Table 1.

Distribution of [³H]-thymidine-labeled cells in the spinal cord of LES, LE-bo, and LE control rats

	LES						LE-bo
Age (wk)	White matter		Gray matter			White matter	White matter		Gray matter			White matter
	mean	1 SD	mean	1 SD	P	% mean	mean	1 SD	mean	1 SD	P	% mean
1	143.5	17.7	35.2	6.4	0.000026	80.3	215.5	48.8	54.5	20.5	0.0500225	79.8
2	119.2	31.4	32.2	11.1	0.001967	78.7	237.2	39.8	64.5	11.9	0.0001642	78.6
4	20.2	8.0	3	1.4	0.005466	87.1	82	11.8	15	9.1	0.0014663	84.5
8	4.5	2.9	0	0	0.021000	100	37.5	22.0	3	4	0.0021504	92.6
12	11.5	2.1	0.7	0.5	0.000058	93.9	11.7	11.4	2	2.2	0.1457714	85.4
16	18.2	1.7	1.7	1.7	0.000009	91.2	1.7	0.9	0	0	0.0448489	100
20	20	6.5	1.7	2.4	0.001861	91.9	12.7	4.9	0	0	0.0020470	100
24	13.5	5.8	1.7	2.2	0.008921	88.5	20.5	7.1	1.2	1.3	0.0017484	94.2
28	12.2	5.9	1.2	1.0	0.010375	90.7	30.2	5.8	1	0.8	0.0000588	96.8
32	6.7	2.1	2	1.8	0.014521	77.1	3.3	1.1	0	0	0.0070000	100
36	5.5	3.7	0	0	0.002486	100	2	1	0	0	0.0260000	100
40	7	2.4	0.2	0.5	0.001449	96.5	6.7	2.1	1	1	0.0130000	87
LE control
1	87	34.1	36.2	17.7	—	70.6

Labeled cells were counted in 3 sections per rat, 4 rats per age group. Internalization of [³H]-thymidine was not observed in LE control rats after 1 wk of age. One-way factorial ANOVA was used to analyze differences in distribution of [H]-thymidine-labeled cells between white and gray matter.