Table 2.

Appearance and distribution of O1⁺ cells in the human fetal spinal cord at different postconceptional ages

Age (dpc)	No. of specimens analyzed	Ventral half			Dorsal half
		Adjacent to VZ	Either side of the floor plate	Lateral forming white matter	Lateral forming white matter*
45 –49	4	−	−	−	−
53 –54	3	+	+	−	−
57 –59	5	+	+	+	−
74 –83	5	+	+	+	+*

Presence (+) or absence (−) of O1⁺ cells in the spinal cord sections.

^*Fewer O1⁺ cells were found in the dorsal as compared with ventral parts of the cord at these ages.