Methodology for Studying Cortical Dynamics Underlying Acupuncture Analgesia

Objective: Acupuncture has gained global recognition primarily for its effectiveness in pain relief. Current understanding of its neural regulation mainly covers the spinal cord and subcortical nuclei, with little evidence from the cortical regions. Neural ensembles constitute basic building blocks for cortical information processing, highlighting that the mechanism underlying acupuncture analgesia may be related to its modulation on the dynamics of neural ensembles. Accordingly, this study was designed to analyze the properties of a population of neurons by introducing the general strategy. Materials and Methods: This study recorded single-unit spiking and local field potentials (LFPs) in the primary somatosensory cortex (S1). Furthermore, principal component analysis, cross-correlogram analysis, peristimulus time histogram (PSTH), joint PSTH, spectrogram, and spike-field coherence (SFC) were conducted to analyze the electrophysiological signals. Results: The representative data showed that electroacupuncture (EA) could modulate interactions between S1 neuron pairs, LFPs, and SFC, suggesting that these methods might be useful for deciphering mechanisms underlying EA from neural population properties. Conclusions: This study provides methods for studying the modulatory effect of EA on cortical activity at both levels of neural ensembles and mesoscale dynamics, which may facilitate the understanding of the neural mechanism underlying acupuncture analgesia.