Fig. 4.

LPS treatment results in increased fronto-occipital EEG coherence in the delta and high gamma frequency bands. (A) Fronto-occipital coherence spectra calculated from EEG recordings at different time points after saline and LPS injection. Coherence data for each animal are shown in the background as thin gray lines, while the means of 6 animals are indicated by thick colored lines. An increase in delta and high gamma EEG coherence can be observed 2–8 h after the LPS treatment. (B) Average z-transformed fronto-occipital coherence values for the investigated EEG frequency bands. Delta coherence (upper panel) increased significantly 2 and 4 h after LPS treatment, while high gamma coherence (lower panel) showed a significant increase 4 and 8 h after the treatment (pair-sample t-test, n = 6). Theta and low gamma coherence (middle panels) did not show remarkable changes related to neuroinflammation. Data are shown as mean ± SD. *P < 0.05.