Electrophysiological recordings of neuronal activity. (a) Different types of electrophysiological recording probes. (b) Schematic of next-generation high-density probes inserted into the cortex and subcortical structures of the mouse brain. (c) Schematic of a silicon probe mounted on the mouse head allowing for recording during freely moving behaviors. (d) Signal traces from electrophysiological recordings associated with three individual neurons (green, magenta, and blue) based on their waveform.