Visualizing Spatiotemporal Dynamics of Somatosensory Cortex Neurons During Electroacupuncture Using Two-Photon <em>In Vivo</em> Imaging

This protocol establishes a comprehensive experimental framework for investigating cortical circuit dynamics during EA (electroacupuncture) stimulation. The methodology integrates three key components: chronic cranial window implantation in Thy1-GCaMP6f transgenic mice, standardized EA stimulation at the ST36 acupoint using 2/100 Hz biphasic pulses, and high-resolution two-photon calcium imaging. This integrated approach enables real-time visualization of neural ensemble activity in the primary somatosensory (S1) cortex with millisecond temporal precision, capturing previously inaccessible details of network-level responses to neuromodulation. The technique successfully reveals distinct layer-specific activation patterns and longitudinal plasticity changes, providing critical insights into the cortical mechanisms underlying the effects of EA. By overcoming the fundamental spatiotemporal limitations inherent in conventional fMRI and electrophysiological techniques, this high-resolution platform offers unprecedented analytical capabilities for mapping dynamic neural circuits. The protocol's robust design and reproducible outcomes make it particularly valuable for optimizing targeted neuromodulation therapies and advancing our understanding of circuit-level plasticity in response to peripheral stimulation.