Spike Timing-Dependent Plasticity in the CA1 Pyramidal Neuron in a Modeled Hippocampal Circuit

Spike timing-dependent plasticity (STDP) plays an important role in sculpting information-storing circuits in the hippocampus, since motor learning and memory are thought to be closely linked with this classical plasticity. To further understand the information delivery in a hippocampus circuit, we build a computational model to study the potential role of linear changes in the synaptic weight and synaptic number. Several key results have been obtained: (i) Changes in the synaptic weight and numbers lead to different long-term modifications; (ii) the first paired spiking from two neurons significantly influences the adjusted subsequent paired spiking; the pre-post spiking pair strengthens the following paired spiking; however, the post-pre spiking pair depresses the subsequent spiking; (iii) when the synaptic weight and synaptic numbers are changed, the interval of the first spiking pair may undergo reduction, and (iv) when we stimulate a stellate neuron weakly or decrease the capacitance of the CA1 pyramidal neuron, LTP is more easily produced than LTD; on the contrary, LTD is more easily produced in an opposite situation; increase in the synaptic numbers can promote activation of the CA1 pyramidal neuron.