论文部分内容阅读
小脑颗粒细胞是离体单细胞水平中枢神经元生物学研究的理想模型．随着细胞发育，其ＨＶＡ钙电流的基因表达、门控性质和药理学特征发生明显变化，提示钙电流涉及颗粒细胞的成熟和兴奋性的产生．多巴胺通过激活膜上的Ｄ４受体抑制Ｌ型钙电流，这种抑制效应并不需要腺苷酸环化酶系统的参与．功能性Ｄ４受体的首次发现不仅有助于研究抗精神病药，更揭示了多巴胺也参与小脑神经元之间的兴奋传递过程．ＰＡＣＡＰ则通过激活其Ｉ受体增加钙内流和钙库的释放使胞浆内钙浓度提高，ＰＡＣＡＰ的钙通道刺激效应可能需要ＰＬＣ系统的介导，并与颗粒细胞的成熟和成活有关．
Cerebellar granulosa cells are an ideal model for the biological studies of central neurons at the level of single cells in vitro. As the cells develop, the gene expression, gating properties and pharmacology of the HVA calcium currents change significantly, suggesting that calcium currents are involved in the maturation and excitability of granulosa cells. Dopamine inhibits L-type calcium current by activating the D4 receptor on the membrane. This inhibitory effect does not require the involvement of the adenylate cyclase system. The first discovery of a functional D4 receptor not only helps in the study of antipsychotics, but also reveals that dopamine is also involved in the process of excitatory transmission of cerebellar neurons. PACAP increases intracellular calcium concentration by activating its I receptor to increase calcium influx and release of calcium stores. The calcium channel stimulation effect of PACAP may be mediated by the PLC system and is associated with the maturation and survival of granulosa cells.