KF核及B(o)tzinger复合体内GABA能神经元向膈神经核的投射

实验在６只成年猫上进行。将ＷＧＡ－ＨＲＰ微量注入Ｃ５膈神经核内,通过逆行追踪及ＧＡＢＡ免疫组织化学ＦＩＴＣ荧光双重标记方法,研究了脑干内ＧＡＢＡ能神经元向膈神经核的投射。结果在脑桥ＫＦ核和面神经后核周围区（即Ｂｏｔｚｉｎｇｅｒ复合体）观察到ＧＡＢＡ－ＨＲＰ双标神经元。另外,在中缝大核、旁巨细胞外侧核及前庭神经核也观察到双标神经元。本实验结果表明：发自上述脑干神经核团,特别是ＫＦ核及Ｂｏｔｚｉｎｇｅ     

大鼠杏仁基底外侧核腹侧部向杏仁中央核的纤维投射──HRP逆行示踪结合免疫组织化学法研究

本实验采用ＨＲＰ逆行示踪结合免疫组织化学方法,对大鼠杏仁底基底外侧核腹侧部向中央杏仁核的纤维投射特征及其化学特性进行了研究。一侧杏仁中央核（Ｃｅ）内注射ＨＲＰ后,于双侧杏仁基底外侧核腹侧部（ＢＬＶ）观察到大量ＨＲＰ标记神经元,以对侧为主;在杏仁基底外侧核前（ＢＬＡ）、后（ＢＬＰ）部及梨状皮质内侧部（ＰＣＭ）第Ⅱ、Ⅲ层仅观察到少量ＨＲＰ标记神经元。当注射范围局限于杏仁中央核内侧部（ＣｅＭ）,ＢＬＶ的标记神经元相对多．当注射范围局限于杏仁中央核外侧部（ＣｅＬ）,ＢＬＶ的标记神经元相对少。将有ＨＲＰ标记神经元的切片分别与生长抑素（ＳＯＭ）、脑啡呔（ＥＮＫ）、Ｐ物质（ＳＰ）抗血清按ＡＢＣ法完成免疫组织化学反应,结果在ＢＬＶ、ＰＣＭ第Ⅱ、Ⅲ层观察到ＨＲＰ－ＳＯＭ免疫阳性双标记神经元,但未发现ＨＲＰ－ＳＰ、ＨＲＰ－ＥＮＫ免疫阳性双标记神经元;在ＢＬＡ和ＢＬＰ未发现ＨＲＰ－ＳＯＭ、ＨＲＰ－ＥＮＫ、ＨＲＰ－ＳＰ免疫阳性双标记神经元。本文着重讨论了ＢＬＶ与内脏功能活动的关系,认为ＢＬＶ不同于ＢＬＡ与ＢＬＰ,它参与“内脏环路”。此外,还分析了ＰＣＭ投射到Ｃｅ的神经元的功能学意义。     

印防己毒素对Btzinger复合体吸气抑制的阻断作用

Ｂｏｔｚｉｎｇｅｒ复合体（Ｂｏｔ．Ｃ）以呼气递增型神经元为主,其轴突广泛投射到延髓及脊髓呼吸神经元群,是吸气神经元呼气相突触后抑制的来源,在呼吸节律形成中起关键性作用。然而关于其吸气抑制的递质基础尚不清楚。尽管有资料表明Ｂｏｔ．Ｃ神经元为ＧＡＢＡ能,...     

正常豚鼠耳蜗核一氧化氮合酶阳性神经元的投射

本文采用辣根过氧化物酶（ＨＲＰ）逆行追踪技术结合硫辛酰胺脱氨酸（ＮＡＤＰＨ－ｄ）组织化学方法,研究正常豚鼠耳蜗核一氧化氮合酶（ＮＯＳ）阳性神经元的上行投射特点。探讨耳蜗核ＮＯＳ阳性神经元在听觉信号传递中的可能作用。结果表明,一侧上橄榄复合体加压注射ＨＲＰ后,两侧耳蜗核均出现ＨＲＰ标记细胞,同侧耳蜗核ＮＯＳ－ＨＲＰ双标细胞较多占８２．６３％,并可见ＨＲＰ阳性纤维和终末包绕ＮＯＳ阳性胞体,对侧耳蜗核ＮＯＳ－ＨＲＰ双标细胞相对较少,仅占１４．８７％。一侧下丘加压注入ＨＲＰ后两侧耳蜗核均无ＨＲＰ－ＮＯＳ双标细胞。结果提示,耳蜗核ＮＯＳ阳性神经元向上橄榄复合体投射,可能具有调节听觉声信号传递的作用     

