The reliability of excitatory synaptic transmission in slices of rat visual cortex in vitro is temperature dependent
The reliability of excitatory synaptic transmission in slices of rat visual cortex in vitro is temperature dependent
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DOI：
10.1111/j.1469-7793.1998.249bu.x
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发表时间：
1998-02-15
影响因子：
5.5
通讯作者：
Larkman, AU
中科院分区：
文献类型：
--
作者：
Hardingham, NR;Larkman, AU
1.在视觉控制条件下，采用全细胞电压记录法研究了体外培养的大鼠视皮层2/3层锥体神经元之间的共12个突触连接。连接的强度变化很大，在23 ℃时，产生的兴奋性突触后电位（EPSP）的平均峰值幅度在约40 μ V和2 mV之间。较小的平均振幅包括相当大比例的明显传输失败。这些EPSP的性能在13至36摄氏度的温度范围内进行了检查。所有的连接都变得更加可靠，因为它们显示出更少的明显传输故障，并且在较高的温度下显示出更少的试验间变异性。这些变化似乎主要是由于每个突触前动作电位释放的递质量子的平均数量增加。在36摄氏度时，大多数连接相对可靠，平均故障率仅为16%。在此温度下，五个连接几乎没有出现故障（1%或更少）。我们的结论是，量子发射器的释放是温度依赖于这些突触，在室温下进行的实验可能会导致一个夸张的印象，在中央兴奋性突触传输的不可靠性。
1. A total of twelve synaptic connections between pairs of pyramidal neurones in layer 2/3 of slices of rat visual cortex maintained in vitro was investigated using whole-cell voltage recordings under visual control. The connections varied widely in strength, with the mean peak amplitudes of the resulting excitatory postsynaptic potentials (EPSPs) ranging between approximately 40 mu V and 2 mV at 23 degrees C. The smaller mean amplitudes included a substantial proportion of apparent failures of transmission.2. The properties of these EPSPs were examined over a range of temperatures between 13 and 36 degrees C. All the connections became more reliable, in that they showed fewer apparent failures of transmission, and showed less trial-to-trial variability at the higher temperatures. These changes appeared to be due primarily to an increase in the mean number of transmitter quanta released per presynaptic action potential.3. At 36 degrees C most connections were relatively reliable, with a mean failure rate of only 16%. Five connections showed virtually no failures (1% or fewer) at this temperature.4. We conclude that quantal transmitter release is temperature dependent at these synapses, and that experiments performed at room temperature could lead to an exaggerated impression of the unreliability of transmission at central excitatory synapses.