Figure 5: Establishment of an in vivo model of axon regeneration across the dorsal root entry zone.
From: Genetic dissection of axon regeneration via in vivo electroporation of adult mouse sensory neurons
(a) Axons of L4 DRG enter the spinal cord at about the L2 level of the vertebrate. (b) Spinal cord cross-section above the L2 level at 7 days after in vivo electroporation of L4 DRG. Note that EGFP-labelled axons were detected in the spinal cord. (c) A representative image from a control mouse transfected with EGFP by in vivo electroporation of L4 DRG. Note that EGFP-labelled dorsal root axons entered the spinal cord dorsal column. (d) Higher magnification image of the indicated areas in panel c (yellow arrow) for the dorsal column. (e) Higher magnification image of the indicated areas in panel c (red arrow) for the DREZ. (f) A representative image from a mouse that was injured by crushing in the middle of the dorsal root (cyan arrow). At 2 weeks after the crush, EGFP-labelled dorsal root axons regenerated within the dorsal root until they encountered the DREZ, where they stopped abruptly (white arrow). (g) Higher magnification image of the indicated areas in panel f (white arrow) for the DREZ. (h) Higher magnification image of the indicated areas in panel f (cyan arrow) for the crush site in the dorsal root. Scale bars, b,d,e,g,h, 400 μm; c,f, 1,000 μm.