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。     

胃肠道伤害性刺激诱导中缝背核触液神经元Fos表达

本文以ＣＢ－ＨＲＰ逆行追踪和原癌基因ｃ－ｆｏｓ表达技术相结合,观察胃肠道伤害性刺激后中缝背核触液神经元Ｆｏｓ的表达。在中缝背核发现三种标记神经元,包括ＣＢ－ＨＲＰ逆行标记神经元（３０８）、Ｆｏｓ阳性神经元（４２）和ＣＢ－ＨＲＰ／Ｆｏｓ双重标记神经元（５）。本研究提示中缝背核含有一些具有双重功能的神经元,它们既在脑－脑脊液神经体液回路中传递信息,又在胃肠道伤害性刺激的中枢传递和功能调控中起一定的作用     

延髓嘴端包氏复合体与中枢呼吸节律形成

包氏复合体是一群位于延髓嘴端面神经后核腹内侧的呼气神经元。该群神经元为抑制性,轴突广泛投射到脑干呼吸相关结构及膈神经神经元群。本研究室动用微电刺激、逆行兴奋、ＷＧＡ－ＨＲＰ标记、微量注射等技术研究了该结构在呼吸时相转换及呼吸节律形成中的作用。结果显示：包氏复合体怀脑干呼吸神经元群之间存在双向纤维联系,该结构参与吸气向呼气以及呼气向吸气的时相转换,且在呼气相形成中起重要作用。     

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。     

KF核及Btzinger复合体内GABA能神经元向膈神经核的投射

实验在 6只成年猫上进行。将WGA HRP微量注入C5膈神经核内 ,通过逆行追踪及GABA免疫组织化学FITC荧光双重标记方法 ,研究了脑干内GABA能神经元向膈神经核的投射。结果在脑桥KF核和面神经后核周围区 (即B¨otzinger复合体 )观察到GABA HRP双标神经元。另外 ,在中缝大核、旁巨细胞外侧核及前庭神经核也观察到双标神经元。本实验结果表明 :发自上述脑干神经核团 ,特别是KF核及B¨otzinger复合体的GABA能神经元的轴突可投射到膈神经核     

黄雀、黄喉鵐角状核和层状核的听觉通路及比较

鸟类的角状核（ＮＡ）和层状核（ＮＬ）是延髓内司听觉及声源定位的重要感觉中枢。本文用ＨＲＰ顺、逆行追踪方法,对鸣禽类黄雀（Ｃａｒｄｕｅｌｉｓ ｓｐｉｎｕｓ）与黄喉（Ｅｍｂｅｒｉｚａ ｅｌｅｇａｎｓ）的ＮＡ及ＮＬ的神经通路进行了研究与比较。发现ＮＡ接受听神经的传入并投射至脑桥外侧匠系核复合体及中脑背外测核的背部;ＮＬ接受巨细胞核的传入并以不同的行径投射至脑桥和中脑的不同部位。它们的行径是各自独立的。提示这两条通路在听觉及声源定位等方面是各自分工的。     

Respiratory reactions on microinjections of GABA and baclofen into the Bötzinger complex and the pre-Bötzinger complex in rats

In adult anaesthetized rats the respiratory reactions to microinjections of GABA (10(-5) M) and baclofen (10(-6) M) into Botzinger complex (BC) and pre-Botzinger complex (PBC) were investigated. It was shown, that GABA microinjections into BC shortened inspiratory time and extended expiratory time while respiratory rate was not changed essentially, under this conditions the tidal volume and ventilation were increased. GABA microinjections into PBC significantly inhibited respiratory rhythm due to inspiratory and expiratory time prolongations and reduced tidal volume. The microinjections of baclofen into BC reduced expiration time and ventilation, and increased respiratory frequency whereas microinjections into PBC increased tidal volume without respiratory rate and expiratory time changes. It is suggested that the reactions observed demonstrate the various contribution of GABAergic mechanisms, including GABA(B)-receptors within BC and PBC, in control of respiratory pattern parameters.     

