Wang Jin-Yan, Chang Jing-Yu, Woodward Donald J, Luo Fei
Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, 10A Datun Road, Chaoyang District, Beijing 100101, China.
Neurosci Lett. 2008 Apr 18;435(2):163-8. doi: 10.1016/j.neulet.2008.02.028. Epub 2008 Feb 20.
Considerable evidence supports that pain is encoded in a large, widespread network that consists of the thalamus, cortex, as well as limbic system. However, the temporal properties of the neural matrix in pain processing were largely unknown. In the present study, we simultaneously recorded thalamic and cortical neuronal discharges elicited by brief noxious or innocuous electrical stimulus in awake rats. The discrimination performance of the neural ensembles in differentiating noxious from innocuous inputs was calculated using different window sizes at the millisecond and second level, respectively. The results demonstrated that coding information emerged in a quantum-like manner; the minimum spike-train length for discriminating noxious from innocuous inputs was 40 ms. The nociceptive coding activity was temporally dynamic, and could be preserved for a relatively long time (3-4 s) within the thalamocortical loops, independent of the initial brief stimuli. These results suggest that the nociceptive signals may be reverberatory within the thalamocortical loops, hence keeping the neurosignature for central pain representation.
大量证据支持疼痛是在一个由丘脑、皮层以及边缘系统组成的庞大、广泛的网络中进行编码的。然而，疼痛处理过程中神经基质的时间特性在很大程度上尚不清楚。在本研究中，我们在清醒大鼠中同时记录了由短暂有害或无害电刺激诱发的丘脑和皮层神经元放电。分别在毫秒和秒水平使用不同的窗口大小计算神经群体区分有害输入和无害输入的辨别性能。结果表明编码信息以类似量子的方式出现；区分有害输入和无害输入的最小脉冲序列长度为40毫秒。伤害性编码活动在时间上是动态的，并且可以在丘脑皮质环路中保留相对较长的时间（3 - 4秒），与最初的短暂刺激无关。这些结果表明伤害性信号可能在丘脑皮质环路中回荡，从而保留中枢性疼痛表征的神经特征。
