DISCHARGE PROPERTIES OF DORSAL MEDULLARY INSPIRATORY NEURONS - RELATION TO PULMONARY AFFERENT AND PHRENIC EFFERENT DISCHARGE
DISCHARGE PROPERTIES OF DORSAL MEDULLARY INSPIRATORY NEURONS - RELATION TO PULMONARY AFFERENT AND PHRENIC EFFERENT DISCHARGE
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DOI：
10.1152/jn.1984.51.4.753
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发表时间：
1984-01-01
影响因子：
2.5
通讯作者：
FELDMAN, JL
中科院分区：
文献类型：
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作者：
COHEN, MI;FELDMAN, JL
在用循环触发泵系统通气的去大脑瘫痪猫中，该系统在中枢吸气 (I) 阶段（由传出膈放电表示）提供充气，在髓质孤束腹外侧核 (vINTS) 区域记录了 90 个具有吸气调节放电的神经元的活动。其中，82 个具有中心起源的 I 模式（69 个递增，13 个递减），8 个是泵神经元。通过应用充气测试将神经元分为功能类型，主要测试是抑制通常在中央 I 阶段传递的充气。该操作消除了相位性肺传入输入并导致 I 相延长。神经元的反应是异质的，并被分类为：通货膨胀兴奋（通货膨胀（+）），通货膨胀无显着影响（通货膨胀（0）），通货膨胀抑制（通货膨胀（-））。在呼气 (E) 阶段施加充气很少会产生中枢 I 神经元的兴奋。由膨胀激发的 I 神经元对应于 I-.beta。早期研究的神经元。根据其放电起始时间相对于膈起始的多模态分布，将其分为早发型或迟发型。膨胀 (0) 和膨胀 (.sbd.) 神经元，对应于 I-.alpha。神经元几乎都是早期发病的。泵神经元可以通过 E 期间传递的充气效应将泵神经元与充气 (+) I 神经元区分开来：前者在 E 期间和 I 期间受到充气的同等兴奋，而后者在 E 期间不被充气兴奋或受到最小程度的兴奋。泵神经元有肺传入输入，但没有来自中枢 I 模式发生器的输入，而充气 (+) I 神经元有两种输入。在 I（吸气早期和呼气-吸气）期间放电减少的神经元因充气而受到抑制。计算短时间尺度（ms）上单位放电与整个膈（对侧和同侧）活动的互相关直方图（CCH）；其中大多数具有高频振荡，平均周期为 14.6 .+-。 3.6（标准差）毫秒。分析不同神经元组的 CCHS 的相关强度作为主相关峰的偏侧性和滞后的函数。膨胀（O）和膨胀（+）神经元组和相关特性表明这些神经元单突触激发膈运动神经元。讨论了不同类型神经元的可能功能，包括肺传入输入的处理、I 相的终止以及输入到膈运动神经元的传输。
In decerebrate paralyzed cats ventilated with a cycle-triggered pump system that delivered inflation during the central inspiratory (I) phase (indicated by efferent phrenic discharge), activity of 90 neurons with inspiratory-modulated discharge was recorded in the region of the ventrolateral nucleus of tractus solitarius (vINTS) in the medulla. Of these, 82 had centrally originating I patterns (69 augmenting, 13 decrementing), and 8 were pump neurons. The neurons were classified into functional types by the application of inflation tests, the main test being withholding of the inflation usually delivered during the central I phase. This maneuver eliminated phasic pulmonary afferent input and produced lengthening of the I phase. The neurons'' responses were heterogeneous, and were classified as: excitation by inflation (inflation(+)), no significant effect of inflation (inflation(0)), and depression by inflation (inflation(-)). Application of inflation during the expiratory (E) phase only rarely produced excitation of central I neurons. The I neurons excited by inflation correspond to the I-.beta. neurons of earlier studies. On the basis of the multimodal distribution of their discharge onset times relative to phrenic onset, they were classified as early onset or late onset. The inflation (0) and inflation(.sbd.) neurons, which correspond to the I-.alpha. neurons, almost exclusively had early onsets. The pump neurons could be distinguished from the inflation(+) I neurons by the effects of inflations delivered during E: the former were equally excited by inflations during E and during I, while the latter were not excited or were minimally excited by inflation during E. The pump neurons had lung afferent inputs but no inputs from the central I pattern generator, while the inflation (+) I neurons had both kinds of input. The neurons having decrementing discharge during I (early inspiratory and expiratory-inspiratory) were depressed by inflation. Cross-correlation histograms (CCH) of unit firing versus whole phrenic (contralateral and ipsilateral) activity on a short time scale (ms) were computed; the majority of these had high-frequency oscillations, with mean period of 14.6 .+-. 3.6 (SD) ms. The CCHS for the different groups of neurons were analyzed with respect to strength of correlation as a function of laterality and lag of the main correlation peak. Both the inflation(O) and inflation(+) neuronal groups and correlation properties suggesting that these neurons monosynaptically excite phrenic motoneurons. The possible functions of the different types of neuron are discussed with respect to processing of pulmonary afferent inputs, termination of the I phase and transmission of inputs to phrenic motoneurons.