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. Author manuscript; available in PMC: 2010 Dec 6.
Published in final edited form as: Nat Neurosci. 2009 Oct 11;12(11):1415–1423. doi: 10.1038/nn.2417

Figure 6. α2δ-3 null embryos have spontaneous minis, but no evoked synaptic transmission.

Figure 6

Whole-cell patch recordings from embryonic muscles 6 and 7 were performed in voltage-clamp in a modified HL-3 saline containing 1 mM Ca2+ (see Methods). a. Representative traces of spontaneous miniature junctional currents in wildtype, α2δ-3106/106 null and α2δ-3196/196 (“δ-less”) alleles. Average amplitude ± SEM in pA was 85.3 ± 0.6 for wt, 72.0 ± 0.5 for α2δ-3106/106, and 81.5 ± 1.1 for α2δ-3196/196 alleles; N (embryos) = 8 wt, 11 α2δ-3106/106, 4 α2δ-3196/196. Scale bar: 30 pA, 10 s. b. Representative individual minis. Scale bar: 30 pA, 20 ms. c. Mini amplitudes are normal in α2δ-3 mutants, but mini frequency is reduced in α2δ-3106/106 NMJs, from 0.11 ± 0.03 minis/s in wt to 0.04 ± 0.01 minis/s in α2δ-3106/106 nulls. α2δ-3196/196 alleles exhibited normal mini frequency (0.12 ± 0.06 minis/s. p < 0.01, ANOVA with Dunnett posthoc test. d. Overlayed representative evoked responses (10 traces) in 5 mM Ca2+. α2δ-3106/Df(2R)Ex7128 NMJs have no evoked response, while α2δ-3196/Df(2R)Ex7128 NMJs have greatly reduced responses. e. Average evoked responses were obtained from 4 (wildtype), 8 (α2δ-3106/Df(2R)Ex7128), and 4 (α2δ-3196/Df(2R)Ex7128) recordings from different embryos, and 10–40 stimuli per recording. Average amplitude ± SEM in pA was 802 ± 113 for wt, and 76 ± 23 for α2δ-3196/Df(2R)Ex7128; N (embryos) = 4 wt, 4 α2δ-3196/Df(2R)Ex7128. Scale bar = 250 pA, 10 ms in (d, e). Stimulus indicated by black bar above trace.