کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5530522 | 1549312 | 2017 | 7 صفحه PDF | دانلود رایگان |
- Tornado-FLIM of OGB-1 in traced axons enables presynaptic [Ca2+] readout in situ.
- Tracing iGluSnFr-expressing axons unveils quantal glutamate release in situ.
- Two methods combined could provide a qualitative leap in neuroscience research.
Brain function relies in large part on Ca2+-dependent release of the excitatory neurotransmitter glutamate from neuronal axons. Establishing the causal relationship between presynaptic Ca2+ dynamics and probabilistic glutamate release is therefore a fundamental quest across neurosciences. Its progress, however, has hitherto depended primarily on the exploration of either cultured nerve cells or giant central synapses accessible to direct experimental probing in situ. Here we show that combining patch-clamp with time-resolved imaging of Ca2+ âsensitive fluorescence lifetime of Oregon Green BAPTA-1 (Tornado-FLIM) enables readout of single spike-evoked presynaptic Ca2+ concentration dynamics, with nanomolar sensitivity, in individual neuronal axons in acute brain slices. In parallel, intensity Tornado imaging of a locally expressed extracellular optical glutamate sensor iGluSnFr provides direct monitoring of single-quantum, single-synapse glutamate releases in situ. These two methods pave the way for simultaneous registration of presynaptic Ca2+ dynamics and transmitter release in an intact brain at the level of individual synapses.
Journal: Cell Calcium - Volume 64, June 2017, Pages 102-108