FUNCTIONAL CHARACTERISTICS OF UNMYELINATED FIBERS IN HIPPOCAMPAL CORTEX
FUNCTIONAL CHARACTERISTICS OF UNMYELINATED FIBERS IN HIPPOCAMPAL CORTEX
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DOI：
10.1016/0006-8993(78)90431-6
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发表时间：
1978-01-01
期刊：
影响因子：
2.9
通讯作者：
WIGSTROM, H
中科院分区：
文献类型：
--
作者：
ANDERSEN, P;SILFVENIUS, H;WIGSTROM, H
取自乙醚麻醉的豚鼠海马片(350微米厚)，用钨微电极产生的小电流脉冲激活皮质内传入纤维。细胞外电位记录来自树突层中激活纤维的区域；细胞内记录来自CA1锥体细胞的胞体。当从与刺激阴极相同的水平进行记录时，细胞外电位由双相偏转和随后更大的负波和叠加的群峰组成。负波对应于细胞内记录的兴奋性突触后电位，称为细胞外EPSP；最初的双相偏转没有细胞内对应的EPSP。初始双相偏转与细胞内和细胞外EPSP的大小呈线性关系。去除浴液中的Ca~(2+)不会改变突触后的活动。双相偏转沿平行于锥体层的纤维以0.3m/S的速度传播，可跟随300 Hz的短脉冲刺激。绝对不应期为2.0ms。最初的双相偏转被解释为大部分无髓传入纤维对CA1神经元的复合动作电位。
In transverse hippocampal slices (350 .mu.m thick), taken from guinea pigs initially anesthetized with ether, intracortical afferent fibers were activated by small current pulses delivered through tungsten microelectrodes. Extracellular potentials were recorded from the zone of activated fibers in dendritic layers; intracellular recordings were made from the soma of CAl pyramidal cells. When a recording was made from the same level as the stimulating cathode, the extracellular potential consisted of a diphasic deflection followed by a larger negative wave with a superimposed population spike. The negative wave corresponded to an intracellularly recorded EPSP [excitatory postsynaptic potential] and is called an extracellular EPSP; the initial diphasic deflection had no intracellular counterpart. The initial diphasic deflection was linearly related to the size of the intracellular and extracellular EPSP. It was not changed by removal of Ca2+ from the bathing fluid; all postsynaptic activity disappeared. The diphasic deflection was propagated along fibers lying parallel to the pyramidal layer with a velocity of 0.3 m/s. It could follow short bursts of stimulation at 300 Hz. The absolute refractory period was 2.0 ms. The initial diphasic deflection is interpreted as the compound action potential of the largely unmyelinated afferent fibers to the CAl neurons.