SYNAPTIC TARGET CONTACT ENHANCES PRESYNAPTIC CALCIUM INFLUX BY ACTIVATING CAMP-DEPENDENT PROTEIN-KINASE DURING SYNAPTOGENESIS
SYNAPTIC TARGET CONTACT ENHANCES PRESYNAPTIC CALCIUM INFLUX BY ACTIVATING CAMP-DEPENDENT PROTEIN-KINASE DURING SYNAPTOGENESIS
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DOI：
10.1016/0896-6273(93)90055-v
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发表时间：
1993-06-01
期刊：
影响因子：
16.2
通讯作者：
HAYDON, PG
中科院分区：
文献类型：
--
作者：
FUNTE, LR;HAYDON, PG
在细胞培养中，将单个分离的上外侧辐射张肌（supralateral radular tensor，ERF）纤维与来自Helisoma的突触前颊运动神经元19的Fura-2填充的神经突接触。在接触30分钟内，动作电位诱发的钙积累从228 +/- 82 nM可逆地增加到803 +/- 212 nM，该作用被H-7（40-100 μ M）阻断。当颊运动神经元19接触肌肉或与其不形成化学突触的神经元靶点时，钙的积累并没有增加。向培养物中加入pCPTcAMP（500 μ M）可逆地增强钙积累。注射cAMP依赖性蛋白激酶的肽抑制剂IP 20可阻止pCPTcAMP和平滑肌增加钙积累。这些数据表明，突触前肌靶点通过局部激活突触前cAMP依赖性蛋白激酶来逆行调节突触前神经末梢中的钙积累。
Individual dissociated supralateral radular tensor (SLT) muscle fibers were manipulated into contact with fura-2-filled neurites of presynaptic buccal motoneuron 19 from Helisoma in cell culture. Within 30 min of contact, action potential-evoked calcium accumulation was reversibly augmented from 228 +/- 82 nM to 803 +/- 212 nM, an action that was blocked by H-7 (40-100 muM). Calcium accumulation was not augmented when buccal motoneuron 19 contacted muscle or neuronal targets with which it does not form chemical synapses. Addition of pCPTcAMP (500 muM) to cultures reversibly enhanced calcium accumulation. Injection of IP20, a peptide inhibitor of cAMP-dependent protein kinase, prevented pCPTcAMP and SLT muscle from enhancing calcium accumulation. These data demonstrate that SLT muscle target retrogradely regulates calcium accumulation in presynaptic nerve terminals by locally activating presynaptic cAMP-dependent protein kinase.