Fig. 3
To further explore the effects of spinal cord compression and decompression serotonergic axons were visualised by immunohistochemical staining for 5HT. a-d Compression resulted in a significant decrease of 5HT positive axons in white matter tracts above and at the site of cord compression (**p < 0.01, ****p < 0.0001. On the other hand, the presence of 5HT fibres increased significantly at and below of the area of cord compression following surgical decompression. e-h Quantification of 5HT+/synaptophysin + axons in the grey matter demonstrated a decrease in functional serotonergic innervation at and below the lesion site (**p < 0.01, ****p < 0.0001). Following decompression, a significant increase of 5HT+/synaptophysin + axons was detected (***p < 0.001, ****p < 0.0001), which points to the presence of axonal sprouting. j-l Axonal sprouting was further confirmed by immunohistochemistry for GAP43, which indicated an increase of GAP44+ axons below the lesion site following decompression (***p < 0.001, ****p < 0.0001). Scale bar: b-d, f-h = 100 μm; j-l = 30 μm