家兔单侧、双侧B(o)tzinger复合体内微量注射甘氨酸及士的宁对膈神经放电的影响

实验在３４只氨基甲酸乙酯麻醉,断双侧瞳神经,肌松,人工通气的家兔上进行。单侧和双侧Ｂｏｔｚｉｎｇｅｒ复合体内微量注射抑制性神经递质甘氨酸及其受体阻断剂 宁,观察膈神经放电的变化。     

The effect of leu-enkephalin on membrane potential and activity of the rat respiratory center neurons in vitro

In frontal brainstem slices of Wistar rats, the whole-cell patch-clamp recordings showed the effect of opioid peptide leu-enkephalin (10 nM-1 microM) on membrane potential and spontaneous activity pattern of neurons in two divisions of the respiratory center, ventro-lateral area of the solitary tract nucleus, and the pre-B?tzinger complex. Leu-enkephalin induced a membrane hyperpolarization of the respiratory centre neurons and reduction of the spike activity level in spontaneously active units. After administration of leu-enkephalin, a decrease in frequency of bursts was found in bursting cells of the pro-B?tzinger complex; in two cases, there was a transition of bursting activity to tonic one. The data suggest that the mechanism of the central respiratory activity of leu-enkephalin is based on its direct action at the level of membrane of the respiratory centre neurons.     

Spinal projections of brainstem respiratory related neurons in the cat as revealed by retrograde fluorescent markers

By means of retrograde axonal transport of fluorescent tracers, connections between brainstem respiratory related regions and the spinal cord has been studied in the cat. Neurons at the pneumotaxic center project bilaterally (90% ipsi-, 10% contra-) to cervical and lumbar spinal cord and ipsilaterally to thoracic levels. The ventrolateral nucleus of the tractus solitarius project mainly contralaterally (85%) to cervical levels and only contralaterally to thoracic levels; no efferent projections were found to lumbar levels. The ventral respiratory group showed a great number of neurons projecting to the spinal cord especially from the nucleus retroambiguus. Both nuclei, ambiguus and retroambiguus, project mainly contralaterally (70%) to the spinal cord. The B?tzinger complex showed rather scarce bilateral projections to cervical and only ipsilateral projections to lower cervical, thoracic and lumber levels.     

Effect of leu-enkephalin on potassium currents in neurons of the respiratory center of rats in vitro

Action of opioid peptide: leu-enkephalin (10 nM - 1 microM), on K+A-current and inward rectifier in neurons of two divisions of the respiratory center: ventrolateral area of the solitary tract nucleus and the pre-Botzinger complex, was investigated in brainstem slices of Wistar rats by whole-cell voltage-clamp recordings. A-current and inward rectifier were found in all the neurons under study. A-current did not change after the application of leu-enkephalin to the bath solution while the amplitude of inward rectifier did reversibly increase. The data obtained suggest that the inhibitory effect of leu-enkephalin on neurons of the respiratory center, at least in part, can be based on its ability to modulate inward rectifier.     

Distribution of Fos-Like Immunoreactivity,Catecholaminergic and Serotoninergic Neurons Activated by the Laryngeal Chemoreflex in the Medulla Oblongata of Rats

