Figure 3.

The contribution of neuromuscular transmission failure to diaphragm muscle fatigue over a 2 min period of repetitive nerve stimulation and superimposed intermittent muscle stimulation across the lifespan in mice (aged 6, 18 and 24 months)

A, representative tracings for control (vehicle-treated) diaphragm muscle–phrenic nerve preparations of each age group. B, time course of neuromuscular transmission failure during repetitive stimulation in control, and BDNF-or 1NMPP1-treated preparations at each age group. In all age and treatment groups, there is progressively greater neuromuscular transmission failure over time. Data were analysed by three-way repeated measures ANOVA (age × treatment × time – repeated; P < 0.001). C, neuromuscular transmission failure following 2 min of repetitive stimulation in control, and BDNF-or 1NMPP1-treated groups. Summary data are shown to facilitate comparisons across treatment and age groups. Data were analysed by two-way ANOVA (age × treatment; interaction P < 0.001). Post hoc comparisons: *significantly different from control at the same age; ^†significantly different from BDNF at the same age; ^‡significantly different from 6 months within the same treatment; ^§significantly different from 18 months within the same treatment.