<p>(<b>A</b>) CR development was calculated using 100 trials/day for each animal during a 7-day session in 16-week-old control (open circle, n = 14) and Ngsk <i>Prnp</i><sup>0/0</sup> (experimental mice; closed circle, n = 14) mice. The top inset shows individual response topographies of averaged electromyographs (EMGs) until US onset in the control and experimental mice on days 3 and 7. (<b>B</b>) The averaged EMG amplitudes on day 7 of the acquisition session in control (n = 14) and experimental (n = 14) mice. All EMG amplitudes obtained in 1 day (100 trials) were summed, representing the average of the eyelid responses. The CR components of 250–350 ms from CS onset were masked by artifacts caused by the US. (<b>C</b>) The averaged EMG amplitudes were evaluated using only 10 CS-only trials on day 7 of the acquisition session. These analyses enable us to indicate EMG patterns in the whole CS period without the US artifacts. Values are mean ± SEM. *<i>p</i><0.05.</p
