Department of Pharmacology & Neuroscience, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX 76107, USA.
Adv Exp Med Biol. 2012;740:603-38. doi: 10.1007/978-94-007-2888-2_27.
The spatiotemporal distribution of cytosolic Ca(2+) ions is a key determinant of neuronal behavior and survival. Distinct sources of Ca(2+) ions including ligand- and voltage-gated Ca(2+) channels contribute to intracellular Ca(2+) homeostasis. Many normal physiological and therapeutic neuronal functions are Ca(2+)-dependent, however an excess of cytosolic Ca(2+) or a lack of the appropriate balance between Ca(2+) entry and clearance may destroy cellular integrity and cause cellular death. Therefore, the existence of optimal spatiotemporal patterns of cytosolic Ca(2+) elevations and thus, optimal activation of ligand- and voltage-gated Ca(2+) ion channels are postulated to benefit neuronal function and survival. Alpha7 nicotinic -acetylcholine receptors (nAChRs) are highly permeable to Ca(2+) ions and play an important role in modulation of neurotransmitter release, gene expression and neuroprotection in a variety of neuronal and non-neuronal cells. In this review, the focus is placed on α7 nAChR-mediated currents and Ca(2+) influx and how this source of Ca(2+) entry compares to NMDA receptors in supporting cytosolic Ca(2+) homeostasis, neuronal function and survival.
细胞浆钙离子的时空分布是神经元行为和存活的关键决定因素。包括配体门控和电压门控钙离子通道在内的不同钙离子来源有助于细胞内钙离子的动态平衡。许多正常的生理和治疗性神经元功能都依赖钙离子,然而,细胞浆钙离子过多或钙离子进入和清除之间的平衡失调,可能会破坏细胞的完整性并导致细胞死亡。因此,推测细胞浆钙离子浓度升高的最佳时空模式的存在,以及配体门控和电压门控钙离子通道的最佳激活,将有利于神经元的功能和存活。α7 型烟碱型乙酰胆碱受体(nAChRs)对钙离子具有高通透性,在各种神经元和非神经元细胞中,对神经递质释放、基因表达和神经保护的调节起着重要作用。在这篇综述中,重点介绍了 α7 nAChR 介导的电流和钙离子内流,以及这种钙离子进入源在支持细胞浆钙离子动态平衡、神经元功能和存活方面与 NMDA 受体的比较。