.18mV(P<0.001)。快波的振幅和频率也减少。胃内压平均下降到对照值的29.9％(P<0.001)。在横断颈髓的动物刺激蓝斑核区后血压的升高幅度明显减弱,平均升高9mmHg,升压效应的潜伏期明显延长;胃电慢波的振幅由对照的0.53mV 减弱到 0.24mV(P<0.001)。胃内压平均下降到对照值的45.1％。对胃电和胃运动的这种抑制效应可被切断迷走神经所完全消除。在事先切断迷走神经但脊髓仍保留完整的动物,刺激蓝斑核区使胃内压平均下降36.6％(P<0.01)。根据以上结果认为,蓝斑核区可能参与对胃电和胃运动的中枢性调节。此调节机制可能经由脊髓和迷走两条通路实现。     

蓝斑对迷走—心血管反射的影响

实验用家兔３６只,采用低频和高频电流刺激颈部迷走神经中枢端,建立迷走－减压和迷走－升压反射,两种频率电刺激均导致肾交感神经传出活动减少。以迷走－血压反射和迷走－交感反射为指标,连续电流刺激蓝斑或ＬＣ微量注射谷氨酸钠均抑制迷走－血压反射和迷走－交感反射。     

大鼠蓝斑核对血压和迷走加压反应的影响

我们观察电刺激大鼠蓝斑核对血压和迷走—加压反应的影响,其结果简述如下:一、电刺激大鼠单侧蓝斑(17只)及双侧蓝斑(27只)均引起明显的加压反应,后者更为显著。二、同时电刺激蓝斑核与迷走神经向中端引起极明显的加压反应。三、损毁垂体及切除双侧肾上腺届,蓝斑加压反应明显减弱。四、烧毁双侧蓝斑核,迷走—加压反应消失。据此我们认为迷走一加压反应可能包含蓝斑核所释放的去甲肾上腺素的作用。     

大鼠蓝斑核区神经降压素对迷走—加压反应的影响

本文应用放射免疫、核团微量注射及组织荧光分光测定等实验方法,研究大鼠蓝斑核区神经降压素对迷走-加压反应的影响。结果表明:1.电刺激颈迷走神经向中端,孤束核、蓝斑核区和下丘脑中神经降压素免疫活性物的含量明显增高(p<0.05)。2.蓝斑核区注入神经降压素后,刺激颈迷走神经向中端,迷走-加压反应明显减弱(P<0.01),并呈明显的量效依赖关系。3.蓝斑核区注入抗神经降压素血清,迷走-加压反应明显加强(p<0.01)。4.蓝斑核区注入神经降压素后,刺激颈迷走神经向中端,该区去甲肾上腺素含量明显增高(p<0.05)。以上结果提示:内源与外源性神经降压素参与迷走-加压反应的调节过程,并可能与神经降压素引起蓝斑核区去甲肾上腺素含量增加有关。     

蓝斑对迷走─心血管反射的影响

实验用家兔３６只,采用低频（５－８Ｈｚ）和高频（５０－１００Ｈｚ）电流刺激颈部迷走神经中枢端（ＶＡＳ）,建立迷走－减压和迷走－升压反射,两种频率电刺激均导致肾交感神经传出活动（ＲＳＡ）减少。以迷走－血压反射和迷走－交感反射为指标,连续电流刺激蓝斑（ＬＣ）或ＬＣ微量注射谷氨酸钠均抑制迷走－血压反射和迷走－交感反射。而连续电流刺激ＬＣ或ＬＣ微量注射谷氨酸钠本身均引起平均动脉血压升高和ＲＳＡ增加。本文对新近提出的对ＬＣ整体功能认识的理论,结合本文的结果进行了讨论     

蓝斑核和中缝背核参与电刺激弓状核引起的大鼠胃内压降低的反应

选用 Wistar 大鼠80只。在乌拉坦麻醉下观察了电刺激弓状核对胃内压的影响并初步分析了其作用的中枢途径。结果为:(1)刺激时,胃内压显著降低;(2)分别电解损毁双侧蓝斑核和中缝背核,均可减弱弓状核的这一作用;(3)侧脑室注射纳洛酮不影响弓状核的这一作用。上述结果表明,电刺激弓状核降低胃内压的作用需有蓝斑核和中缝背核参与,而弓状核内富含的β-内啡肽能神经元可能与这一作用无关。     

纳洛酮对家兔迷走-加压反应的影响

本文观察了刺激家兔颈迷走神经中枢端所引起的加压反应(迷走-加压反应)和侧脑室内注射纳洛酮对家兔迷走-加压反应的影响,结果表明:刺激家兔颈迷走神经中枢端而引起的加压反应可为侧脑室注射纳洛酮后而抑制,这提示内源性阿片样物质参与家兔的迷走-加压反应过程。     

