| We report on a novel optimization principle at the organization level of the synapse. At a synapse, vesicles of neurotransmitter are released, signaling to the postsynaptic neuron of the arrival of a presynaptic action potential. The probabilities of vesicle release, however, are often conspicuously poor, for example ranging from 0.1 to 0.5 for hippocampal synapses. This observation lends itself to the question whether there is an optimality principle that would predict such small values of vesicle release as advantageous. We suggest that under the constraints of finite synaptic resources and spontaneous release processes (noise) a low transmission probability indeed optimizes synaptic transmission. We will discuss biological mechanisms which may aid the dynamic synapse in finding its "sweet spot" and those synaptic designs (and where they occur) which may benefit the most. |
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