Convolution of mini distributions for fitting evoked synaptic amplitude histograms

Area of Science:

• Neuroscience
• Computational Biology

Background:

• The quantal model posits that evoked synaptic currents result from the summation of individual quantal events, similar to spontaneous miniature synaptic currents ('minis').
• Analyzing the amplitude distribution of evoked currents can reveal information about neurotransmitter release, but quantal peaks are not always apparent.

Purpose of the Study:

• To present a convolution method for calculating the linear summation of miniature synaptic current amplitude distributions.
• To fit this calculated distribution to measured evoked synaptic current amplitudes to infer release statistics.

Main Methods:

• A convolution method is described to mathematically combine the amplitude distribution of miniature synaptic currents.
• This method is applied to experimental data, using asynchronous excitatory postsynaptic currents in strontium-bathed cells as a proxy for minis.
• The resulting distribution is fitted to the amplitude distribution of evoked synaptic currents.

Main Results:

• The convolution method allows for the estimation of neurotransmitter release statistics.
• This is achievable even when distinct quantal peaks are not visible in the evoked synaptic current amplitude distribution.
• The method's utility is demonstrated through a specific experimental setup.

Conclusions:

• The described convolution method provides a valuable tool for analyzing synaptic transmission and neurotransmitter release dynamics.
• The method is particularly useful in scenarios where traditional quantal analysis is limited by the absence of clear quantal peaks.
• Understanding the conditions under which miniature synaptic currents accurately represent quantal events is crucial for the method's application.