both by pre- and postsynaptic mechanisms of control, and a part of this variability
seems to be of stochastic nature (for a review see [8]). In the following we will
examine some (but not all) regulatory mechanisms which imply modulation of
variability of the postsynaptic response and their possible stochastic and/or deterministic nature. Some of the processes which produce synaptic response variability
are external to the synapse and will be considered in an appropriate section.
2.1 Intrasynaptic factors of the EPSP variability
For intrasynaptic factors we mean those mechanisms operating at the level of
the AZ or to the PSD area. For extrasynaptic we mean any influencer located or
operating out of the synaptic “cylinder.” Intrasynaptic factor can be divided into
pre- and postsynaptic factors influencing the EPSP variability.
2.1.1 Presynaptic-dependent EPSP variability
A first point to stress about the presynaptic source of variability is that the
probability of release of a vesicle following a presynaptic spike is not 1 and the range
Figure 1.
Information flow by synaptic transmission.
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Information Processing and Synaptic Transmission
DOI: http://dx.doi.org/10.5772/intechopen.88405