FIGURE 3.

Endogenous tagging of unc-13 leaves synaptic function and presynaptic homeostatic potentiation undisturbed. (A) Representative traces of miniature excitatory postsynaptic currents (EPSCs) recorded in 1 mM Ca²⁺ at wildtype (wt, black) and unc-13^GFSTF (green) neuromuscular junctions (NMJs). (B) miniature excitatory postsynaptic currents (mEPSC) amplitude and frequency are unaltered in unc-13^GFSTF larvae (green, n = 13 NMJs from seven larvae) compared to wt (black, n = 13 NMJs from eight larvae). (C) Representative traces of evoked EPSCs recorded in 1 mM extracellular Ca²⁺ in both genotypes. (D) Evoked excitatory postsynaptic currents (eEPSC) amplitude, quantal content, and paired-pulse-ratios measured with different interpulse intervals (IPI; 10, 30, 100, 300, and 1000 ms) remain unaltered in unc-13^GFSTF animals (wt: n = 14 NMJs from eight larvae; unc-13^GFSTF: n = 14 NMJs from seven larvae). (E) eEPSC amplitude, mEPSC amplitude and quantal content in wt (black) and unc-13^GFSTF (green) animals treated with Philanthotoxin (PhTx) in dissolved in dimethyl sulfoxide (dmso) (+, open circles) or dmso (–, filled circles). unc-13^GFSTF larvae still exhibit presynaptic homeostatic potentiation in response to PhTx stimulation (wt: 10 NMJs from seven larvae in dmso, 10 NMJs from five larvae in PhTx; unc-13^GFSTF: 13 NMJs from six larvae in dmso, 14 NMJs from seven larvae in PhTx). Whisker plots represent mean ± SEM, scatter plots show individual data points, individual p-values are indicated.