22 - Statistical and Computational Methods for Quantal Analysis of Synaptic Transmission

Abstract

This chapter describes some of the statistical problems that arise in the quantal analysis of synaptic transmission and highlights some numerical methods that can be used to circumvent them. When applied in appropriate circumstances, these methods can either improve the resolution of the quantal parameters or minimize the degree of nonuniqueness of the solutions. Quantal analysis is a potentially powerful tool for the study of synaptic transmission. It can be defined as the measurement of trial-to-trial amplitude fluctuations in postsynaptic potentials or currents, with the goal of separating two processes underlying synaptic transmission: (1) the presynaptic mechanisms that determine the release of neurotransmitter and (2) the mechanisms that determine the amplitude of the quantum reflecting the postsynaptic action of a single packet of transmitter. Some of the difficulties resulting from the method arise principally from attempts to extend the use of quantal analysis to synapses other than the neuromuscular junction, where the signal-to-noise ratio may be poorer and multiple presynaptic fibers innervate the target cell.