Fig. 4

Decrease in interlimb coordination of β-III^−/− mice compared to age-matched controls. (a) Box plots for regularity index of β-III^−/− (light coloured boxes) and control mice (dark coloured boxes) at 6–8-weeks (6-8w; blue), 6–8- months (6–8 m; orange) and 18–20-months (18–20 m; green) of age. Statistical differences between control and β-III^−/− animals of the same age denoted by *; between β-III^−/− animals of different ages denoted by #. (b) Schematic representation of phase dispersion for RF-RH (anchor-target) paws. Calculation is based on “a” the step cycle duration of the anchor paw (RF) and “b” the length of time into the anchor paw’s step cycle when the target paw (RH) makes first contact (initial contact of target paw – initial contact of anchor paw/step cycle of anchor paw x 100%). (c) Quantification of average phase dispersion of the six different paw combinations for 18–20-month-old animals. β-III^−/− mice (light green), compared to age-matched controls (dark green), have significantly reduced phase dispersion for lateral and girdle paw pairs, except for LF > RF, and significantly increased phase dispersions for diagonal paw pairs (d) Quantification of the variability in average phase dispersion of the six paw combinations for 18–20-month-old animals. β-III^−/− mice (light green), compared to age-matched controls (dark green), have significantly greater variability for all paw combinations. Data (N = 10–16) plotted as median, quartiles (25th and 75th percentiles), minimum and maximum with mean indicated by cross.