Arce-McShane Fritzie I, Ross Callum F, Takahashi Kazutaka, Sessle Barry J, Hatsopoulos Nicholas G
Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637;
Faculty of Dentistry, University of Toronto, Toronto, ON M5G 1G6, Canada;
Proc Natl Acad Sci U S A. 2016 May 3;113(18):5083-8. doi: 10.1073/pnas.1600788113. Epub 2016 Apr 18.
Skilled movements rely on sensory information to shape optimal motor responses, for which the sensory and motor cortical areas are critical. How these areas interact to mediate sensorimotor integration is largely unknown. Here, we measure intercortical coherence between the orofacial motor (MIo) and somatosensory (SIo) areas of cortex as monkeys learn to generate tongue-protrusive force. We report that coherence between MIo and SIo is reciprocal and that neuroplastic changes in coherence gradually emerge over a few days. These functional networks of coherent spiking and local field potentials exhibit frequency-specific spatiotemporal properties. During force generation, theta coherence (2-6 Hz) is prominent and exhibited by numerous paired signals; before or after force generation, coherence is evident in alpha (6-13 Hz), beta (15-30 Hz), and gamma (30-50 Hz) bands, but the functional networks are smaller and weaker. Unlike coherence in the higher frequency bands, the distribution of the phase at peak theta coherence is bimodal with peaks near 0° and ±180°, suggesting that communication between somatosensory and motor areas is coordinated temporally by the phase of theta coherence. Time-sensitive sensorimotor integration and plasticity may rely on coherence of local and large-scale functional networks for cortical processes to operate at multiple temporal and spatial scales.
熟练的动作依赖于感觉信息来塑造最佳的运动反应,而感觉和运动皮层区域对此至关重要。这些区域如何相互作用以介导感觉运动整合在很大程度上尚不清楚。在这里,当猴子学习产生伸舌力量时,我们测量了皮层口面部运动区(MIo)和躯体感觉区(SIo)之间的皮层间相干性。我们报告称,MIo和SIo之间的相干性是相互的,并且相干性的神经可塑性变化在几天内逐渐出现。这些相干尖峰和局部场电位的功能网络表现出频率特异性的时空特性。在力量产生过程中,θ相干性(2 - 6赫兹)很突出,并且在许多配对信号中都有表现;在力量产生之前或之后,α(6 - 13赫兹)、β(15 - 30赫兹)和γ(30 - 50赫兹)频段中相干性明显,但功能网络较小且较弱。与高频段的相干性不同,峰值θ相干性处的相位分布是双峰的,峰值接近0°和±180°,这表明躯体感觉和运动区域之间的通信在时间上是由θ相干性的相位协调的。对时间敏感的感觉运动整合和可塑性可能依赖于局部和大规模功能网络的相干性,以使皮层过程在多个时间和空间尺度上运作。