A Computational Model of Hippocampal-VTA Microcircuit: Why Expectation of Reward in Rat Striatum at Choice Point Is Covert?

Hippocampal-VTA microcircuit is one of the most important components of reward system. As a prominent feature in hippocampus, theta rhythm involves a strong correlation with learning, memory and decision making. However, the relation between theta rhythm and reward representation remains unclear. Based on some recent experimental discovery, a computational model of hippocampal-VTA microcircuit was proposed. By means of population activity analysis, dis-inhibition effect of dopamine neurons in VTA caused by enhanced CA3 theta rhythm can illustrate theoretically why expectation of reward in rat ventral striatum at choice point is covert.