Changes in cat medullary neurone firing rates and synchrony following induction of respiratory long-term facilitation.
Changes in cat medullary neurone firing rates and synchrony following induction of respiratory long-term facilitation.
复制标题
诱导呼吸长期促进后，猫髓质神经元放电率和同步性的变化。
DOI：
10.1111/j.1469-7793.2001.0483f.x
复制
发表时间：
2001
期刊：
影响因子：
--
通讯作者：
Lindsey,BG
中科院分区：
文献类型：
--
作者：
Morris,KF;Shannon,R;Lindsey,BG
长期易化是一种呼吸记忆，表现为运动输出的增加持续超过一小时。这种变化是由反复缺氧、刺激颈动脉化学感受器或电刺激颈动脉窦神经或脑干中线引起的。目前的工作解决了这一假设，持续的变化，延髓呼吸神经网络有助于长期促进。颈动脉化学感受器通过封闭动脉注射CO2饱和盐水溶液刺激。在麻醉、注射神经肌肉阻滞剂、切断迷走神经和人工通气的9只成年猫的孤束核（NTS），包括背侧呼吸组（DRG）、Bötzinger腹侧呼吸组（Böt-VRG）和中缝隐核（NRN），同时记录了膈神经传出活动和多达30个单个延髓神经元。105个神经元中有87个（83%）的放电率在诱导长时程易化后发生变化。11个DRG和Böt-VRG假定的运动前吸气神经元中有9个在长时程易化作用下放电频率增加。21个中缝暗神经元中有14个的控制放电率小于4 Hz，其活动长期显著增加。交叉相关图分析表明，长时程易化的神经元对的有效连接发生了变化。联合刺激周时间直方图和模式检测方法与“重力”分析也检测到与长期促进相关的短时间尺度的变化。结果表明，放电率和同步性的VRG和DRG前运动神经元和改变有效的连接之间的其他功能先行元件的延髓呼吸网络的变化有助于长期促进的表达。
Long-term facilitation is a respiratory memory expressed as an increase in motor output lasting more than an hour. This change is induced by repeated hypoxia, stimulation of carotid chemoreceptors, or electrical stimulation of the carotid sinus nerve or brainstem mid-line. The present work addressed the hypothesis that persistent changes in medullary respiratory neural networks contribute to long-term facilitation. Carotid chemoreceptors were stimulated by close arterial injection of CO2-saturated saline solution. Phrenic nerve efferent activity and up to 30 single medullary neurones were recorded simultaneously in nucleus tractus solitarii (NTS) including the dorsal respiratory group (DRG), Bötzinger-ventral respiratory group (Böt-VRG), and nucleus raphe obscurus of nine adult cats, anaesthetized, injected with a neuromuscular blocking agent, vagotomized and artificially ventilated. The firing rates of 87 of 105 neurones (83 %) changed following induction of long-term facilitation. Nine of eleven DRG and Böt-VRG putative premotor inspiratory neurones had increased firing rates with long-term facilitation. Fourteen of twenty-one raphe obscurus neurones with control firing rates less than 4 Hz had significant long-term increases in activity. Cross-correlogram analysis suggested that there were changes in effective connectivity of neuron pairs with long-term facilitation. Joint peristimulus time histograms and pattern detection methods used with ‘gravity’ analysis also detected changes in short time scale correlations associated with long-term facilitation. The results suggest that changes in firing rates and synchrony of VRG and DRG premotor neurones and altered effective connectivity among other functionally antecedent elements of the medullary respiratory network contribute to the expression of long-term facilitation.