Fig. 1
From: MeCP2 deficiency impairs motor cortical circuit flexibility associated with motor learning
Chronic in vivo Ca2 + imaging on area M1 neurons of Mecp2-null (Null) mice and wild type (WT) littermates during rest and locomotion. A Left, Experimental time frame of chronic in vivo Ca2 + imaging. Right, Paradigm for studying locomotion in area M1. This involves accommodating the animals to run on a wheel that controlled by a motor which allows to set the speed of the wheel at variable levels (left) and monitor the neuronal activity of motor cortical neurons expressing GCaMP6m via viral infection (right) under two-photon microscope. B Capture of mouse locomoting on the treadmill during Ca2 + imaging under 2-photon microscope. The arrow heads point to the left and right paw, showing the alternative orientation of two paws from WT mice (top) and parallel orientation from Mecp2-null (mice) during locomotion. C Temporal trace of left and right paw position on the treadmill. X axis represents the time, and the Y axis represents the estimated paw location. The WT mouse makes large steps and mostly alternates between left and right forelimbs, while the Mecp2-null mouse’s movements are smaller and locomotion is irregular indicative of impaired motor coordination. D Averaged stride length (top), locomotion distance (middle) and stride number (bottom) at each speed at the age of 6 and 7 weeks, 9 and10 weeks and the week when the Mecp2-null mice died. Black, WT (n = 12); Blue, Mecp2-null (n = 15). F (1, 84) = 16.56; P = 0.0001 for Stride length of 6–7 weeks old; F (1, 68) = 42.50; P < 0.0001 for Stride length of 9–10 weeks old; F (1, 84) = 49.88; P < 0.0001 for Stride length of week of death; F (1, 84) = 70.96; P < 0.0001 for Distance of 6–7 weeks old; F (1, 68) = 106.6; P < 0.0001 for Distance of 9–10 weeks old; F (1, 84) = 164.5; P < 0.0001 for Distance of week of death; F (1, 84) = 124.0; P < 0.0001 for Stride number of 6–7 weeks old; F (1, 68) = 121.4; P < 0.0001 for Stride number of 9–10 weeks old; F (1, 84) = 130.5; P < 0.0001 for Stride number of week of death; P values are from the main effects of Two-way ANNOWA test. E Ratio of averaged stride length (top), locomotion distance (middle) and stride number (bottom) between Mecp2-null and WT groups at speed 60 mm/sec at the age of 6–7 weeks, 9–10 weeks and the week when the Mecp2-null mice died, showing the regression of locomotion behavior