A comparative analysis of coordinated neuronal activity in the thalamic ventrobasal complex of rats and cats.
A comparative analysis of coordinated neuronal activity in the thalamic ventrobasal complex of rats and cats.
复制标题
大鼠和猫丘脑腹基底复合体协调神经元活动的比较分析。
DOI：
10.1016/0006-8993(95)00602-m
复制
发表时间：
1995
期刊：
影响因子：
2.9
通讯作者：
Aaron,GB
中科院分区：
文献类型：
--
作者：
Alloway,KD;Johnson,MJ;Aaron,GB
大鼠和猫丘脑腹底复合体中抑制性神经元的发生率存在显著差异。神经元组成的这种显著差异表明，在皮肤刺激时，这些区域的神经活动的编排应该有相应的差异。为了探索这种可能性，我们对麻醉大鼠和猫的腹后外侧核（VPL）的神经元活动进行了交叉相关分析。在空气喷射刺激整个感受野的多个部位时，用一个或两个电极同时记录了代表毛状皮肤的成对神经元。交叉相关直方图显示相邻神经元之间的相关活动以三种不同的模式发生。在一种被归类为窄单峰的模式中，一个神经元的放电先于另一个神经元的放电，时间间隔很短（<5毫秒）。窄双峰模式的特征是两个神经元放电的时间顺序是可变的，但脉冲间隔总是小于5 ms。在宽单峰模式中，一个神经元的放电与同伴神经元随后的放电在很宽的时间间隔内（约5 ms）相关。在大鼠VPL中，58个神经元对中有三分之二表现出窄单峰反应，近三分之一的神经元对表现出窄双峰反应。只有一对大鼠VPL神经元具有宽单峰协调模式。相比之下，在cat VPL中具有协调反应的61对相邻神经元对中，有一半以窄单峰模式为特征。略多于三分之一的相关神经元对具有窄双峰模式，而其余的（13%）被归类为宽单峰反应。间隔340 ~ 405 μm的成对神经元同步放电，其模式与相邻神经元的窄双峰模式的时间关系相似。在这两个物种中，宽单峰模式具有最强的协调响应。尽管抑制关系没有出现在刺激协调相关的相关直方图中，但对原始峰值序列的交叉相关分析显示，猫VPL神经元表现出宽单峰协调模式的抑制期很短（10-40 ms）。在大鼠VPL中，大多数抑制涉及更长（30-60 ms）的抑制振荡周期，出现在更大的节奏模式中。这些结果表明，在狭窄的时间间隔（<5 ms）内发生的相关模式代表了相邻丘脑皮质中继神经元之间活动的协调。相比之下，宽单峰模式似乎代表丘脑皮质中继细胞和内在抑制神经元之间的协调活动。
There are substantial differences in the incidence of inhibitory neurons in the ventrobasal complex of rat and cat thalamus. This marked dissimilarity in neuronal composition suggests that there should be corresponding differences in the orchestration of neural activity in these regions during cutaneous stimulation. To explore this possibility, we conducted a cross-correlation analysis of neuronal activity in the ventroposterolateral (VPL) nucleus of anesthetized rats and cats. Pairs of neurons representing hairy skin were recorded simultaneously with one or two electrodes during air jet stimulation of multiple sites throughout the receptive fields. Cross-correlation histograms indicated that correlated activity among adjacent neurons occurred in three distinct patterns. In one pattern, classified as narrow-unimodal, the discharge of one neuron preceded a discharge in the partner neuron over a narrow interval of time (<5 ms). Narrow-bimodal patterns were characterized by responses in which the temporal order of discharges from the two neurons was variable, but the interspike intervals were always <5 ms. In wide-unimodal patterns, the discharge of one neuron was correlated with subsequent discharges in the partner neuron over a wide interval of time (>5 ms). In rat VPL, two-thirds of the 58 neuron pairs showing correlated responses were characterized by narrow-unimodal responses and nearly one-third of the neuron pairs displayed narrow-bimodal patterns. Only one pair of rat VPL neurons were characterized by a wide-unimodal pattern of coordination. By comparison, half of the 61 adjacent neuron pairs with coordinated responses in cat VPL were characterized by narrow-unimodal patterns. Slightly more than one-third of the correlated neuron pairs had narrow-bimodal patterns, while the remainder (13%) were classified as wide-unimodal responses. Pairs of neurons separated by 340–405 μm discharged synchronously in a pattern that was similar to the temporal relationship expressed in the narrow-bimodal patterns found among adjacent neurons. In both species, the wide-unimodal patterns had the strongest coordinated responses as measured by the correlation coefficient. Although inhibitory relationships did not appear in correlation histograms that had been correlated for stimulus coordination, cross-correlation analysis of the raw spike trains revealed brief (10–40 ms) periods of inhibition that were associated with cat VPL neurons exhibiting wide-unimodal coordination patterns. In rat VPL, most inhibition involved longer (30–60 ms) periods of inhibitory oscillations appearing amidst a much larger rhythmic pattern. These results suggest that correlation patterns transpiring over narrow (<5 ms) time intervals represent the coordination of activity among neighboring thalamocortical relay neurons. By contrast, wide-unimodal patterns appear to represent coordinated activity between a thalamocortical relay cell and an intrinsic inhibitory neuron.