(A) Schematic and representative traces illustrating that overexpression of a constitutively active form of CaMKII only on muscle 6 (M6>CaMKIIT287D) has no significant impact on neurotransmission. (B–D) Quantification of mEPSP amplitude (B), EPSP amplitude (C), and quantal content (D) in the indicated muscles. (E) Schematic and representative traces illustrating that expression of constitutively active CaMKII with GluRIIA knock down (M6 > GluRIIARNAi + CaMKIIT287D) on muscle 6 inhibits the retrograde potentiation of presynaptic glutamate release. (F–H) Quantification of mEPSP amplitude (F), EPSP amplitude (G), and quantal content (H) in the indicated muscles. Asterisks indicate statistical significance using a Student’s t test: (**) p<0.01; (***) p<0.001; (ns) not significant. Error bars indicate ± SEM. Detailed statistical information for represented data (mean values, SEM, n, p) is shown in Supplementary file 1.