<p>A. Left: The original traces of LFPs in CA3 region from a Con rat (red line) and a Mel rat (blue line). Right: The corresponding power spectra distributing from 1 Hz to 50 Hz of the two rats. Arrows present some theta and gamma rhythms. The inserts show statistical results of relative power in theta and gamma rhythms in two groups. B. Left: The original traces of LFPs in CA1 region from a Con rat (red line) and a Mel rat (blue line). Right: The corresponding power spectrum distributing from 1 Hz to 50 Hz of the two rats. Arrows present some theta and gamma rhythms. The inserts show statistical results of relative power in theta and gamma rhythms in two groups. **p<0.01 comparison between Mel group and Con group.</p