Contribution of the spontaneous calcium rhythm to the state of the striatal network

Ca2+是一种通用的信号转导分子。为了表征纹状体细胞中的Ca2+信号，在切片制备中检测了自发的Ca2+节律。在纹状体的神经元和星形胶质细胞中，发现了自发的缓慢而持久的细胞内Ca2+节律，持续时间长达200秒。细胞内Ca2+储存的消耗和IP3受体的阻断降低了Ca2+节律的瞬时速率，mGluR5拮抗剂阻断了神经元和星形胶质细胞中的Ca2+节律。因此，mGluR5-IP3信号级联是神经元和星形胶质细胞中Ca2+节律的主要贡献者。Ca2+节律具有多细胞同步性，神经元和星形胶质细胞都参与同步活动。因此，Ca2+节律可能参与纹状体中神经元-胶质细胞的相互作用。在模拟研究中，我们发现Ca2+节律可以通过Ca2+激活的K+通道调节中棘投射神经元的放电特性。

Ca2+ is a universal signal transduction molecule. To characterize Ca2+ signaling in striatal cells, spontaneous Ca2+ rhythms were examined in slice preparations. In both neurons and astrocytes of the striatum, spontaneous slow and long-lasting intracellular Ca2+ rhythms, which lasted up to 200 s, were found. Depletion of the intracellular Ca2+ store and the blockade of IP3 receptors reduced the transient rate of the Ca2+ rhythm, and an mGluR5 antagonist blocked the Ca2+ rhythms in both neurons and astrocytes. Thus, the mGluR5-IP3 signal cascade is the primary contributor to the Ca2+ rhythm in both neurons and astrocytes. The Ca2+ rhythm features multicellular synchrony, and both neurons and astrocytes participate in the synchronous activity. Therefore, the Ca2+ rhythm may involve in the neuron-glia interaction in the striatum. In the simulation study, we found that the Ca2+ rhythm can modulate the firing properties of the medium spiny projection neurons via Ca2+-activated K+ channels.