The size of the RRP and RP is reduced by NO and enhanced in NOS “null” NMJs.

<p>(A) Raw eEJC recordings of a 50-Hz train, 500 ms. (B) Mean QC for conditions indicated. (C) Cumulative QC with back extrapolated linear regression to the last 200 ms to time 0, yielding an estimated readily releasable vesicle pool size (RRP, intercept with y-axis, pool sizes in italics). (D) Mean RRP sizes for conditions indicated. NO reduces PPR sizes, with ODQ having no effects. NOS “null” NMJs show potentiated responses (ANOVA with post hoc Tukey-Kramer was used for comparisons). (E) Raw eEJC recordings of a 50-Hz train, 8 s. (F) Mean QC for conditions indicated. (G) Cumulative QC with back extrapolated linear regression to the last 2 s to time 0 (<i>w</i>^<i>1118</i> Ctrl and NO), yielding an estimated RP size (intercept with y-axis, pool sizes in italics). (H) Mean RP sizes for conditions indicated. NO reduces RP sizes similarly to RRP sizes. The raw data can be found in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.2003611#pbio.2003611.s012" target="_blank">S2 Data</a>. Student <i>t</i> test, **<i>p</i> = 0.0062, data denote mean ± SEM in all graphs. Ctrl, control; eEJC, evoked EJC; EJC, excitatory junctional current; NMJ, neuromuscular junction; NO, nitric oxide; NOS, nitric oxide synthase; ODQ, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one; PPR, paired pulse ratio; QC, quantal content; RP, reserve pool; RRP, readily releasable pool.