Differences in the PSD of LFPs recorded in the hippocampal CA1 area during different states of neuronal activation.

(A) Scheme of the experimental protocol used. (B-G) PSD plots for the LFP activity recorded during baseline (WT, in B; GABA_B1a^-/-, in E), and before (WT group, in C; GABA_B1a^-/- group, in F) and after (WT group, in D; GABA_B1a^-/- group, in G) kainate injection (8 mg/kg). Colored arrows in B-G indicate the dominant frequency of the spectra [PSD values, in log (mV/√Hz) are indicated on the y-axis; corresponding frequencies, in log (Hz), are indicated on the x-axis]. The mean values of the represented traces are indicated by the colored traces. (H) Histograms representing PSDs corresponding to each group and the three different recording situations [baseline (BL, green and red histograms), and before (light green and light red histograms) and after (dark green and dark red histograms) kainate administration]. (I) Histogram representing the dominant frequency of the LFP activity recorded during baseline (BL, green and red histograms), and before (light green and light red histograms) and after (dark green and dark red histograms) kainate injection for both genotypes. Note in H and I that the maximum PSD value and the minimum value of the fundamental frequency was recorded in the GABA_B1a^-/- group following HFS after injection of kainate. For both H and I, collected data was quantified for each experimental animal (n = 5 per group) and then averaged. *, P < 0.05; **, P < 0.01; ***, P < 0.001.