Figure 1
Rats presented startled awakening 21 days after traumatic stress.
(a) Experimental procedure for cortical EEG analysis. Female Sprague-Dawley rats were implanted with electrodes for sleep recording. After 7 days of recovery, the rats were placed in the communication box and subjected to footshock or psychological stress in the proestrous phase. Twenty-one days after stress exposure, to evoke trauma-related memory, the rats were returned to the communication box in the absence of footshock and sleep was recorded for 6 h. (b,d) EEG power density of 1-min sleep epoch immediately before startled awakening and normal awakening. n = 10–24 per group. Proportions of (c,e) delta (δ, 0–4 Hz), theta (θ, 4–8 Hz), alpha (α, 8–12 Hz) and beta (β, 12–30 Hz) bands. **p < 0.01, different from control group; #p < 0.05 and ##p < 0.01, different from FSC group. n = 10–14 per group. (f,g) When the rats were returned to the communication box, the freezing duration significantly increased in the FS and PS groups compared with the control group. **p < 0.01, different from control group (Student-Newman-Keuls test). The data are expressed as mean ± SEM.
