Rapid report: the reliability of excitatory synaptic transmission in slices of rat visual cortex in vitro is temperature dependent.
Rapid report: the reliability of excitatory synaptic transmission in slices of rat visual cortex in vitro is temperature dependent.
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发表时间：
1998
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通讯作者：
N. Hardingham;A. Larkman
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作者：
N. Hardingham;A. Larkman
1.在视觉控制下，用全细胞电压记录技术研究了体外培养的大鼠视皮层脑片2/3层锥体神经元之间共12个突触联系。这些联系的强度差异很大，在23℃时，由此产生的兴奋性突触后电位(EPSP)的平均峰值幅度在大约40微V到2 mV之间。较小的平均幅度包括相当大比例的明显传输失败。2.在13至36摄氏度的温度范围内检查了这些EPSP的性能。所有的连接都变得更可靠，因为它们显示出较少的明显传输故障，并且在较高的温度下表现出较小的试验到试验的可变性。这些变化似乎主要是由于每个突触前动作电位释放的平均递质量子数的增加。3.在36摄氏度时，大多数连接都相对可靠，平均失败率仅为16%。在此温度下，五个连接几乎没有出现故障(1%或更少)。4.我们得出结论，量子递质的释放在这些突触上是温度依赖的，在室温下进行的实验可能会导致对中枢兴奋性突触传递的不可靠性的夸大印象。
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 microV 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.