N- and P/Q-type Ca2+ channels regulate synaptic efficacy between spinal dorsolateral funiculus terminals and motoneurons.
N- and P/Q-type Ca2+ channels regulate synaptic efficacy between spinal dorsolateral funiculus terminals and motoneurons.
复制标题
N 型和 P/Q 型 Ca2 通道调节脊髓背外侧索末端和运动神经元之间的突触功效。
DOI：
10.1016/j.bbrc.2004.03.080
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发表时间：
2004
影响因子：
3.1
通讯作者：
R. Delgado
中科院分区：
文献类型：
--
作者：
J. Aguilar;Lourdes Escobedo;Wendy Bautista;R. Felix;R. Delgado
通过电压门控Ca 2+通道的Ca 2+内流介导许多中枢突触的突触传递。然而，电生理和药理学证据表明，在脊椎动物成熟的脊髓钙通道活性与神经递质的释放是稀缺的。在目前的报告中，我们研究了从成年海龟脊髓切片制备，各种钙离子通道拮抗剂对神经传递的影响，从背外侧索突触运动神经元的终端。河豚毒素或NiCl 2的浴应用阻止单突触兴奋性突触后电位（EPSPs），这种效果被暴露于零钙溶液模拟。应用阻断N型和P/Q型通道的多肽毒素（ω-CTx-GVIA和ω-Aga-IVA）以剂量依赖性方式降低EPSP振幅。通过分析输入电阻和EPSP的时间过程，并使用配对脉冲协议，我们确定，这两种毒素的行为在突触前水平，以调节神经递质的释放。RT-PCR研究表明，在海龟脊髓中的N-和P/Q-型通道的mRNA的表达。总之，这些结果表明，N-和P/Q-型Ca 2+通道可能在成年海龟脊髓神经递质释放的调节中发挥核心作用。
Ca2+influx through voltage-gated Ca2+channels mediates synaptic transmission at numerous central synapses. However, electrophysiological and pharmacological evidence linking Ca2+channel activity with neurotransmitter release in the vertebrate mature spinal cord is scarce. In the current report, we investigated in a slice preparation from the adult turtle spinal cord, the effects of various Ca2+channel antagonists on neurotransmission at terminals from the dorsolateral funiculus synapsing motoneurons. Bath application of tetrodotoxin or NiCl2prevented the monosynaptic excitatory postsynaptic potentials (EPSPs), and this effect was mimicked by exposure to a zero-Ca2+solution. Application of polypeptide toxins that block N- and P/Q-type channels (ω-CTx-GVIA and ω-Aga-IVA) reduced the EPSP amplitude in a dose-dependent manner. By analyzing the input resistance and the EPSP time course, and using a paired pulse protocol we determined that both toxins act at presynaptic level to modulate neurotransmitter release. RT-PCR studies showed the expression of N- and P/Q-type channel mRNAs in the turtle spinal cord. Together, these results indicate that N- and P/Q-type Ca2+channels may play a central role in the regulation of neurotransmitter release in the adult turtle spinal cord.
由 α 1A 亚基编码的神经元钙通道及其对中枢神经系统兴奋性突触传递的贡献。
影响因子：
--
作者：
Wheeler,DB;Randall,A;Sather,WA;Tsien,RW
通讯作者：
Tsien,RW