Fig. 2

Automatic quantification of regenerating corticospinal axons into fluorescently labeled cell grafts following spinal cord injury. a Membrane-targeted sfGFP-AAV8 was injected into the motor cortex of C57Bl/6 mice. 5 days post injection the animals received a dorsal column lesion at cervical level 4 (C4). dsRED-positive spinal cord derived neural precursor cells (Graft) were grafted immediately into the lesion site. 4 weeks later the animals were sacrificed and sagittal sections were stained for sfGFP (Axons) and NPC-graft (Graft). b processed image showing automatically detected graft-ROI (white outline). c Separate axon channel with graft ROI. d Axon channel greyscale image cropped to graft ROI defined in “b”. e Automated tracing by AxonTracer (yellow lines) superimposed on axon channel greyscale image shows accurate axon tracing. f Semi-automated tracing by NeuronJ superimposed in purple on axon channel greyscale image produces similar tracing results to AxonTracer. g Quantification of regenerating axons in graft ROI shows high correlation between AxonTracer and NeuronJ. Mean ± SEM. p = 0.84, t test. Scale bar: a 500 μm; d–f 100 μm