In their Science Advances publication, Sohn et al. from Yoshiyuki Kubota’s group at the National Institute for Physiological Sciences (NIPS) in Japan and Matthew Larkum’s group at Charité in Berlin used NeuroNexus acute, 16-channel probes (A1x16-5mm-100-177-A16) to record M1 neurons during optogenetic inactivation of M2 in C57BL/6J mice. Electrode sites spanned 100µm to 1600µm below the pial surface. Their study characterizes two presynaptic connections involved in pyramidal neuron spine dynamics during motor learning. Transient spines appear and disappear at corticocortical connections, while new and enlarging spines appear at thalamocortical connections.