Supplementary Figure 1: Electrode locations and characteristics of local field potentials.
From: Bidirectional prefrontal-hippocampal interactions support context-guided memory
(a) Locations of electrode tips in prefrontal cortex (mPFC), dorsal hippocampus (dHPC), and ventral hippocampus (vHPC) at mm AP to bregma: mPFC 3.20; dHPC 3.14; vHPC -5.60. mPFC electrodes were localized in layers II/III (n=7); dHPC in the pyramidal layer (n=6); vHPC in the pyramidal layer (n=2) or stratum radiatum (n=2). (b) Frequency spectra show prominent power spectral density in the theta band during both the context exploration (Peak Frequency = 8.13 +/− 0.61 Hz, mPFC; 8.93 +/− 0.15 Hz, dHPC; 9.11 +/− 0.15 Hz, vHPC) and object sampling periods (Peak Frequency = mPFC: 8.3 +/− 0.43 Hz; dHPC: 8.79 +/− 0.14 Hz; vHPC: 9.03 +/− 0.13 Hz). (c) Mean coherence between dHPC and vHPC and mPFC was maximal at theta frequency both for the context exploration (Peak Frequency = dHPC-mPFC: 9.57 Hz +/−0.17 Hz; vHPC-mPFC: 9.51 +/− 0.23 Hz) and object sampling periods (Peak Frequency = dHPC-mPFC: 9.34 +/− 0.21; vHPC-mPFC: 8.91 +/− 0.14 Hz). Shading indicates S.E.M. (d) Peak power frequency during first 1-s of context exploration and object sampling did not significantly differ among areas (One-way ANOVA F1, 30 = 0, p = 0.97 +/− S.E.M. (e). Peak Coherence Frequency during first 1 s of context exploration and versus object sampling did not significantly differ (One-way ANOVA, F1, 18 = 3.49, p = 0.08). Coherence values for these frequencies were greater than those predicted by 95% jackknife-estimated confidence intervals (0.1069) for both context exploration (Coherency = dHPC-mPFC: 0.47 +/− 0.04; vHPC-mPFC: 0.38 +/− 0.02) and object sampling (Coherency = dHPC-mPFC: 0.42 +/− 0.05; vHPC-mPFC: 0.32 +/− 0.02).
