Does the fusion pore contribute to synaptic plasticity?

How synapses change their strength in response to impinging neural activity is a fundamental issue for understanding how the brain molds its circuitry in response to behavioral experience. Although a growing number of studies reveal the involvement of postsynaptic changes contributing to synaptic plasticity in brain circuits, the involvement of presynaptic factors has been implied by several studies. Most recently, several works point to the mechanism of vesicle fusion as a new possible locus for the modification of presynaptic synaptic strength. However, it is not yet clear to what extent such changes affect the simplest form of information transfer in the brain--the transmission of a single action potential.