The laryngeal chemoreflex (LCR) induces apnea, glottis closure, bradycardia and hypertension in young and maturing mammals. We examined the distribution of medullary nuclei that are activated by the LCR and used immunofluorescent detection of Fos protein as a cellular marker for neuronal activation to establish that the medullary catecholaminergic and serotoninergic neurons participate in the modulation of the LCR. The LCR was elicited by the infusion of KCl-HCl solution into the laryngeal lumen of adult rats in the experimental group, whereas the control group received the same surgery but no infusion. In comparison, the number of regions of Fos-like immunoreactivity (FLI) that were activated by the LCR significantly increased in the nucleus of the solitary tract (NTS), the vestibular nuclear complex (VNC), the loose formation of the nucleus ambiguus (AmbL), the rostral ventral respiratory group (RVRG), the ventrolateral reticular complex (VLR), the pre-Bötzinger complex (PrBöt), the Bötzinger complex (Böt), the spinal trigeminal nucleus (SP5), and the raphe obscurus nucleus (ROb) bilaterally from the medulla oblongata. Furthermore, 12.71% of neurons with FLI in the dorsolateral part of the nucleus of the solitary tract (SolDL) showed tyrosine hydroxylase-immunoreactivity (TH-ir, catecholaminergic), and 70.87% of neurons with FLI in the ROb were serotoninergic. Our data demonstrated the distribution of medullary nuclei that were activated by the LCR, and further demonstrated that catecholaminergic neurons of the SolDL and serotoninergic neurons of the ROb were activated by the LCR, indicating the potential central pathway of the LCR.     

Parvalbumin in respiratory neurons of the ventrolateral medulla of the adult rat

A column of parvalbumin immunoreactive neurons is closely associated with the location of respiratory neurons in the ventrolateral medulla of the rat. The majority (66%) of bulbospinal neurons in the medullary ventral respiratory column (VRC) that were retrogradely labeled by tracer injections in the phrenic nucleus were also positive for parvalbumin. In contrast, only 18.8% of VRC neurons retrogradely labeled after a tracer injection in the VRC, also expressed parvalbumin. The average cross-sectional area of VRC neurons retrogradely labeled after VRC injections was 193.8 μm² ± 6.6 SE. These were significantly smaller than VRC parvalbumin neurons (271.9 μm² ± 12.3 SE). Parvalbumin neurons were found in the Bötzinger Complex, the rostral ventral respiratory group (VRG), and the caudal VRG, areas which all contribute to the bulbospinal projection. In contrast, parvalbumin neurons were sparse or absent in the preBötzinger Complex and in the vicinity of the retrotrapezoid nucleus, areas that have few bulbospinal projections. Parvalbumin was rarely colocalized within Neurokinin-1 receptor positive (NK1R) VRC neurons, which are found in the preBötzinger complex and in the anteroventral part of the rostral VRG. Parvalbumin neurons in the Bötzinger Complex and rostral VRG help define the rostrocaudal extent of these regions. The absence of parvalbumin neurons from the intervening preBötzinger complex also helps establish the boundaries of this region. Regional boundaries described in this manner are in good agreement with earlier physiological and anatomical studies. Taken together, the distributions of parvalbumin, NK1R and bulbospinal neurons suggest that the rostral VRG may be subdivided into distinct, anterodorsal, anteroventral, and posterior subdivisions.     

Structural Types of Spinal Cord Marginal (Lamina I) Neurons Projecting to the Nucleus of the Tractus Solitarius in the Rat

The structural types of spinal cord marginal (lamina I) neurons projecting to the nucleus of the tractus solitarius (NTS) were studied. Upon injections of cholera toxin subunit B (CTb) into the caudal part of the NTS, including its lateral and medial portions, labeled cells occurred bilaterally in laminae I, IV-VII, and X, and the lateral spinal nucleus (LSN). After injections into the lateral portion alone, only a few cells were labeled in laminae V, VII, and X, and the LSN, and none in the superficial dorsal horn. Of 1882 labeled marginal cells, 38% belonged to the flattened type, 37% to the pyramidal type, and 25% to the fusiform type. Flattened and pyramidal cells were labeled in considerably greater numbers than those reported when other supraspinal targets of these cells were injected with CTb. Since cells in the NTS are known to be under marked 7-aminobutyric acidergic (GABA-ergic) inhibition, it is possible that only strong input conveyed by great numbers of flattened and pyramidal cells is capable of overcoming that barrier. Fusiform cells were labeled in numbers similar to those observed previously after tracer injections into the two other targets of this neuronal type, the parabrachial nuclei and the lateral reticular nucleus. Considering that these regions, as well as the NTS, control cardiovascular and respiratory functions, it is suggested that fusiform cells transmit noxious input that will influence autonomic reflexes processed in the three nuclei.