Does transection severity determine the way of spinal cord repair in the spiny mouse?

The mechanisms of the spinal cord regeneration after complete spinal cord transection were investigated in spiny mice. In some animals, the appearance of quadrupedal overground stepping together with rewiring of the direct propriospinal projections between the cervical and lumbar enlargements was revealed. In others, no stepping recovery was detected, whereas numerous cells labeled by the neuronal proteins NeuN and {beta}III-tubulin were observed within the injury region. We suggest that depending on trauma severity, different repair mechanisms are elicited: only connectome restoration or both connectome restoration and the activation of neurogenesis. To confirm the high neurogenic potential of spiny mice, a primary culture of bone marrow was established. Unlike in other mammals, bone marrow pluripotent cells in the culture differentiated into neuronal cells without any chemical stimulation. These findings provide strong evidence for the high differentiation potential of spiny mouse stem cells toward neural lineages. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=180 SRC="FIGDIR/small/739224v1_ufig1.gif" ALT="Figure 1"> View larger version (73K): org.highwire.dtl.DTLVardef@1e6f2c1org.highwire.dtl.DTLVardef@14b88f6org.highwire.dtl.DTLVardef@ce5b5org.highwire.dtl.DTLVardef@bcebd9_HPS_FORMAT_FIGEXP M_FIG C_FIG HIGHLIGHTSO_LITwo regenerative mechanisms are proposed in spiny mice, depending on the severity the spinal cord transection C_LIO_LIRegular transection evoked the emergence of the direct propriospinal projections C_LIO_LISevere transection evoked the neurogenesis within the primary injured region C_LIO_LIPrimary culture of bone marrow cells from spiny mice exhibits neurogenic differentiation without chemical induction C_LI