NeuroNexus 32-channel (A1x32-Poly3-5mm-25s-177-A32) and 16-channel (A1x16-Poly2-5mm-50s-177-A16) probes were inserted into the lumbar spinal cord of anesthetized Sprague Dawley rats for single-unit recordings of dorsal column (DC) axons or dorsal horn (DH) neurons during spinal cord stimulation (SCS). The high density of each polytrode design facilitated recording within specific receptive field areas. Results in eNeuro from Gilbert et al. with Warren Grill’s group at Duke University detail the spatial and electrical parameters of subperception SCS that can lead to maximizing patient pain relief via inhibition of DH neurons.