IONIC MECHANISMS CONTROLLING BEHAVIORAL RESPONSES OF PARAMECIUM TO MECHANICAL STIMULATION
IONIC MECHANISMS CONTROLLING BEHAVIORAL RESPONSES OF PARAMECIUM TO MECHANICAL STIMULATION
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DOI：
10.1126/science.164.3882.963
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发表时间：
1969-01-01
期刊：
影响因子：
56.9
通讯作者：
ECKERT, R
中科院分区：
文献类型：
--
作者：
NAITOH, Y;ECKERT, R
施加在草履虫前部的机械刺激会导致膜对钙的渗透性短暂增加。这允许钙电流流入细胞，导致膜电位接近钙的平衡水平。瞬态去极化的结果引起了纤毛拍方向的反转。当生物自由游动时，这被看作是詹宁斯“回避反应”的反向运动。相反，施加于后部的机械刺激会增加钾离子的渗透性，从而产生向外的钾电流。由此产生的超极化导致睫状体在法向搏动频率增加。在自由游动的标本中，这被看作是向前运动速度的增加。
A mechanical stimulus applied to the anterior part ofParameciumcauses a transient increase in membrane permeability to calcium. This permits a calcium current to flow into the cell, causing the membrane potential to approach the equilibrium level for calcium. The transient depolarization which results elicits a reversal in the direction of ciliary beat. When the organisms are free-swimming this is seen as the reversed locomotion of Jennings' "avoiding reaction." In contrast, a mechanical stimulus applied to the posterior part results in increased permeability to potassium ions, and hence an outward potassium current. The hyperpolarization which results causes an increase in the frequency of ciliary beat in the normal direction. In free-swimming specimens this is seen as an increase in the velocity of forward locomotion.