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

钙离子是一种普遍存在的信号转导分子。为了研究纹状体细胞中的钙信号，在切片制备中检测了自发的钙节律。纹状体内神经元和星形胶质细胞均出现自发性的缓慢而持久的细胞内钙节律，这种节律可持续到S。细胞内钙储备库的耗竭和IP3受体的阻断降低了钙节律的瞬时频率，mGluR5拮抗剂阻断了神经元和星形胶质细胞的钙节律。因此，mGluR5-IP3信号级联是神经元和星形胶质细胞钙节律的主要贡献者。钙节律具有多细胞同步性，神经元和星形胶质细胞均参与同步活动。因此，Ca~(2+)节律可能参与了纹状体神经元-胶质细胞的相互作用。在模拟研究中，我们发现钙节律可以通过钙激活的K+通道来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.