期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2003
卷号：100
期号：5
页码：2813-2818
DOI：10.1073/pnas.262787299
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Fast cholinergic neurotransmission between superior cervical ganglion neurons (SCGNs) in cell culture is initiated by N-type Ca2+ currents through Cav2.2 channels. To test the ability of different Ca2+-channel subtypes to initiate synaptic transmission in these cells, SCGNs were injected with cDNAs encoding Cav1.2 channels, which conduct L-type currents, Cav2.1 channels, which conduct P/Q-type Ca2+ currents, and Cav2.3 channels, which conduct R-type Ca2+ currents. Exogenously expressed Cav2.1 channels were localized in nerve terminals, as assessed by immunocytochemistry with subtype-specific antibodies, and these channels effectively initiated synaptic transmission. Injection with cDNA encoding Cav2.3 channels yielded a lower level of presynaptic labeling and synaptic transmission, whereas injection with cDNA encoding Cav1.2 channels resulted in no presynaptic labeling and no synaptic transmission. Our results show that exogenously expressed Ca2+ channels can mediate synaptic transmission in SCGNs and that the specificity of reconstitution of neurotransmission (Cav2.1 > Cav2.3 >> Cav1.2) follows the same order as in neurons in vivo. The specificity of reconstitution of neurotransmission parallels the specificity of trafficking of these Cav channels to nerve terminals.
