Long-term Potentiation of the fEPSP responses from Hirano Body and Control Mice. A) Summary plot of normalized fEPSP slope measurements evoked and recorded in the s. radiatum layer of the CA1 region. Open squares depict responses from the control group; closed squares represent responses from the Hirano body group; HFS (3 × 100 Hz/1 sec) was administered at time = 30 min (arrow) to induce LTP. B) Summary quantification of LTP magnitude at both 30 min post-HFS (early LTP) and 240 min post-HFS (late LTP). The open bars represent the control group; the filled bars represent the Hirano body group (**, p < 0.01, unpaired t-test). Error bars show mean ± SEM.