ELECTROPHYSIOLOGICAL PROPERTIES OF GUINEA-PIG THALAMIC NEURONS - AN INVITRO STUDY
ELECTROPHYSIOLOGICAL PROPERTIES OF GUINEA-PIG THALAMIC NEURONS - AN INVITRO STUDY
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DOI：
10.1113/jphysiol.1984.sp015153
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发表时间：
1984-01-01
影响因子：
5.5
通讯作者：
LLINAS, R
中科院分区：
文献类型：
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作者：
JAHNSEN, H;LLINAS, R
使用体外切片制备研究了豚鼠丘脑神经元的电响应特性。细胞内共记录了650个细胞，包括丘脑的所有区域;其中229个符合我们的记录稳定性标准，并用作本报告的数据库。详细分析的34个代表性神经元的静息膜电位为-64 +/-5 mV（平均值+/-S.D.），输入电阻42 +/-18 M Ω，动作电位振幅80 +/-7 mV。辣根过氧化物酶和荧光黄细胞内染色显示，记录的细胞具有不同的形态。在某些情况下，它们的轴突轨迹将它们描述为丘脑皮质中继细胞。观察到两种主要类型的神经元放电。从膜电位负到-60 mV，逆向或顺向和直接激活产生单次尖峰脉冲，包括低阈值尖峰（l.t.s.）低振幅和一系列快速叠加的尖峰如果神经元从更正的膜电位激活，则观察到紧张性重复放电;除了两个满足稳定性标准的细胞外，这是所有细胞中的恒定发现。LT反应在膜电位为正至-55 mV时完全失活。当膜从该水平超极化时，l.t.s.增加并在负电位至-70 mV时完全发育。这种增加是由于产生这种反应的离子电导失活所致。激活后，l.t.s.显示约170 ms的不应期。是一个电压和时间依赖性过程;在一步超极化至最大l.t.s.后完全失活。膜去极化正向至-55 mV产生突然持续的去极化“平台电位”，能够支持重复放电（每个动作电位之后是显著的后超极化，a. h. p.）。a. h. p.和平台电位控制的电压轨迹在interspike间隔，并与快速尖峰，构成一个功能状态，丘脑神经元显示振荡特性。通过施加长持续时间（2s）的方波电流脉冲，获得不同初始水平膜电位的频率-电流（f-I）图。从静息膜电位和超极化水平，由于l.t.s.的存在，观察到相当定型的起始放电率。（400字处截断摘要）
The electroresponsive properties of guinea‐pig thalamic neurones were studied using an in vitro slice preparation. A total of 650 cells were recorded intracellularly comprising all regions of the thalamus; of these 229 fulfilled our criterion for recording stability and were used as the data base for this report. The resting membrane potential for thirty‐four representative neurones which were analysed in detail was ‐64 +/‐ 5 mV (mean +/‐ S.D.), input resistance 42 +/‐ 18 M omega, and action potential amplitude 80 +/‐ 7 mV. Intracellular staining with horseradish peroxidase and Lucifer Yellow revealed that the recorded cells had different morphology. In some their axonal trajectory characterized them as thalamo‐cortical relay cells. Two main types of neuronal firing were observed. From a membrane potential negative to ‐60 mV, anti‐ or orthodromic and direct activation generated a single burst of spikes, consisting of a low‐threshold spike (l.t.s.) of low amplitude and a set of fast superimposed spikes. Tonic repetitive firing was observed if the neurones were activated from a more positive membrane potential; this was a constant finding in all but two of the cells which fulfilled the stability criteria. The l.t.s. response was totally inactivated at membrane potentials positive to ‐55 mV. As the membrane was hyperpolarized from this level the amplitude of the l.t.s. increased and became fully developed at potentials negative to ‐70 mV. This increase is due to a de‐inactivation of the ionic conductance generating this response. After activation the l.t.s. showed refractoriness for approximately 170 ms. Deinactivation of l.t.s. is a voltage‐ and time‐dependent process; full de‐inactivation after a step hyperpolarization to maximal l.t.s. amplitude (‐75 to ‐80 mV) requires 150‐180 ms. Membrane depolarization positive to ‐55 mV generated sudden sustained depolarizing 'plateau potentials', capable of supporting repetitive firing (each action potential being followed by a marked after‐hyperpolarization, a.h.p.). The a.h.p. and the plateau potential controlled the voltage trajectory during the interspike interval and, with the fast spike, constitute a functional state where the thalamic neurone displayed oscillatory properties. Frequency‐current (f‐I) plots from different initial levels of membrane potential were obtained by the application of square current pulses of long duration (2s). From resting membrane potential and from hyperpolarized levels a rather stereotyped onset firing rate was observed due to the presence of the l.t.s.(ABSTRACT TRUNCATED AT 400 WORDS)