Table 1. Developmental sensitivity to bilirubin toxicity: the P8/P2 ratio of viability tests.

	Hip	Cll	IC	SC	Ctx
LDH
70 nM	7.11	1.12	2.20	1.43	2.40
140 nM	5.44c	0.79	3.35b	1.51	2.03
300 nM	5.51c	1.12	1.61	1.22	0.85
Hoechst
70 nM	8.95b	0.61	0.89	0.13	0.77
140 nM	12.70c	0.75	1.65	1.68	2.92
300 nM	4.97c	0.65	4.19c	0.51	0.12
MTT
70 nM	0.85	1.17	0.96	1.12	1.04
140 nM	0.69	1.18	0.86	1.27	0.78
300 nM	0.64	0.95	0.71	0.83	0.57

Lactate dehydrogenase release (LDH - upper), Hoechst staining of apoptotic bodies (middle) and mitochondrial activity (MTT - lower) were expressed as the ratio of P8 results divided by P2 results. A ratio greater than 1 demonstrates an increased sensitivity during the development for LDH and Hoechst data, the opposite for the MTT test. Statistical significance vs. DMSO ^ap < 0.05; ^bp < 0.01; ^cp < 0.001. Hip: hippocampus; Cll: cerebellum; IC: inferior colliculus; SC: superior colliculus; Ctx: cortex.