Multiple frequency functional connectivity in the hand somatosensory network: An EEG study

作者：Porcaro Camillo^*; Coppola Gianluca; Pierelli Francesco; Seri Stefano; Di Lorenzo Giorgio; Tomasevic Leo; Salustri Carlo; Tecchio Franca

来源：Clinical Neurophysiology, 2013, 124(6): 1216-1224.

DOI：10.1016/j.clinph.2012.12.004

• Functional Source Separation (FSS)
• Electroencephalography (EEG)
• Somatosensory subcortical and primary cortical network
• Low frequency oscillations (LFO)
• High frequency oscillations (HFO)
• 600 Hz
• Functional connectivity
• Granger causality
• Partial Directed Coherence (PDC)

Objective: To investigate the dynamics of communication within the primary somatosensory neuronal network. %26lt;br%26gt;Methods: Multichannel EEG responses evoked by median nerve stimulation were recorded from six healthy participants. We investigated the directional connectivity of the evoked responses by assessing the Partial Directed Coherence (PDC) among five neuronal nodes (brainstem, thalamus and three in the primary sensorimotor cortex), which had been identified by using the Functional Source Separation (FSS) algorithm. We analyzed directional connectivity separately in the low (1-200 Hz, LF) and high (450-750 Hz, HF) frequency ranges. %26lt;br%26gt;Results: LF forward connectivity showed peaks at 16, 20, 30 and 50 ms post-stimulus. An estimate of the strength of connectivity was modulated by feedback involving cortical and subcortical nodes. In HF, forward connectivity showed peaks at 20, 30 and 50 ms, with no apparent feedback-related strength changes. %26lt;br%26gt;Conclusions: In this first non-invasive study in humans, we documented directional connectivity across subcortical and cortical somatosensory pathway, discriminating transmission properties within LF and HF ranges. %26lt;br%26gt;Significance: The combined use of FSS and PDC in a simple protocol such as median nerve stimulation sheds light on how high and low frequency components of the somatosensory evoked response are functionally interrelated in sustaining somatosensory perception in healthy individuals. Thus, these components may potentially be explored as biomarkers of pathological conditions.

• 出版日期2013-6
• 单位中国人民解放军空军预警学院