کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9425487 | 1295876 | 2005 | 12 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Synapse-to-synapse variation of calcium channel subtype contributions in large mossy fiber terminals of mouse hippocampus
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کلمات کلیدی
aCSFOGB-1VDCCpresynapticGCLω-agatoxin IVA - ω-آگاتوکسین IVAω-conotoxin GVIA - ω-کنوتوکسین GVIAcornu ammonis - بال آمونCalcium imaging - تصویر برداری کلسیمیnetwork - شبکهdentate gyrus - شکنج دندانه دارCoefficient of Variation - ضریب تغییرmossy fiber - فیبر قارچBrain slice - قطعه مغزgranule cell layer - لایه سلول گرانولmolecular layer - لایه مولکولیartificial cerebrospinal fluid - مایع مغزی نخاعی مصنوعیVoltage-dependent calcium channel - کانال کلسیم وابسته به ولتاژLearning and memory - یادگیری و حافظه
موضوعات مرتبط
علوم زیستی و بیوفناوری
علم عصب شناسی
علوم اعصاب (عمومی)
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Both N- and P/Q-type voltage-dependent calcium channels are involved in fast transmitter release in the hippocampus, but are differentially regulated. Although variable contributions of voltage-dependent calcium channel subtypes to presynaptic Ca2+ influx have been suggested to give a neural network of great diversity, their presence has only been demonstrated in a culture system and has remained unclear in the brain. Here, the individual large mossy fiber presynaptic terminal was labeled with Ca2+/Sr2+-sensitive fluorescent dextrans in the hippocampal slice of the mouse. The fractional contribution of voltage-dependent calcium channel subtypes to presynaptic Ca2+/Sr2+ influx was directly measured by the sensitivity of Ca2+/Sr2+-dependent fluorescent increment to subtype-selective neurotoxins, Ï-conotoxin GVIA (an N-type selective blocker), Ï-agatoxin IVA (a P/Q-type selective blocker) and SNX-482 (an R-type selective blocker). Synapse-to-synapse comparison of large mossy fiber terminals revealed that the contributions of N- and R-type voltage-dependent calcium channels varied more widely than that of P/Q-type. Even two large mossy fiber presynaptic terminals neighboring on the same axon differed in the fractional contributions of N- and R-type voltage-dependent calcium channels. On the other hand, these terminals were similar in the fractional contributions of P/Q-type voltage-dependent calcium channels. These results provide direct evidence that individual large mossy fiber synapses are differential in the contribution of N- and R-type voltage-dependent calcium channel subtypes to presynaptic Ca2+/Sr2+ influx. We suggest that the synapse-to-synapse variation of presynaptic voltage-dependent calcium channel subtype contributions may be one of the mechanisms amplifying diversity of the hippocampal network.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Neuroscience - Volume 136, Issue 4, 2005, Pages 1003-1014
Journal: Neuroscience - Volume 136, Issue 4, 2005, Pages 1003-1014
نویسندگان
K. Miyazaki, T. Ishizuka, H. Yawo,