マイクロパターン基盤上に培養した単一神経細胞における概日時計の光イメージング解析

抄録

The circadian rhythm in the suprachiasmatic nucleus (SCN), the master clock of the mammals, is considered to be based on single neurons with an intrinsic circadian oscillation, which are integrated by mutual synchronization through the neural or humoral mechanism. However, it is still a matter of discussion whether only a fraction of SCN neurons in the SCN can generate intrinsic rhythms and the most of other cells are just enforced or driven by a set of oscillating neurons. In this study, circadian rhythms in intracellular Ca²⁺ were measured from a solitary SCN neuron which was physically isolated from other cells. Dispersed cells were cultured on a platform of microisland in a culture dish. Circadian Ca²⁺ rhythms were detected in solitary SCN neurons. A relatively large fraction of SCN neurons generates the intrinsic circadian oscillation without neural or humoral networks. Glial cells seem to interrupt the expression of the circadian rhythmicity of intracellular Ca²⁺ under these conditions.