Fig. 4: Increasing miniature neurotransmission preserves synapses and prolongs motor ability during ageing.
From: Miniature neurotransmission is required to maintain Drosophila synaptic structures during ageing
a Representative EJC (above) and mEJC (below) traces, quantification of EJC amplitude, mEJC amplitude and frequency of HB9 neuron selective adult conditional murine Cpx rescued wild type (mCpxWT) [UAS > CpxRNAi/UAS > GFP; HB9 > Gal4, TubGal80ts/cpxSH1, UAS > mCpxWT] and mCpx ‘Helix Breaker’ (mCpxHB) [UAS > CpxRNAi/UAS > GFP; HB9 > Gal4, Tub > Gal80ts/cpxSH1, UAS > mCpxHB] mutants at 20 days after eclosion. b Representative images of presynaptic HB9 neuron boutons (red, GFP) and active zones (Brp, green), quantification of bouton diameters and percentage of boutons with only a single active zone (bouton fragmentation) of mCpxWT and mCpxHB mutants until 40 days after eclosion. Images at same magnification. c Quantification of the climbing ability of motor neuron selective adult conditional mCpx wild-type mCpxWT [UAS > CpxRNAi/OK6 > Gal4, UAS > GFP; Tub>Gal80ts/cpxSH1, UAS > mCpxWT] and mCpxHB [UAS > CpxRNAi/OK6 > Gal4, UAS > GFP; Tub > Gal80ts/cpxSH1, UAS > mCpxHB]. Unpaired two-tailed t-test, p = 0.89, n ≥ 6 presynaptic terminals per timepoint (a, EJC amplitude), p = 0.81, n ≥ 15 presynaptic terminals per timepoint (a, mEJC amplitude), ***p < 0.003, n ≥ 15 presynaptic terminals per timepoint (a, mEJC frequency). Two-way ANOVA, followed by Sidak’s multiple comparison tests were used to compare the mean of control and experimental genotypes in that timepoint, ns not significant, ***p ≤ 0.001, n ≥ 149 boutons per timepoint (b, bouton diameters), ns not significant, **p < 0.002, ***p < 0.001, n ≥ 7 presynaptic terminals per timepoint (b, single active zone boutons), ns not significant, *p < 0.033, ***p < 0.001, n ≥ 4 groups per timepoint (c). All statistical analysis details with a precise value of ‘n’ are reported in Supplementary Tables 4 and 6 and in Source Data file. Scale bar = 2 μm (b). Experiments were carried out at 29 °C. Data are represented as mean ± SEM. n = biologically independent samples.
