A new hypothesis for synaptic modification: an interactive process between postsynaptic competition and presynaptic regulation.

Based on recent physiological observations, a new hypothesis for the algorithm for synaptic modification is proposed: an interactive process between postsynaptic competition and presynaptic regulation controls the synaptic modification, and both functions obey the same competitive rule. A fundamental algorithm for the competitive rule is proposed and analysed. The interactive process is deomposed into two procedures. The first one is a postsynaptic competition, in which all synapses making contact with the same postsynaptic cell compete for their terminal sites, and the postsynaptic cell makes demands for synaptic modification upon the presynaptic cells. The second one is a presynaptic regulation, in which the presynaptic cell regulates the postsynaptic demands and determines the net amount of the modification for each snyapse originating from it. The performance of the alforithm has been simulated on a digital computer. The initial structure of the simulated neural network consists of randomly-connected presynaptic and postsynaptic cells, with no other structures assumed. After repetitive presentations of a uniform stimulus, the basic configurations of neural connections (one-to-one, one-to-many, many-to-one and many-to-many connections) are organized in dependence on the parameters of the algorithm.