Inhibitory synaptic currents in rat cerebellar Purkinje cells: modulation by postsynaptic depolarization.
Inhibitory synaptic currents in rat cerebellar Purkinje cells: modulation by postsynaptic depolarization.
复制标题
大鼠小脑浦肯野细胞中的抑制性突触电流：突触后去极化的调节。
DOI：
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Alain Marty
中科院分区：
文献类型：
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作者：
Pierre Vincent;C. M. Armstrong;Alain Marty
1.使用密封全细胞记录技术在电压钳位小脑浦肯野细胞中记录突触电流。用CsCl溶液透析细胞，并保持在-60或-70 mV。使用位于分子层中的细胞外移液管刺激抑制性中间神经元（篮状细胞和星状细胞）。浴溶液中包括兴奋性突触能突触的阻断剂。2.在3 - 4 ms的潜伏期后观察到诱发的突触电流。在大多数情况下，突触电流的时间过程可以拟合为双指数曲线，上升时间常数τ on为1 - 3 ms，衰减时间常数τ off为7 - 13 ms。这些电流被荷包牡丹碱阻断。3.当刺激电极上的电压增加时，诱发的突触电流的平均幅度呈不连续的阶跃增加。在每个水平上，在试验中观察到非常显著的振幅波动。4.偶尔观察到与突触前神经元的重复活动相对应的复杂突触电流，特别是在高强度突触前刺激下。这种重复的活动可能导致突触电流持续数秒的爆发。5.在突触后浦肯野细胞的去极化电压序列，诱发的突触电流的幅度首先被抑制，然后增强。抑制是伴随着一个小的，但一致的增加，在tau关闭，并没有改变tau on. When使用小强度突触前刺激，它被发现，失败的概率大大提高。抑制相持续约1分钟，然后让位于增强。增强恢复到对照组，半衰减时间为12.9 +/-0.9 min。本实验结果进一步证实了浦肯野细胞去极化产生的抑制作用主要是突触前的假说。另一方面，持续时间较长的增强作用很可能起源于突触后。小脑浦肯野细胞从位于分子层的两类中间神经元接受抑制性GABA能输入（综述见Palay & Chan‐Palay，1974; Ito，1984）。篮状细胞最接近浦肯野细胞层，并主要将其抑制信号传递给索马和主树突。星状细胞位于更外部，并与浦肯野细胞树突状分支的更远端部分接触。（400字处截断摘要）
1. Synaptic currents were recorded in voltage‐clamped cerebellar Purkinje cells using the tight‐seal whole‐cell recording technique. Cells were dialysed with a CsCl solution and were held at ‐60 or ‐70 mV. Inhibitory interneurones (basket and stellate cells) were stimulated using an extracellular pipette positioned in the molecular layer. Blockers of excitatory glutamatergic synapses were included in the bath solution. 2. Evoked synaptic currents were observed after a latency of 3‐4 ms. The time course of synaptic currents could in most cases be fitted to a biexponential curve, with a rise time constant, tau on, of 1‐3 ms and a decay time constant, tau off, of 7‐13 ms. These currents were blocked by bicuculline. 3. The mean amplitude of evoked synaptic currents increased in discrete steps when the voltage applied to the stimulating pipette was increased. At each level, very prominent fluctuations of the amplitude were observed among trials. 4. Complex synaptic currents corresponding to repetitive activity of the presynaptic interneurone were occasionally observed, particularly with high intensity presynaptic stimulation. This repetitive activity could lead to bursts of synaptic currents lasting for several seconds. 5. Following a depolarizing voltage train in the postsynaptic Purkinje cell, the amplitude of evoked synaptic currents was first inhibited, and then potentiated. The inhibition was accompanied by a small but consistent increase in tau off and by no alteration in tau on. When using small intensity presynaptic stimuli, it was found that the probability of failures was greatly enhanced. The inhibitory phase lasted for about 1 min before giving way to potentiation. The potentiation returned to the control with a time to half‐decay of 12.9 +/‐ 0.9 min. 6. The present results give further evidence to a previously proposed hypothesis that the inhibition produced by Purkinje cell depolarization is mainly presynaptic. The longer lasting potentiation, on the other hand, has most probably a postsynaptic origin. Cerebellar Purkinje cells receive inhibitory GABAergic inputs from two classes of interneurones located in the molecular layer (reviewed in Palay & Chan‐Palay, 1974; Ito, 1984). Basket cells are closest to the Purkinje cell layer and address their inhibitory signal primarily to the soma and to the main dendrites. Stellate cells are more externally located and have contacts with the more distal part of the dendritic arborization of Purkinje cells.(ABSTRACT TRUNCATED AT 400 WORDS)
DOI：
10.1073/pnas.87.7.2662
发表时间：
1990-04-01
影响因子：
11.1
作者：
KONNERTH, A;LLANO, I;ARMSTRONG, CM
通讯作者：
ARMSTRONG, CM
影响因子：
5.5
作者：
LLINAS, R;SUGIMORI, M
通讯作者：
SUGIMORI, M