Mai Iwasaki et al., supervised by Valery Grinevich and Alexandre Charlet, generated and studied a novel transgenic rat line (OTR-IRES-Cre) to label oxytocin receptor-expressing neurons. They identified OTR-expressing neurons in the ventrolateral periaqueductal gray (vlPAG) and used NeuroNexus Q1x1-tet-10mm-121-OAQ4LP optoelectrodes to optically drive oxytocin release. Using NeuroNexus Q1x1-tet-5mm-121-Q4 acute probes, they further recorded wide dynamic range neurons within the spinal cord. Their study in Nature Communications demonstrates that increased vlPAG activity resulted in analgesia in the rats via suppressed sensory neuron activity in the spinal cord.