Fig. 3

Effect of PDMS implants on tissue reconstruction 3 months after lesion. a Comparison between horizontal, histological and MRI slices in a representative rat of each group (lesioned area in white). Implants visible on MRI slices (red arrowheads). Most of the time, only the position of the implant was observable on the histological slices (black arrowheads), surrounded by newly generated tissue (yellow arrows). A–P antero-posterior axis, D–V dorso-ventral axis. Scale bar: 500 μm. b Representative horizontal brain section of the lesioned area under brightfield illumination from Implants Alone (left) and hNSC Implants (right) rats. Newly generated tissue (yellow arrow) was mostly located around the PDMS implants which could still be found in place in the lesion core after cutting (red arrowhead). V ventricle, I implant position. Red ROI indicates total volume (lesion cavity, dilated ventricle, newly reorganized tissue around implants). Green ROI indicates cavity volume (lesion cavity and dilated ventricle). Scale bar: 1 mm. c Percentage of reconstruction was calculated on brightfield images in each group. Data represent individual value and median ± interquartile range. Statistical analysis carried out with the Kruskal–Wallis test followed by Dunn’s test. *p < 0.05. hNSC human neural stem cell, MRI magnetic resonance imaging