Turner T J, Adams M E, Dunlap K
Department of Physiology, Tufts University School of Medicine, Boston, MA 02111.
Science. 1992 Oct 9;258(5080):310-3. doi: 10.1126/science.1357749.
Presynaptic calcium channels are crucial elements of neuronal excitation-secretion coupling. In mammalian brain, they have been difficult to characterize because most presynaptic terminals are too small to probe with electrodes, and available pharmacological tools such as dihydropyridines and omega-conotoxin are largely ineffective. Subsecond measurements of synaptosomal glutamate release have now been used to assess presynaptic calcium channel activity in order to study the action of peptide toxins from the venom of the funnel web spider Agelenopsis aperta, which is known to inhibit dihydropyridine and omega-conotoxin-resistant neuronal calcium currents. A presynaptic calcium channel important in glutamate release is shown to be omega-Aga-IVA sensitive and omega-conotoxin resistant.
突触前钙通道是神经元兴奋-分泌偶联的关键元件。在哺乳动物大脑中，它们一直难以被表征，因为大多数突触前终末太小而无法用电极进行探测，并且诸如二氢吡啶和ω-芋螺毒素等现有的药理学工具在很大程度上无效。现在，已利用对突触体谷氨酸释放的亚秒级测量来评估突触前钙通道活性，以便研究漏斗网蜘蛛（Agelenopsis aperta）毒液中的肽毒素的作用，已知该毒液可抑制对二氢吡啶和ω-芋螺毒素耐药的神经元钙电流。结果表明，在谷氨酸释放中起重要作用的突触前钙通道对ω-Aga-IVA敏感且对ω-芋螺毒素耐药。
