Somatic Calcium Signals from Layer II/III Motor Cortex for Continuous Neural Decoding

The latest research shows that calcium signals can provide a new signal source for brain-machine interfaces (BMI). However, it remains a question whether the calcium signals from layer 2/3 motor cortex can be used for continuous neural decoding. And how they are involved in movement coding is also worth investigating. Here we collect the somatic signals in M1 layer 2/3 while mice performed a lever-press task under the one-photon imaging. We first present the potential of somatic calcium signals from layer 2/3 in continuous neural decoding through an improved recurrent neural network. Layer 2/3 neurons exhibit three types of calcium dynamics with distinct spatiotemporal coding patterns involved in the movement. Pre-pressing and pressing neurons enable sparse coding of movement through complementary spatiotemporal information. While post-pressing neurons predict the lever movement most accurately through the calcium dynamics with higher fidelity. These results demonstrate the capability of calcium signals from layer 2/3 neurons as a motor BMI driver and underscore their diversity in motor coding, opening a new avenue for studying the motor cortex and designing optical BMIs.