Fig. 3.
A comparison of the N-acetyl-aspartate (NAA) levels of the two exposure groups to the anesthesia naïve animal group. Animals in the single exposure group were given sevoflurane anesthesia for 6 h on postnatal day (PND) 7, while those in the multiple exposure group were given sevoflurane anesthesia for 2 h on PNDs 5, 7, and 10, for a total of 6 h of sevoflurane anesthesia. (A) Comparing the average z-scores between the two groups, animals in both the single and multiple exposure groups were significantly different from the unexposed controls at 2 weeks old (1 week after the exposure[s]). The multiple exposure group was significantly different (P = 0.01) from the single exposure group. (B) The differences were plotted on the sigmoid regression model derived from the unexposed controls used as a “growth chart” for NAA. This demonstrates that, although the NAA for both exposure groups continued to increase, this increase was blunted in the single exposure group, and more severely blunted in the multiple exposure group. Furthermore, based on this model, NAA for the single exposure group returned to normal expected values by 3 and 4 weeks of age, while those for the multiple exposure groups remained lower than expected.