A. In the HI group for E22, the ratio of attached neurons with functioning mitochondria (Rhodamine + Cholera + cells at 48 h) over total neurons with functioning mitochondria (in supernatant at 24 and 48 h plus attached at 48 h) was the lowest in thalamus in a BH4 deficient environment (ANOVA p<0.0001; * p=0.0002 vs basal ganglia and p=0.0007 vs cortex, paired t-test). B. Attachment efficiency of functioning mitochondria neurons: With BH4 supplementation, this ratio significantly increased in thalamus (# p=0.0099, paired t-test) but not in basal ganglia and cortex. C. Attachment efficiency of high mitochondria cells: In the E22 HI group, thalamus had the lowest ratio of attached cells with healthy mitochondria (JC-1 red>green fluorescent cells at 48 h) to total cells with healthy mitochondria (in supernatant at 24 and 48 h plus attached at 48 h) without BH4 supplementation (ANOVA p=0.0313; *p=0.0098 thalamus vs basal ganglia, paired t-test). D. With BH4 supplementation, there are no increases in recovery of this ratio in any of the groups.