Núñez A, Barrenechea C, Avendaño C
Departamento de Morfologia, Facultad de Medicina, Universidad Autónoma de Madrid, Spain.
Somatosens Mot Res. 1994;11(1):89-98. doi: 10.3109/08990229409028861.
Spontaneous activity and responses to sensory stimulation in ventrobasal (VB) thalamic neurons were studied in barbiturate-anesthetized rats through intracellular recordings. The recordings were carried out with micropipettes filled with K acetate KCl plus horseradish peroxidase (HRP), our KCl plus biocytin. Two types of spontaneous depolarizing events were observed: fast potentials (FPs), characterized by a low amplitude (5.3 +/- 1.8 mV [mean and standard deviation]), a fast rising slope (1.15 +/- 0.19 msec), and a short duration (8.47 +/- 0.89 msec); and slow potentials (SPs), characterized by a larger and more variable amplitude (9.1 +/- 5.6 mV) and a longer duration (62.5 +/- 27.2 msec), with a slower rising slope (26.2 +/- 6.4 msec). The potential changes elicited by sensory stimuli delivered manually were similar to those elicited by electronically gated short air jets to the receptive fields. FPs were evoked by sensory stimulation in 62.7% of the recorded neurons, and SPs in the remaining 37.3%. Both types of events could occur spontaneously in the same neuron, but only one of them was triggered by stimulation of the receptive field. Five neurons that were successfully stained with either HRP or biocytin were studied in detail. All were medium-sized stellate cells, with spine-like appendages sparsely distributed along slender radiating dendrites. The axons took a rostrolateral course across the VB, and all but one left one or two thin collaterals in the reticular thalamic nucleus. No overt morphological differences were observed between VB neurons that responded with FPS or SPs to sensory stimulation.
通过细胞内记录，在巴比妥类麻醉大鼠中研究了腹侧基底（VB）丘脑神经元的自发活动和对感觉刺激的反应。记录使用填充有醋酸钾、氯化钾加辣根过氧化物酶（HRP）或氯化钾加生物素的微电极进行。观察到两种类型的自发去极化事件：快电位（FPs），其特征为低幅度（5.3±1.8 mV [平均值和标准差]）、快速上升斜率（1.15±0.19毫秒）和短持续时间（8.47±0.89毫秒）；以及慢电位（SPs），其特征为幅度更大且变化更大（9.1±5.6 mV）和持续时间更长（62.5±27.2毫秒），上升斜率较慢（26.2±6.4毫秒）。手动施加感觉刺激引起的电位变化与通过电子门控短空气喷射施加到感受野引起的电位变化相似。62.7%的记录神经元中感觉刺激诱发了FPs，其余37.3%诱发了SPs。两种类型的事件都可以在同一神经元中自发发生，但只有其中一种是由感受野刺激触发的。对5个成功用HRP或生物素染色的神经元进行了详细研究。所有神经元均为中等大小的星状细胞，沿着细长的放射状树突稀疏分布着棘状附属物。轴突呈 rostrolateral 走向穿过 VB，除一个外，所有轴突在丘脑网状核中留下一两个细侧支。对感觉刺激以FPS或SPs做出反应的VB神经元之间未观察到明显的形态差异。
