Table 2. Comparison of heart rates (per min) in saline and caffeine sessions.

	Pre injection	Post injection	2% isoflurane	1.2% isoflurane	Before RORR
Saline	336.7 ± 28.2	334.3 ± 23.8	327.2 ± 26.0	346 ± 50.7	366.0 ± 24.5
Caffeine	322.0 ± 27.9	404.0 ± 61.2 *	363.5 ± 40.9	368.5 ± 45.1	388.0 ± 43.1 *

Heart rates were computed from the EEG monitor both in saline and caffeine experiments from 6 rats. Heart rates were calculated based on the unique frequency of heart rates comparing to the frequency of brain waves. Pre injection HR was used as the baseline. A repeated-measures ANOVA model was fit with condition (saline vs caffeine) and time as repeated factors. Bonferroni’s multiple comparisons post-hoc test was used to analyze the significance difference among the time points. There was no statistical difference in HR between saline and caffeine for each time point. In caffeine session, HR immediate after drug injection and before RORR were increased when compared to the HR at baseline (p<0.05). Data were expressed in Mean ± SD,

*p<0.05, n = 6.