Fig. 4: Stereological analysis of hNSC fate and distribution along the spinal cord.

a Schematic of spinal cord injury, showing the lesion epicenter at C5 and indications of coordinates in µm. ‘X’ represents locations of hNSC transplantation at two injection sites rostral and two sites caudal to the lesion epicenter. Ipsilateral refers to the same side as the lesion, and contralateral refers to the side opposite the lesion. Dashed lines represent rostral-caudal axis binning used for histological quantification (720, 1440, 2160 microns from lesion epicenter). b, c Representative images of a coronal spinal cord section showing the distribution of STEM121⁺ transplanted human hNSC (red) and total cell nuclei (blue) in the SCI control group (b) and PLG bridge group (c); inset shows higher power. d Stereological quantification of the total number of STEM121⁺ cells in rostral and caudal regions in PLG and SCI control groups. The graph represents Mean ± SEM. Statistical analysis by unpaired Student’s two-tailed t-tests. e–g Distribution of transplanted STEM121⁺ hNSC in the spinal cord: e ipsilateral and contralateral combined; f ipsilateral; and g contralateral. h–s Representative images and quantification for cell fate. STEM121⁺/OLIG2⁺ oligodendrocytes: h Immunostaining; i ipsilateral; j contralateral. STEM121⁺/DCX⁺ neuronal precursors: k Immunostaining; l ipsilateral; m contralateral. STEM121⁺/NeuN⁺ mature neurons: n Immunostaining; o ipsilateral; p contralateral. STEM121⁺/GFAP⁺ astrocytes: q Immunostaining; r ipsilateral; s contralateral. Statistical analysis by unpaired Student’s two-tailed t-tests (*p ≤ 0.05, **p ≤ 0.005; Mean ± SME; n = 3–6/group). Scale bars: b, c 200 μm; c-inset, h, k, n, q 10 μm.