激活蓝斑在孤束核水平对迷走神经传入的抑制

在戊巴比妥钠麻醉兔,电刺激颈迷走神经中枢端,在同侧孤束核（NTS）区可记录到一个由三个子波组成的复合电位。它们的潜伏期分别为6．8±0．6ms（P1）,25．8±4．2ms（P2）和89．1±2．7ms（P3）。这可能代表着不同性质的迷走传入纤维的突触后电位。同侧蓝斑（LC）内微量注射谷氨酸钠使P2,P3波的幅值明显降低。电刺激LC在同侧NTS区诱发出111个有反应单位,其潜伏期平均为6．3±1．4ms。在169个对迷走传入刺激有反应的NTS单位中,有90个对LC刺激也有反应。39个（占43．3％）会聚性单位对上述两种刺激的反应相似,而其余的呈不同的反应。对LC和迷走刺激分别均呈兴奋反应的25个NTS单位中,如预先刺激LC,则有14个单位对迷走刺激的兴奋反应受到明显抑制,另11个单位的兴奋反应完全被抑制。上述结果提示：激活蓝斑核具有抑制NTS对迷走传入刺激反应的作用。     

尾核P物质对胃运动的抑制效应系通过黑质,迷走背核经迷走神经所介导

本工作观察损毁下丘脑外侧区,黑质,迷走背核及其传出神经对尾核微量注射Ｐ物质引起的胃肌电快波和胃运动抑制效应的影响。实验结果：该抑制效应不依赖于下丘脑外侧区的完整但可被损毁黑质,迷走背核或迷走上所消除。用利血平耗竭交感神经递质则不影响该效应。这些结果表明：尾核ＳＰ的抑胃效应系通过黑质、迷走背核经迷走神经所传出。     

Neuropeptides as central integrators of autonomic nerve activity: effects of TRH, SRIF, VIP and bombesin on gastric and adrenal nerves

The nerve activity of the gastric ramus of the splanchnic (sympathetic) nerve, gastric ramus of the vagus, adrenal ramus of the splanchnic nerve and the superior laryngeal nerve (laryngeal ramus of vagus) were assessed before and after i.c.v. injection of neuropeptides in the rat. TRH stimulated the vagal branch but attenuated the sympathetic outflow to the stomach. In contrast, the sympathetic outflow to the adrenal was enhanced by TRH. SRIF suppressed the activity of all the nerves studied. VIP did not affect the sympathetic outflow to the stomach while suppressing the gastric branch of the vagus. The adrenal sympathetic branch as well as the superior laryngeal nerve was stimulated by VIP. Bombesin suppressed both vagal and sympathetic outflow to the stomach but markedly stimulated the laryngeal branch of the vagus. The adrenal sympathetic nerve was either stimulated or attenuated slightly by bombesin. These results indicate that centrally administered neuropeptides produce reactions specific for each nerve.     

Neuronal organization of coeruleo-spinal connections in cats

Experiments on cats showed that electrical stimulation of the locus coeruleus leads to diminution of the inhibitory action of flexor reflex afferents (FRA) on the extensor monosynaptic reflex and to a decrease in amplitude of the IPSP evoked by FRA in extensor motoneurons. Injection of microdoses of aspartic acid and chlorpromazine into the locus coeruleus depresses the inhibitory effects of FRA, whereas injections of procaine and noradrenalin potentiate the inhibitory action of FRA. Data are given on the character of the descending influence of the locus coeruleus on different groups of spinal interneurons. It is concluded that depression of the inhibitory action of FRA is effected at the level of the final inhibitory interneurons of the "FRA system."A. A. Bogolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 16, No. 3, pp. 362–374, May–June, 1984.     

Effect of electric stimulation of the locus coeruleus on transcallosal response in parietal associative cortex of the cat brain

The influence of conditioning locus coeruleus (LC) stimulation on various components of transcallosal field response was investigated in the parietal cortex of the cat brain. Conditioning LC simulation caused a decrease in fast positive wave amplitude and facilitated slow negative wave. It is concluded that LC suppresses excitatory and facilitates inhibitor processes evoked in the parietal cortex by transcallosal stimulation.     

Correlations between variations of electrical field at the body surface and contractions of the stomach in guinea pig.

1. The slow potentiel changes of the base line of the electrocardiogram recorded by cutaneous electrodes, here called EGEG (electrogastroenterogram) have been recorded simultaneously with the electromyogram and pressure variations of the stomach antrum. 2. Periodic fluctuations of EGEG, 400 microV amplitude, were correlated with activities of the antrum EMG consisting of 3 to 6 mV spikes superimposed on slow wave of depolarization, and with gastric intraluminal pressure of 5 to 7 cm of water. 3. An anticholinergic drug abolished all those activities. A gastric contracture flattened the EGEG. 4. Rhythmic distensions of the antrum induced a synchronous modulation of EGEG, the magnitude of which was correlated with the amplitude of distension. These result suggest that the origin of EGEG is essentially the movements of stomach.     

