Multi-channel recordings of the motor activity from the spinal cord of behaving rats

The objective of this study was to extract voluntary motor signals from the rubrospinal tract in behaving rats and study the correlation between these volitional signals and the elbow movements. Multi-contact silicone substrate surface electrodes were implanted chronically at the cervical C5-C6 and C6-C7 levels of the spinal cord. Recordings were made during face cleaning by the animal as this task involves cyclic movements of the forelimbs and does not require any training. Temporal correlation was performed between the recordings of the proximal pair and the distal pair of contacts within a sliding window to determine whether the signals were sensory or motor. Linear regression technique was used to reconstruct the arm movement from the rectified-integrated version of the neural signals. The preliminary data show that motor signals can be successfully recorded from the cervical region of the spinal cord in behaving rats and reconstruction of elbow movements from the neural signals is feasible using these non-penetrating surface electrodes.