Following-up on the pioneering efforts of Nicholson, the definitive work on the application and interpretation of CSD methods to intracranial recordings was performed by Mitzdorf (1985), drawing from evidence based on micropipette recordings in cat. By careful evaluation of the biophysical properties of action potentials (fiber, dendritic, and somatic), excitatory postsynaptic potentials (EPSPs), and inhibitory postsynaptic potentials (IPSPs), she presented convincing evidence that intracranial CSD profiles disproportionately identify membrane depolarization arising from EPSPs.4 This property anchors the interpretation of CSD profiles firmly in the lineage of classical EP methods by identifying their time course and laminar specificity with ascending and intracortical processes.
