The number of Islet-1-positive neurons in the ventral horn of C10–C11 segments
| Embryonic days | Number of Islet-1positive neurons in 8-μm-thick sections1_a | Number of Islet-1positive neurons in one segment1_b | n |
|---|---|---|---|
| E4 (st. 23) | 80.5 ± 5.1 | 3221 ± 243 | 5 |
| E4.5 (st. 24) | 60.4 ± 3.0 | 2604 ± 141* | 5 |
| E5 (st. 26) | 53.6 ± 4.6 | 2547 ± 221 | 5 |
↵F1_a Number of Islet-1-positive cell nuclei in 10-μm-thick sections were counted, and the raw numbers were adjusted by average diameter of nuclei and section thickness following the formula of Abercrombie (1946).
↵F1_b Number of Islet-1-positive neurons in 8-μm-thick sections were multiplied by length of sections (E4: 320 μm; E4.5: 345 μm; E5: 380 μm)/8 μm.
*p < 0.001 versus E4 (t test).