Contribution of individual spikes in burst-induced long-term synaptic modification
Contribution of individual spikes in burst-induced long-term synaptic modification
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DOI：
10.1152/jn.00910.2005
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发表时间：
2006-03-01
影响因子：
2.5
通讯作者：
Dan, Y
中科院分区：
文献类型：
--
作者：
Froemke, RC;Tsay, IA;Dan, Y
长时程突触修饰依赖于单个突触前和突触后尖峰的相对时间，但多峰爆发效应的规则仍有待充分理解。特别是，一些研究表明，突触修饰的尖峰时间依赖性随着高频爆发而分解。在这项研究中，我们的特点的影响，前和突触后爆发的长期修改层2/3突触在年轻大鼠的视觉皮层切片。我们发现，虽然配对诱导的突触修饰取决于突发频率，这种依赖性可以解释在个人的突触前和突触后尖峰的时间。在每一个突发中的后期尖峰在突触修饰中不太有效，但是尖峰效力在突触前和突触后突发中受到不同的调节。在突触前，尖峰效应逐渐减弱，与短期突触抑制平行。在突触后，尖峰功效受到较小程度的抑制，并且它取决于突触后钾通道的激活。多个尖峰之间的这种时间依赖性相互作用可以解释由各种尖峰序列诱导的突触修饰，包括由突触前爆发之前的突触后爆发诱导的从抑制到增强的频率依赖性转变。
Longterm synaptic modification depends on the relative timing of individual pre- and postsynaptic spikes, but the rules governing the effects of multispike bursts remain to be fully understood. In particular, some studies suggest that the spike timing dependence of synaptic modification breaks down with high-frequency bursts. In this study, we characterized the effects of pre- and postsynaptic bursts on long-term modification of layer 2/3 synapses in visual cortical slices from young rats. We found that, while pairing-induced synaptic modification depends on the burst frequency, this dependence can be explained in terms of the timing of individual pre- and postsynaptic spikes. Later spikes in each burst are less effective in synaptic modification, but spike efficacy is regulated differently in pre- and postsynaptic bursts. Presynaptically, spike efficacy is progressively weakened, in parallel with short-term synaptic depression. Postsynaptically, spike efficacy is suppressed to a lesser extent, and it depends on postsynaptic potassium channel activation. Such timing-dependent interaction among multiple spikes can account for synaptic modifications induced by a variety of spike trains, including the frequency-dependent transition from depression to potentiation induced by a postsynaptic burst preceding a presynaptic burst.