Neural mechanisms generating respiratory pattern in mammalian brain stem-spinal cord in vitro. I. Spatiotemporal patterns of motor and medullary neuron activity.
Neural mechanisms generating respiratory pattern in mammalian brain stem-spinal cord in vitro. I. Spatiotemporal patterns of motor and medullary neuron activity.
复制标题
体外哺乳动物脑干脊髓中产生呼吸模式的神经机制。
DOI：
10.1152/jn.1990.64.4.1149
复制
发表时间：
1990
影响因子：
2.5
通讯作者：
Feldman,JL
中科院分区：
文献类型：
--
作者：
Smith,JC;Greer,JJ;Liu,GS;Feldman,JL
1.在体外新生大鼠脑干脊髓制备的呼吸运动模式生成系统的神经元的活动的空间和时间模式的分析。分析了脊髓和颅运动神经元以及延髓呼吸神经元的脉冲放电模式。运动神经元放电的模式，其特征在于在人口水平上的运动神经放电记录和单细胞水平上的细胞内记录。将这些模式与新生大鼠和成年哺乳动物体内产生的模式进行比较，以建立体外和体内状态之间的对应关系。2.体外系统在呼吸周期的吸气（I）和呼气（E）阶段产生了复杂的脊髓和颅运动神经元活动的时空模式。呼吸周期由三个不同的阶段的神经元活动（I，早期E，和晚期E阶段）类似的时间组织的周期在完整的哺乳动物。I期运动神经元的锋电位放电模式由快速峰值-缓慢递减的放电包络组成，在25-50 ms（约20-40 Hz）的时间尺度上具有高度同步性。在与体外状态相当的条件下，在新生儿体内产生了类似的模式（即，从机械感觉传入输入分离的神经系统）。然而，I相运动神经元放电模式和周期相持续时间不同于那些完整的新生儿或成人系统在体内的特点。这种差异主要是由于去除迷走神经机械感觉传入输入。3.在体外脊髓运动神经元的突触驱动电位在I期由一个快速峰值缓慢递减的电位包络的形状相似的尖峰频率直方图的单个运动神经元和运动神经元群体放电的包络。驱动电位具有显著的高频振幅波动叠加在较慢的驱动电位包络上，该包络与运动神经元动作电位的产生在时间上相关。这些快速膜电位振荡的主要频率成分（20-35 Hz）与运动神经元群体放电中振幅波动的频率成分相似。一类具有I相放电的髓神经元也表现出快速峰值缓慢递减的脉冲放电模式和具有类似高频成分的突触驱动电位。（400字处删节）
1. An analysis of the spatial and temporal patterns of activity of neurons of the respiratory motor-pattern generation system in an in vitro neonatal rat brain stem-spinal cord preparation is presented. Impulse discharge patterns of spinal and cranial moto-neurons as well as respiratory neurons in the medulla were analyzed. Patterns of motoneuronal discharge were characterized at the population level from recordings of motor-nerve discharge and at the single-cell level from intracellular recordings. These patterns were compared to patterns generated in the neonatal rat and adult mammal in vivo to establish the correspondence between in vitro and in vivo states. 2. The in vitro system generated a complex spatiotemporal pattern of spinal and cranial motoneuron activity during inspiratory (I) and expiratory (E) phases of the respiratory cycle. The respiratory cycle consisted of three distinct phases of neuronal activity (I, early E, and late E phase) similar to the temporal organization of the cycle in the intact mammal. The spike discharge pattern of motoneurons during the I phase consisted of a rapidly peaking-slowly decrementing discharge envelope with a high degree of synchronization on a time scale of 25-50 ms (approximately 20-40 Hz). A similar pattern was generated in the neonate in vivo under conditions comparable with the in vitro state (i.e., nervous system isolated from mechanosensory afferent inputs). However, the I-phase-motoneuron discharge pattern and cycle-phase durations differed from those characteristic of the intact neonatal or adult systems in vivo. This difference could be accounted for primarily by removal of vagal mechanosensory afferent inputs. 3. The synaptic drive potentials of spinal motoneurons during the I phase in vitro consisted of a rapidly peaking-slowly decrementing potential envelope similar in shape to the spike-frequency histogram of single motoneurons and the envelope of the motoneuron-population discharge. The drive potentials had prominent high-frequency amplitude fluctuations superimposed on the slower drive-potential envelope that were temporally correlated with the generation of motoneuron action potentials. The dominant frequency components of these fast-membrane-potential oscillations (20-35 Hz) were similar to the frequency components of the amplitude fluctuations in the motoneuron-population discharge. One class of medullary neurons with I-phase discharge also exhibited a rapidly peaking-slowly decrementing pattern of impulse discharge and synaptic drive potential with similar high-frequency components.(ABSTRACT TRUNCATED AT 400 WORDS)