NeuroNexus A1x16-3mm-100-703-HZ16 chronic 16-channel probes were implanted into rat somatosensory cortex and used for microstimulation as well as unit recordings to compute neuronal detection thresholds semi-weekly for 16 weeks and regularly for a period of 40 weeks post implant. Spatial resolution was key to differentiating threshold changes correlated with inflammation and scarring in different cortical layers. The results in Frontiers in Neuroscience by Morgan Urdandeta et al. with the Shelley Fried (Massachusetts General Hospital) and Kevin Otto (University of Florida) groups demonstrate that layers 4 and 5 may be the best target for chronic intracortical microstimulation (ICMS) implant longevity.