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. 2023 Feb 21;4(2):100946. doi: 10.1016/j.xcrm.2023.100946

Figure 7.

Figure 7

Functional improvement of intralimb coordination during treadmill locomotion upon long trains of photostimulation of glutamatergic CnF neurons after chronic SCI

(A) Kinematic and EMG recordings of the ipsilesional hindlimb evoked upon long trains of photostimulation (10 ms at 20 Hz for 1 s) of glutamatergic CnF neurons during treadmill locomotion 7 weeks after SCI (n = 5 mice).

(B) Cyclic trajectories of hindlimb joints (anchored on the iliac crest) during locomotion before and after chronic SCI. Stick diagrams illustrate the swing and stance phases (arrows show the direction of movement).

(C) Mean and SD of the hip, knee, and ankle joint angles during a normalized step cycle (512 bins). Green areas indicate the swing phase of the step cycle. Cumulative distribution function (CDF) of coefficients of variation of hindlimb joints during the swing phase (n = swing phase bins, pre vs. stim, Mann-Whitney test or unpaired t test according to the normality of the distribution). Percentage of trials in which photostimulation induced a decrease (improvement) or increase (deterioration) in coefficients of variation of hip, knee, and ankle joint angles during the swing phase (left). Individual trials (n = 25, five trials per mouse) were aligned according to the evolution of coefficients of variation of the hip angle (middle). Pie chart showing that ankle and knee stabilization occurred mainly when the hip was stabilized (right).

(D) Raw EMG recordings (top), raster of motor spikes of the LTA and LGL (middle), and rectified EMG traces of the LTA and LGL at higher magnification (below).

(E) Burst duration and integrated amplitude of background EMG bursts in the ipsilesional flexor (n = 5) and extensor (n = 4; burst duration of the ipsilesional flexor Friedman test [p = 0.009] with Dunn’s multiple comparison test, ∗p < 0.05; integrated amplitude of the ipsilesional flexor, repeated measures one-way ANOVA [p = 0.008] with Tukey’s comparison test, ∗p < 0.05). Percentage of mice showing a significant improvement (in white, decrease in burst duration, increase in burst amplitude) or no change (gray) upon photostimulation period compared with pre period (pre vs. stim periods, Mann-Whitney test or unpaired t test according to the normality of the distribution). For abbreviations, see Figure 1 legend. See also Figures S11–S13.