Villa A E, Tetko I V, Dutoit P, De Ribaupierre Y, De Ribaupierre F
Institut de Physiologie, Faculté de Médecine, Université de Lausanne, Switzerland.
J Neurosci Methods. 1999 Jan;86(2):161-78. doi: 10.1016/s0165-0270(98)00164-2.
Microelectrode recordings were simultaneously performed at multiple sites in the medial geniculate body (MGB) of anesthetized cats, rats and guinea pigs. We studied the effect of cortical deactivation on the association of neural activity within the thalamus during spontaneous activity. The corticofugal influence was suppressed by temporary cooling of the auditory cortex. Pairs of spike trains recorded from the same electrode were distinguished from cases where units were in MGB but recorded with different electrodes. Time domain analyses included crosscorrelations and search for precise repetition of complex spatiotemporal firing patterns of reverberating thalamic circuits. As a complementary approach we performed bispectral analyses of simultaneously recorded local field potentials in order to uncover the frequency components of their power spectra which are non linearly coupled. All results suggest that new functional neuronal circuits might appear at the thalamic level in the absence of input from the cortex. The newly active intrathalamic connections would provide the necessary input to sustain the reverberating activity of thalamic cell assemblies and generate low frequency non-linear interactions. The dynamic control exerted by the cortex over the functional segregation of information processing carried out in the thalamus conforms with theoretical neural network studies and with the functional selectivity-adaptive filtering theory of thalamic neuronal assemblies. Although this general conclusion remains valid across species, specific differences are discussed in the frame of known differences of the microcircuitry elements.
在麻醉的猫、大鼠和豚鼠的内侧膝状体（MGB）的多个部位同时进行微电极记录。我们研究了在自发活动期间皮质失活对丘脑内神经活动关联的影响。通过暂时冷却听觉皮层来抑制皮质离心影响。从同一电极记录的成对尖峰序列与神经元位于MGB但用不同电极记录的情况区分开来。时域分析包括互相关以及搜索丘脑回响回路复杂时空放电模式的精确重复。作为一种补充方法，我们对同时记录的局部场电位进行双谱分析，以揭示其功率谱中非线性耦合的频率成分。所有结果表明，在没有来自皮质输入的情况下，丘脑水平可能会出现新的功能性神经元回路。新活跃的丘脑内连接将提供必要的输入，以维持丘脑细胞集合的回响活动并产生低频非线性相互作用。皮质对丘脑进行的信息处理功能分离所施加的动态控制与理论神经网络研究以及丘脑神经元集合的功能选择性 - 自适应滤波理论一致。尽管这一总体结论在不同物种中仍然有效，但在已知的微电路元件差异框架内讨论了具体差异。
