Conditioned eyeblink responses. (a) The representative EMG amplitudes of CRs of WT and RNB mice on days 1, 7, and 21 are indicated. (b and c) Data of CRs of DOX-untreated WT and RNB mice (b) and those of CRs of four lines of mice with DOX treatment and withdrawal (c) are expressed as percent CRs averaged over all animals in each group for each conditioning day. In b, n = 9 (WT) and 8 (RNB); in c, n = 6 (WT), 12 (RNB), 11 (Tet), and 6 (TeNT). Data are presented as the mean ± SEM. *, P < 0.05; **, P < 0.01; ***, P < 0.001 (DOX-treated WT mice vs. DOX-treated RNB mice). (d) Mean ± SEM of percent CRs for DOX-withdrawn WT and RNB mice as a function of conditioning block on day 21. Each block consisted of nine paired CS–US trials and one CS only at the 10th trial.