LONG-TERM SYNAPTIC ENHANCEMENT AND SHORT-TERM POTENTIATION IN RAT FASCIA DENTATA ACT THROUGH DIFFERENT MECHANISMS
LONG-TERM SYNAPTIC ENHANCEMENT AND SHORT-TERM POTENTIATION IN RAT FASCIA DENTATA ACT THROUGH DIFFERENT MECHANISMS
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DOI：
10.1113/jphysiol.1982.sp014110
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发表时间：
1982-01-01
影响因子：
5.5
通讯作者：
MCNAUGHTON, BL
中科院分区：
文献类型：
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作者：
MCNAUGHTON, BL
研究了戊巴比酮钠麻醉下大鼠牙筋膜穿孔通路突触功能激活后变化的组成过程。由于刺激强度低，只激活了相对较少的穿孔路径纤维，重复刺激导致的效果与在类似条件下观察到的神经肌肉突触具有非常相似的特征。成对的冲击导致了短暂的（.apprx）。100毫秒)的促进叠加在一个凹陷上，可能是由于可用的发射机耗尽，其恢复较慢(.apprx。4 s)。125-250 Hz的短时间刺激会导致突触强度的持续增加，并在双指数时间过程中衰减到控制水平。2个指数分量在神经肌肉突触表现为增强和增强，时间常数为33度。C .大约；5和。apprx。分别是90年代。相同频率和持续时间的高强度刺激训练导致突触强度增强，持续时间为100 ~ 30 min。配对冲击损耗效应与低强度刺激训练后出现的增强和增强量成正比。在高强度刺激训练后，成对的冲击损耗效应增加了相同的量，并在与低强度刺激训练相同的时间过程中恢复，尽管突触反应仍然显著增强。增强和增强是由于发射器释放的可能性增加；长期增强是通过其他一些尚未确定的机制起作用的。在高强度刺激后，所有过程都被激活。
The component processes contributing to post-activation change in synaptic efficacy in the perforant pathway to the fascia dentata were studied in rats under sodium pentobarbitone anesthesia. With low stimulus strength, which activated only a relatively small number of perforant path fibers, repetitive stimulation led to effects which had very similar characteristics to those observed at neuromuscular synapses under similar conditions. Paired shocks resulted in a short (.apprx. 100 ms) facilitation superimposed on a depression, possibly due to depletion of available transmitter, which recovered more slowly (.apprx. 4 s). Short trains of stimuli at 125-250 Hz led to a longer lasting increase in synaptic strength which decayed to control levels with a double exponential time course. The 2 exponential components behaved like augmentation and potentiation at neuromuscular synapses, with time constants at 33.degree. C of .apprx. 5 and .apprx. 90 s, respectively. High-intensity stimulus trains of identical frequency and duration led to an enhancement of synaptic strength which lasted > 30 min. The paired shock depletion effect was increased in direct proportion to the amount of augmentation and potentiation present following low-intensity stimulus trains. Following high-intensity trains the paired shock depletion effect was increased by the same amount, an recovered with the same time course as following low-intensity stimulus trains, even though there remained a significant enhancement of the synaptic response. Augmentation and potentiation are due to an increase in the probability of transmitter release; long-term enhancement acts through some other, as yet undetermined, mechanism. Following high-intensity stimulation all processes are activated.