Table 1.

The cell viability of cultured hippocampal neurons by MTT-test ^1,2,3

Time (day)	Al level (×104 μM)			Time effect
	0	37	74
7	1.2 ± 0.3 CY	3.8 ± 0.8 BY	5.4 ± 1.2 AY	3.9 ± 1.8 Y
14	3.0 ± 1.2 BX	5.8 ± 1.5 BX	8.4 ± 2.6 AX	6.3 ± 2.8 X
Dosage effect	2.1 ± 1.3 C	4.8 ± 1.5 B	6.9 ± 2.5 A

^1. All values are Mean ± SD (cell numbers).

^2. Values in the same row with different ^{A, B, C} superscripts are significantly different at α = 0.05 level.

^3. Values in the same column with different ^{X, Y} superscripts are significantly different at α = 0.05 level.