电刺激家兔迷走神经中枢端诱导的黑-伯反射中的非联合型学习现象

本文旨在研究电刺激家兔迷走神经诱导的黑-伯（Hering-Breuer,HB）反射中的学习和记忆现象。选择性电刺激家兔迷走神经中枢端（频率10～100Hz,强度20～60μA,波宽0．3ms,持续60s）,观察对膈神经放电的影响。以不同频率电刺激家兔迷走神经可模拟HB反射的两种成分,即类似肺容积增大所致抑制吸气的肺扩张反射和类似肺容积缩小所致加强吸气的肺萎陷反射。（1）长时高频（≥40Hz,60s）电刺激迷走神经可模拟呼吸频率减慢,呼气时程延长的肺扩张反射。随着刺激时间的延长,膈神经放电抑制的程度逐渐衰减,表现为呼吸频率的减慢（主要由呼气时程延长所致）在刺激过程中逐渐减弱或消失,显示为适应性或“习惯化”的现象;刺激结束时呼吸运动呈现反跳性增强,表现为一过性的呼气时程缩短,呼吸频率加快,然后才逐渐恢复正常。长时低频（〈40Hz,60s）电刺激迷走神经可模拟呼吸频率加快、呼气时程缩短的肺萎陷反射。随着刺激时间的延长,膈神经放电增强的程度逐渐衰减,同样表现出“习惯化”现象;刺激结束后,膈神经放电不是突然降低,而是继续衰减,表现为呼气时程逐渐延长,呼吸频率逐渐减慢,直至恢复到前对照水平,表现了刺激后的短时增强效应。（2）HB反射的适应性或“习惯化”程度反向依赖于刺激强度和刺激频率,表现为随着刺激强度和频率的增加,膈神经放电越远离正常基线水平,即爿惯化程度减弱。结果表明,家兔HB反射具有“习惯化”这一非联合型学习现象,反映与其有关的呼吸神经元网络具有突触功能的可翅性,呼吸的中枢调控反射具有一定的适应性。     

蓝斑核、中缝大核和迷走神经背核在胃运动调节中的关系

目的：探讨蓝斑（LC）、中缝大核（NRM）和迷走神经背核（DMV）,及其相关递质和受体对胃运动的调节途径及机制,阐明它们在调节胃运动中的相互关系。方法：实验采用了核团定位电刺激、损毁和核团微量注射等实验方法,以记录胃内压,统计胃收缩幅度作为胃运动变化的指标。结果：①刺激LC显著降低胃收缩幅度（P〈0.01）,损毁DMV可以减弱此效应,而阻断DMV上的肾上腺素能α受体,可以反转此抑胃效应。②刺激NRM显著降低胃收缩幅度（P〈0.01）,损毁DMV后此效应被消除;阻断DMV上的5-HT2A受体使胃收缩幅度大幅度降低（P〈0.01）,此时再刺激NRM不能进一步的抑制胃运动;而损毁LC后刺激NRM,可消除NRM的抑胃效应,在LC注射5-HT2A受体阻断剂也可以消除该效应。结论：①LC可能通过DMV的5-HT2A受体和α受体对生理条件下正常胃的运动起着重要的双向调节作用;②NRM通过LC上的5-HT2A受体而发挥其对胃运动的抑制效应。     

刺激迷走神经和酸化十二指肠对狗胰液分泌的相互影响

用5条制备有 Thomas 胰瘘和胃瘘的狗作慢性麻醉实验,观察刺激迷走神经和酸化十二指肠对胰液分泌的相互影响,结果如下:1.在酸化肠的情况下,刺激迷走神经所引起的胰蛋白质和碳酸氢盐的排出量显著增多,其效应超过单独刺激迷走神经和酸化肠所产生效应之和。2.在酸化肠引起胰分泌停止后的短时间内,再刺激迷走神经,胰液分泌的潜伏期缩短,蛋白质和碳酸氢盐排出量增多。3.阻断迷走冲动或注射阿托品后,酸化肠所引起胰液的分泌明显减少。4.用利多卡因麻痹肠粘膜后,酸化肠所引起胰液的分泌也明显降低。这些结果提示,在酸化十二指肠引起胰液分泌的机制中,有迷走神经和局部神经参与,迷走冲动和促胰液素及促胰酶素共同作用靶器官时,有相互加强作用,一旦迷走冲动被阻断,这两种激素的作用即明显降低。     

Effects of repetitive stimulation of the locus coeruleus on spinal inhibitory responses to suprasegmental stimulation in cats

Effects of repetitive stimulation of the locus coeruleus on spinal responses to activation of cortico-, reticulo-, and vestibulospinal tracts were studied in decerebellate cats anesthetized with chloralose. Descending influences of these structures were assessed from changes in amplitude of extensor and flexor monosynaptic discharges or from the magnitude of postsynaptic potentials recorded from the corresponding motoneurons. Stimulation of the motor cortex or modullary reticular formation as a rule evoked two-component inhibitory responses in extensor motoneurons and excitatory-inhibitory responses in flexor motoneurons. Stimulation of locus coeruleus effectively depressed the amplitude of the late component and, to a lesser degree, that of the early component of inhibition arising after stimulation of the cerebral cortex or reticular formation. During stimulation of the locus coeruleus no marked changes were found in inhibitory responses evoked by vestibulospinal influences in flexor motoneurons, and also in excitatory responses arising after stimulation of the above-mentioned descending pathways in both groups of motoneurons.