Pattern dependent form of synaptic modification and its quantal origins

Presynaptic mechanisms of post-activation changes of synaptic efficacy have been quantitatively reconstructed via computer simulations with the previously suggested double-barrier quantal model of a chemical synapse. Successful in predicting the global changes in synaptic efficacy during and after short trains of presynaptic impulses, computer reconstructions have revealed in the post-activation period the stimulus dependent form of synapse modification from short-term to longer-term plasticity. An analysis of the quantal origins of the phenomenon suggests semantic or S-pattern as the trigger of the phenomenon. The property of a semantic pattern to modify synaptic plasticity is presented in the form of the rule of S-pattern dependent synaptic modification or S-modification.