α-latrotoxin (α-LTX), a neurotoxin from black-widow spider, causes vesicles release in pre- synapse of nerve terminal after binding to specific membrane receptors. α-LTXN4C is an effective tool binding to calcium i...α-latrotoxin (α-LTX), a neurotoxin from black-widow spider, causes vesicles release in pre- synapse of nerve terminal after binding to specific membrane receptors. α-LTXN4C is an effective tool binding to calcium independent receptor for latrotoxin (CIRL), which is used to elucidate the mechanism of receptor-mediated signal pathway. In our study on the pancreatic β cells, we found that α-LTX inserts into the plasma membrane and forms stable non-selective cation channels. The influx of ex- tracellular Ca2+ through the channels causes massive Ca2+-dependent exocytosis of insulin-containing vesicles, whereas, α-LTXN4C, binding with its receptor CIRL in extracellular divalent cation-dependent way, increases [Ca2+]i by mobilization of the intracellular calcium stores.展开更多
The development of synapses is an important question in neurobiology. We employ patchclamp technique to record MEPCs and EPCs of myoballs in Xenopus cell culture. The rate of EPC/MEPC is related with synapses maturati...The development of synapses is an important question in neurobiology. We employ patchclamp technique to record MEPCs and EPCs of myoballs in Xenopus cell culture. The rate of EPC/MEPC is related with synapses maturation. Accordingly, we define the mature synapses as those whose rate of presynaptic membrane’s EPC to MEPC is more than 8. The process of maturation needs about 2-5 h after neurites contact with myoballs. We divide the development of synapses into three stages: young, developing and mature. The neurotransmitters stack gradually and increase by hundreds of times along with young synapses growing into maturity. So the process of synapses maturation should include presynaptic membrane specialization, postsynaptic membrane specialization and neurotransmitters stack.展开更多
基金We thank Prof.Yuri Ushkaryov for supplying α-LTXN4C.This work was supported by the National Natural Science Foundation of China(Grant Nos.30270363&30130230)the National Basic Research Program of China(Grant Nos.G1999054000&2004CB720000).
文摘α-latrotoxin (α-LTX), a neurotoxin from black-widow spider, causes vesicles release in pre- synapse of nerve terminal after binding to specific membrane receptors. α-LTXN4C is an effective tool binding to calcium independent receptor for latrotoxin (CIRL), which is used to elucidate the mechanism of receptor-mediated signal pathway. In our study on the pancreatic β cells, we found that α-LTX inserts into the plasma membrane and forms stable non-selective cation channels. The influx of ex- tracellular Ca2+ through the channels causes massive Ca2+-dependent exocytosis of insulin-containing vesicles, whereas, α-LTXN4C, binding with its receptor CIRL in extracellular divalent cation-dependent way, increases [Ca2+]i by mobilization of the intracellular calcium stores.
文摘The development of synapses is an important question in neurobiology. We employ patchclamp technique to record MEPCs and EPCs of myoballs in Xenopus cell culture. The rate of EPC/MEPC is related with synapses maturation. Accordingly, we define the mature synapses as those whose rate of presynaptic membrane’s EPC to MEPC is more than 8. The process of maturation needs about 2-5 h after neurites contact with myoballs. We divide the development of synapses into three stages: young, developing and mature. The neurotransmitters stack gradually and increase by hundreds of times along with young synapses growing into maturity. So the process of synapses maturation should include presynaptic membrane specialization, postsynaptic membrane specialization and neurotransmitters stack.
