Percentage of time spent in non-REM sleep and REM sleep and mean numbers and mean durations of full-length and aborted REM sleep bouts for spontaneously sleeping rats (n = 10)
| Behavioral stages | Rats with low % REM sleep (n = 4) | Rats with high % REM sleep (n = 6) |
|---|---|---|
| Non-REM sleep (%) | 63.5 ± 1.2 | 63.9 ± 1.2 |
| REM sleep (%) | 13.4 ± 1.1 | 19.4 ± 0.6* |
| Mean numbers of full-length REM bouts | 7.5 ± 0.64 | 11.5 ± 0.6* |
| Mean durations of full-length REM bouts (min) | 1.7 ± 0.1 | 1.85 ± 0.13 |
| Mean numbers of aborted REM episodes | 10.4 ± 0.71 | 8.1 ± 0.53 |
| Mean durations of aborted REM episodes (s) | 19.2 ± 0.6 | 14.9 ± 2.89 |
Percentages of non-REM sleep and REM sleep were calculated for a 2 h recording period before the rats were killed and were examined across the groups of spontaneously sleeping rats by unpaired t test. Percentage of non-REM sleep was not significantly different, but the percentage of REM sleep was significantly different between the two groups of rats (t(8)5.2; *p < 0.001). Rats exhibiting high percentage of REM sleep had significantly higher numbers of full-length REM bouts compared with the other group (t(8) = 5.4; *p < 0.001), whereas mean durations of REM bouts did not differ between the groups.