体外苍白球神经元的电生理学

Electrophysiology of globus pallidus neurons in vitro.

作者信息

Nambu A, Llinaś R

机构信息

Department of Physiology and Biophysics, New York University Medical Center, New York 10016.

出版信息

J Neurophysiol. 1994 Sep;72(3):1127-39. doi: 10.1152/jn.1994.72.3.1127.

DOI:10.1152/jn.1994.72.3.1127

PMID:7807199

Abstract

We investigated the electrical properties of globus pallidus neurons intracellularly using brain slices from adult guinea pigs. Three types of neurons were identified according to their intrinsic electrophysiological properties. 2. Type I neurons (59%) were silent at the resting membrane level (-65 +/- 10 mV, mean +/- SD) and generated a burst of spikes, with strong accommodation, to depolarizing current injection. Calcium-dependent low-frequency (1-8 Hz) membrane oscillations were often elicited by membrane depolarization (-53 +/- 8 mV). A low-threshold calcium conductance and an A-current were also identified. The mean input resistance of this neuronal type was 70 +/- 22 M omega. 3. Type II neurons (37%) fired spontaneously at the resting membrane level (-59 +/- 9 mV). Their repetitive firing (< or = 200 Hz) was very sensitive to the amplitude of injected current and showed weak accommodation. Sodium-dependent high-frequency (20-100 Hz) subthreshold membrane oscillations were often elicited by membrane depolarization. This neuronal type demonstrated a low-threshold calcium spike and had the highest input resistance (134 +/- 62 M omega) of the three neuron types. 4. Type III neurons (4%) did not fire spontaneously at the resting membrane level (-73 +/- 5 mV). Their action potentials were characterized by a long duration (2.3 +/- 0.6 ms). Repetitive firing elicited by depolarizing current injection showed weak or no accommodation. This neuronal type had an A-current and showed the lowest input resistance (52 +/- 35 M omega) of the three neuron types. 5. Stimulation of the caudoputamen evoked inhibitory postsynaptic potentials (IPSPs) in Type I and II neurons. In Type II neurons the IPSPs were usually followed by rebound firing. Excitatory postsynaptic potentials and antidromic responses were also elicited in some Type I and II neurons. The estimated conduction velocity of the striopallidal projection was < 1 m/s (Type I neurons, 0.49 +/- 0.37 m/s; Type II neurons, 0.33 +/- 0.13 m/s).

摘要

我们使用成年豚鼠的脑片，对苍白球神经元的电特性进行了细胞内研究。根据其内在电生理特性，鉴定出三种类型的神经元。2. I型神经元（59%）在静息膜电位水平（-65±10 mV，平均值±标准差）时呈静息状态，对去极化电流注入产生一串动作电位，且有强烈的适应性。膜去极化（-53±8 mV）常引发钙依赖性低频（1 - 8 Hz）膜振荡。还鉴定出一种低阈值钙电导和一种A电流。这种神经元类型的平均输入电阻为70±22 MΩ。3. II型神经元（37%）在静息膜电位水平（-59±9 mV）时自发放电。它们的重复放电（≤200 Hz）对注入电流的幅度非常敏感，且适应性较弱。膜去极化常引发钠依赖性高频（20 - 100 Hz）阈下膜振荡。这种神经元类型表现出低阈值钙峰电位，并且在三种神经元类型中具有最高的输入电阻（134±62 MΩ）。4. III型神经元（4%）在静息膜电位水平（-73±5 mV）时不自发放电。它们的动作电位具有持续时间长（2.3±0.6 ms）的特点。去极化电流注入引发的重复放电表现出较弱的适应性或无适应性。这种神经元类型有A电流，并且在三种神经元类型中具有最低的输入电阻（52±35 MΩ）。5. 刺激尾壳核在I型和II型神经元中诱发抑制性突触后电位（IPSPs）。在II型神经元中，IPSPs之后通常会出现反弹放电。在一些I型和II型神经元中也诱发了兴奋性突触后电位和逆向反应。纹状体苍白球投射的估计传导速度<1 m/s（I型神经元，0.49±0.37 m/s；II型神经元，0.33±0.13 m/s）。