Figure 1.

Power of CA1 stratum radiatum KA-induced gamma-band activity injection is attenuated by deletion of S100B. Traces for WT and S100B(−/−) are shown in blue and red, respectively. A, A representative experiment shows that gamma oscillations in CA1 stratum radiatum after KA injection is smaller in the S100B(−/−) animal. The traces are local field potential recordings in CA1 stratum radiatum. B, Group comparison of the gamma-band (30–80 Hz) local field potential amplitudes shows similar amplitudes in 0–10 min before KA injection (left graph; mean ± SEM; WT, n = 9; S100B(−/−), n = 11; p = 0.75) but reduced amplitudes in S100B(−/−) animals 40–50 min after KA injection (right graph; mean ± SEM; **p < 0.001). C, Time course of the gamma-band amplitude is plotted for WT and S100B(−/−) animals (mean ± SEM). For each experiment, the gamma-band amplitude is normalized to the averaged magnitude during control period. D, Power spectra from 30 to 50 min after KA injection in WT and S100B(−/−) animals (mean ± SEM). Note a significant difference ∼40 Hz (*p < 0.05). Gamma-band spectral peak is evident (arrow). a.u., Arbitrary units; Ctrl, control (in this and subsequent figures).