Spatial map of ΔΦ and current density matching the active tissue determined with LFPs. (A) Spatial map of ΔΦ during the peak of the LFP averaged across n = 7 animals. (B) Minimum norm estimate of current dipole moment Q (nA.m in each voxel) with a maximum of 1.013 nA.m/mm2 (directed into the page ⊗), based on the ΔΦ map in A. (C) Statistical significance map of the density estimate in (B). Areas shown are (p < 10−5, log scale), after Bonferroni correction. (D) The density map of the active tissue determined with LFP. Bo is rostral to caudal. In (A–C), the solid dots are the stimulating electrodes (bottom) and the open dots are the recording electrodes (top), respectively. In (D), only the stimulating electrodes are shown (as a single solid dot).