Evaluation of quantal neurosecretion from evoked and miniature postsynaptic responses by deconvolution method

Making quantal analysis more convenient, fast, and accurate: User-friendly software QUANTAN

“…We demonstrated that the results of deconvolution were in a good agreement with the distribution of m that was either simulated or obtained by direct counts at low-output synapses (Vorobieva et al, 1999). However, we also demonstrated that the accuracy of the method critically depends on the selection of input parameters ( Table 4).…”

“…Our goal here is to deconvolve the distribution of EPSC sizes and to obtain the distribution of quantal content without relying on any a priori assumptions about the variability of quantal size or the release model. We have previously developed a modelindependent deconvolution algorithm (Vorobieva et al, 1999), which uses experimentally obtained distributions of EPSCs and quanta and computes the distribution of quantal content by solving a system of regression equations. The method is based on 1) constructing the distribution of quantal sizes from either mEPSCs or unitary EPSCs recorded under low-release conditions; 2) constructing distributions of multiquantal EPSCs employing bootstrap; 3) applying multiple linear regression (Seber and Lee, 2003) to derive the distribution of m.…”

“…Our deconvolution method has been extensively tested (Vorobieva et al, 1999;Bykhovskaia et al, 2001) by analyzing simulated datasets of EPSCs, as well as by the comparison of the distributions of m obtained for low-output synapses employing the deconvolution procedure and the method of direct counts. We demonstrated that the results of deconvolution were in a good agreement with the distribution of m that was either simulated or obtained by direct counts at low-output synapses (Vorobieva et al, 1999).…”

“…In addition, measured synaptic responses may include variable contributions of noise or may be intrinsically variable. Therefore, deconvolution algorithms have been developed to extract the distribution of quantal content from the noisy distribution of EPSP sizes (Van der Kloot, 1988, 1997; Korn et al, 1993;Vorobieva et al, 1999;Bekkers, 2003;Stricker and Redman, 2003). Deconvolution methods usually rely on the information about quantal events obtained from the analysis of mEPSPs or unitary evoked EPSP.…”

“…The software performs multiple tasks required for statistical analysis of transmitter release, including filtering of electrical recordings, event detection, analysis of the release time-course, separation of synchronous and asynchronous release components, calculation of quantal content and its variability, and fitting the quantal release by binomial and Poissionian statistical models. QUANTAN combines our previously developed algorithms for direct quantal counts at low-output synapses (Bykhovskaia et al, 1996) and deconvolution of the distribution of EPSC sizes at high-output synapses (Vorobieva et al, 1999); further, it incorporates an algorithm for evaluation of the accuracy of direct quantal counts, which facilitates the choice for the appropriate detection method. Furthermore, it employs several different methods to calculate quantal content, thus possible errors can be assessed.…”