Long-term potentiation in the hippocampus using depolarizing current pulses as the conditioning stimulus to single volley synaptic potentials
Long-term potentiation in the hippocampus using depolarizing current pulses as the conditioning stimulus to single volley synaptic potentials
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DOI：
10.1523/jneurosci.07-03-00774.1987
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发表时间：
1987-03
期刊：
影响因子：
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通讯作者：
B. Gustafsson;H. Wigstrom;W. Abraham;Yy Huang
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文献类型：
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作者：
B. Gustafsson;H. Wigstrom;W. Abraham;Yy Huang
在制备的海马片的CA1区检查了与长时程增强(LTP)相关特性有关的条件。以低频(0.15-0.1 Hz)单次抽射刺激辐射层或辐射层，细胞内记录到的EPSP与通过记录微电极注入的去极化电流脉冲(50-100毫秒)配对。结果表明，当与足够大的脉冲配对时，这些EPSP被增强。这种增强通常在20-30次配对活动后达到峰值，并可能比适应期持续1小时以上。它是针对配对输入的，被2-氨基-5-磷酸戊酸(APV)阻断，并被先前的同源突触破伤法阻断(反之亦然)。在用印防己毒素(PTX)在浴液中进行的实验中，用2-4nA的电流脉冲增强EPSP，在正常溶液中的值略高。在正常和PTX溶液中，有效电流脉冲产生7-11个尖峰放电(每100毫秒)的重复尖峰放电，在这个范围内，频率越高，潜伏期越大。然而，由于在细胞内QX-314阻断棘波活动后观察到了相似程度的EPSP增强，所以脉冲活动不是主要的条件反射因素。为了出现增强，EPSP必须与电流脉冲一起发生或先于电流脉冲大约100毫秒。当EPSP立即在脉冲之后时，没有观察到增强作用。结果表明，LTP的协作性方面与突触后充分去极化的需要有关。
The conditions responsible for the associative properties of long-term potentiation (LTP) were examined in the CA1 region of the hippocampal slice preparation. Intracellularly recorded EPSPs resulting from single- volley stimulation at low frequency (0.15–0.1 Hz) in the stratum radiatum or oriens were paired with depolarizing current pulses (50–100 msec) injected through the recording microelectrode. It is shown that these EPSPs, when paired with pulses of sufficient magnitude, become potentiated. This potentiation generally reached a peak after 20–30 pairing events and could outlast the conditioning period by more than 1 hr. It was specific to the paired input, was blocked by 2-amino-5- phosphonovalerate (APV) and was largely blocked by prior homosynaptic tetanization (and vice versa). In experiments performed with picrotoxin (PTX) in the bath, EPSPs were potentiated using 2–4 nA current pulses, with somewhat higher values in normal solution. The effective current pulses, in both normal and PTX solution, produced a repetitive spike discharge of 7–11 spikes (per 100 msec), and within this range, higher frequencies were associated with larger potentiations. However, since similar degrees of EPSP potentiation were observed following blockade of spike activity by intracellular QX-314, spike activity was not the primary conditioning factor. For the potentiation to appear, the EPSP had to occur together with the current pulse or precede it by less than about 100 msec. No potentiation was observed when the EPSP immediately succeeded the pulse. The results suggest that the cooperativity aspect of LTP is related to a need for sufficient postsynaptic depolarization.(ABSTRACT TRUNCATED AT 250 WORDS)