MAKING QUANTAL ANALYSIS EASIER AND MORE ACCURATE

Problems inherent in applying quantal analysis to synapses are discuss ed. These include the dispersion in time of the evoked quantal release s and the skew to the right in the distribution of the sizes of the sp ontaneous miniature potentials. To circumvent some of the problems, qu antal analysis was performed at the neuromuscular junction by dividing each individual endplate current (EPC) by the mean miniature endplate current (MEPC) or each individual time integral of the endplate curre nt (integral EPC) by the mean integral MEPC. The results were evaluate d by comparing the resulting distributions to the predictions of Poiss on's law, based on the number of stimuli not followed by a response. T he quantal distributions obtained from the integral MEPCs by this 'poi nt-by-point' were in excellent agreement with these predictions. This method may make quantal analysis easier and more reliable. (C) 1997 El sevier Science B.V.