Figure 1.

Spontaneous locomotor recovery after spinal cord injury (SCI)

(A) Kinematics and electromyographic (EMG) recordings during treadmill locomotion before and after SCI. GL, gastrocnemius lateralis; TA, tibialis anterior.

(B) Example of a hemisection at the left thoracic level (T8-T9) with cresyl violet and luxol Fast Blue staining.

(C) Locomotor score of the ipsilesional (left) hindlimb before and after SCI (n = 15 mice, Friedman test [p < 0.0001] with Dunn’s multiple comparisons test, ∗∗∗∗p < 0.0001; ∗∗∗p < 0.001).

(D) Stick diagrams of the ipsilesional hindlimb during the swing and stance phase (arrows indicate movement direction), joint angles, and gait diagrams (bars represent the stance).

(E) Cumulative distribution function (CDF) of paw movement in reference to the iliac crest before and after SCI (n = 10 mice).

(F) Forward and backward paw placement in reference to the iliac crest (Pre-SCI vs. Week 1–7, n = 10 mice, one-way ANOVA [ p < 0.0001] with Dunnett’s multiple comparisons test, ∗∗∗∗p < 0.0001, ∗p < 0.05).

(G) Raw EMGs and raster of motor spikes of flexor and extensor muscles. LGL, left gastrocnemius lateralis; LTA, left tibialis anterior; RGL: right gastrocnemius lateralis; RTA, right tibialis anterior.

(H) Flexor activity as a function of extensor activity of the ipsilesional hindlimb (n = 9 mice). Note the loss of alternation between flexor and extensor 1 week after SCI and its recovery associated with a longer flexor activity at 4 and 7 weeks after SCI.

(I) Integrated amplitude of the ipsilesional left flexor (n = 11 mice, Kruskal-Wallis test [p = 0.0095] with Dunn’s multiple comparisons test, ∗p < 0.05).

(J) Integrated amplitude of the ipsilesional left extensor (n = 11 mice, Kruskal-Wallis test [p < 0.0001] with Dunn’s multiple comparisons test, ∗p < 0.05, ∗∗∗p < 0.001). See also Figure S1.