Studying the Coding Profiles of Somatic Stimulation on Cardiac-locked Neuronal Responses in the Rat Spinal Dorsal Horn

Many studies have suggested that electroacupuncture may be beneficial in the treatment and prevention of cardiovascular disease. However, its mechanism remains poorly understood. The thoracic spinal dorsal horn (SDH) plays an important role in integrating and modulating somatic and visceral inputs, which may then influence cardiac control. In contrast to the lumbar SDH, which has been extensively studied, thoracic SDH has been less explored due to the difficulty in surgical exposure and stereotaxic fixation. In this study, we provide a general approach for simultaneously monitoring neuronal activity and cardiac function by combining the recording of electrocardiograms and microelectrode arrays. Furthermore, we describe how to identify cardiac-locked neurons by calculating the firing rate distribution of neuronal activity in sync with heartbeats. The strategy is of great significance for studying the correlation between cardiovascular function and neuronal activity as well as for understanding the somatocardiac reflex triggered by peripheral nerve stimulations.