現実的な皮質ニューロンモデルの回路において生成される自発的な二状態間遷移

Abstract

Recent studies have revealed that in vivo cortical neurons show spontaneous ‘UP-DOWN’ transitions between the two subthreshold levels of the membrane potentials, i.e., ‘UP’ state and ‘DOWN’ state. The neural mechanism of generating those spontaneous state transitions, however, remains unclear. Recent electrophysiological studies suggested that those state transitions may occur through activation of a hyperpolarization-activated cation current (H-current, Ih) by inhibitory synaptic inputs (Cossart et al., 2002). To show that the spontaneous state transitions can be generated by a network-based mechanism, we study learning processes in a computational model of cortical networks. We now found that the spontaneous ‘UP-DOWN’ transitions similar to those exhibited by in vivo neurons can be self-organized through spike-timing-dependent plasticity in a network of inhibitory neurons and excitatory neurons expressing the H-current.