Figure 4.

Synapses conserve specific but variable Munc13-1:EYFP/PSD-95:mTurq “stoichiometries.” A, Parameter space of Munc13-1:EYFP/PSD-95:mTurq fluorescence values, obtained by plotting these values for all synapses at all time points. Data for the five synapses of Figure 3 are shown according to same color code. B, Distributions of fractional parameter space area explored by individual synapses. C, Decomposition of exploration into parallel and orthogonal components relative to “stoichiometry-conserving lines.” The slopes of these lines were calculated separately for each synapse by linear regression, forcing the offset constant to zero. D, Distributions of orthogonal/parallel travel ratios. There is a strong bias toward ratios < 1.0. E, Distributions of “stoichiometry-conserving line” slopes.