Figure 2-1
Mere exposure to the experimental context and tone are not sufficient to produce alarm calls, and shock-driven alarm calls are also observed during the ITIs. A–C, Bar graph showing the total number of USVs across the whole trial (A), the total number of USVs emitted during the baseline (B), and the total number of alarm calls (C) emitted by male and female rats exposed to the same testing procedure, chamber, and tones as those in Figure 1, but with no footshocks. D, Line graph showing the percentage of time spent freezing during baseline (first 2 min only) and each tone of animals exposed to only the tones without shocks. E, Line graph depicting the rate of alarm calling of male and female rats in each shock intensity group (0.3, 0.5, and 1 mA) during the ITIs. F, Line graph showing the mean alarm call length as measured during each tone and ITI, separately for males and females. N values: A–D: 13 males, 12 females; E: 67 males (0.3 mA, 21; 0.5 mA, 33; 1 mA, 13), 67 females (0.3 mA, 20; 0.5 mA, 33; 1 mA, 14); F: 50 males, 37 females (non-alarm callers excluded). Bar graphs depict the mean ± SEM, and each dot represents a single animal. Symbols along line graphs indicate the mean ± SEM. Download Figure 2-1, file.