Quantal synaptic transmission in phrenic motor nucleus.
Quantal synaptic transmission in phrenic motor nucleus.
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膈运动核中的量子突触传递。
DOI：
10.1152/jn.1992.68.4.1468
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发表时间：
1992
影响因子：
2.5
通讯作者：
Feldman,JL
中科院分区：
文献类型：
--
作者：
Liu,G;Feldman,JL
1.在体外培养的新生大鼠脑干-脊髓标本上，观察了呼吸间神经元和膈运动神经元兴奋性突触传递的量子性质。采用全细胞膜片钳记录技术记录突触电流。2.由于量子检测最重要的因素是量子尺寸与量子标准差的比值，因此对影响量子尺寸与量子标准差之比的因素进行了评估，从而确定了提高这一比值的实验技术。3.在适宜的条件下，我们直接观察到脊髓呼吸神经元自发兴奋性突触后电流(EPSCs)的量子幅度波动。量子电导大小为55-100ps。随着这些EPSC的快速衰变，到达SOMA的单个量子的电荷大约只有15fC(VH=-80 mV)。4.我们还研究了EPSC的微小幅度分布。正如之前报道的那样，这些是偏斜的；然而，观察到了明显的量子间隔。此外，在被测试的三个细胞中，微型EPSC幅度分布中的量子大小与自发EPSC幅度分布中的量子大小相似。5.我们得出结论：哺乳动物脊髓中兴奋性突触传递是量子的，EPSC微小分布的明显偏斜性是多个量子峰值幅度的事件的总和。
1. The quantal nature of excitatory synaptic transmission was studied in respiratory interneurons and phrenic motoneurons of intact neonatal rat brain stem-spinal cord preparations in vitro. Synaptic currents were recorded with whole-cell patch-clamp recording techniques. 2. Because the most important factor for quantal detection is the ratio of quantal size to quantal standard deviation, factors that influence this ratio were evaluated so that experimental techniques that enhance this ratio could be defined. 3. Under favorable conditions, we directly observed quantal amplitude fluctuations in spontaneous excitatory postsynaptic currents (EPSCs) in spinal cord respiratory neurons. The quantal conductance size was 55-100 pS. With fast decay of these EPSCs, the charge reaching the soma for a single quantum is only approximately 15 fC (Vh = -80 mV). 4. We also studied miniature EPSC amplitude distributions. These were skewed, as previously reported; however, distinct quantal intervals were observed. Furthermore, in three cells tested, the quantal size in the miniature EPSC amplitude distribution was similar to the quantal size in the spontaneous EPSC amplitude distribution. 5. We conclude that excitatory synaptic transmission in the mammalian spinal cord is quantal and that the apparent skewness of miniature EPSC distributions results from summation of events with multiple quantal peak amplitudes.