In this experiment, I employed a retrograde adeno-associated virus (Retro-AAV) expressing channelrhodopsin, injected into the spinal cord at the C6 level. This ensured precise expression in neurons projecting axons to this region, enabling targeted manipulation of motor pathways.

I implemented a novel surgical procedure that significantly increased success rates and reduced recovery time for the animals. Instead of cutting muscles, I carefully pushed them aside to minimize tissue damage. I performed a partial laminectomy to access the spinal cord while extending the animal’s back to optimize exposure. This innovative technique has proven to be highly effective and was later taught by me to researchers at other universities.

To stimulate the motor cortex, I rendered the skull transparent via cranial window surgery. Using high-resolution imaging of the skull and referencing bregma coordinates, I pinpointed the forelimb motor cortex. The laser grid was calibrated to account for the skull’s curvature, enabling precise stimulation of the cortical region. Positive hits were defined as contralateral forelimb movements in response to blue laser activation, as demonstrated in the accompanying video.

This work not only highlights the precision of targeting motor cortex function but also underscores the impact of my innovative surgical techniques on experimental outcomes and animal welfare.