Recording Forelimb Muscle Activity in Head-Fixed Mice with Chronically Implanted EMG Electrodes

I'm interested in how parts of mouse motor cortex, called primary and secondary motor cortex, interact with each other to influence muscle activity during different kinds of movements. So we know that both primary and secondary motor cortex project to the spinal cord, but it's unclear how they differentially influence movement. So I'm using this protocol to compare the effects of inactivating primary and secondary motor cortex on forelimb muscle activity throughout movement to understand how they differentially control movement.

The use of forelimb muscle EMG has enabled us to measure the impact of optogenetic inactivation of different motor system regions on motor output. For example, we've been able to show that direct motor cortical influence on muscles is specific to certain motor behaviors and particular muscle activity states during those behaviors. New large-scale multi-electrode arrays like Neuropixels now enable us to record from large neuronal populations across multiple motor system regions simultaneously.

Performing EMG recordings during these neural recordings will enable us to characterize how the interactions between these motor system regions depend on muscle activity state.