Fig. 3.

NMJ transmission defects correlate with normalized grip strength. a–b Increased single-fiber electromyography jitter (NMJ variability, mean consecutive delay) was correlated with lower normalized gastrocnemius weight (a Pearson r=−0.6924, p=0.0042) but not normalized grip (b Pearson r=−0.3430, p=0.1934). c–d Similarly, increased single-fiber electromyography blocking (NMJ failure) correlated with lower muscle weight (c Spearman r_s=−0.5738, p=0.0278) but not normalized grip (d Spearman r_s= −0.4598, p=0.0745). e–f Greater RNS CMAP amplitude decrement (loss) correlated with lower gastrocnemius muscle weight normalized to body weight (e Pearson r=0.6147, p=0.0148) and lower grip strength normalized to body weight (f Pearson r=0.6009, p=0.0138). Muscle weights: young rats, n=8 (3 females, 5 males), and aged rats, n=7 (3 females, 4 males). Grip: young rats, n=8 (3 females, 5 males), and aged rats, n=8 (3 females, 5 males)