Optimizing synaptic architecture and efficiency for high-frequency transmission
Optimizing synaptic architecture and efficiency for high-frequency transmission
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DOI：
10.1016/s0896-6273(02)01137-6
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发表时间：
2002-12-19
期刊：
影响因子：
16.2
通讯作者：
von Gersdorff, H
中科院分区：
文献类型：
--
作者：
Taschenberger, H;Leao, RM;von Gersdorff, H
神经元活动的爆发随着突触的成熟而更有效地传递。然而，在发育过程中控制突触效率的机制知之甚少。在这里，我们研究突触超微结构和胞吐作用在一个花萼型神经末梢出生后的变化。囊泡池的大小，胞吐效率（每钙内流的胞吐量），钙电流促进，和活跃区（AZ）的数量随年龄的增加，而AZ面积，停靠囊泡每AZ的数量，和释放概率随年龄的增长而下降。这些变化导致AZ不太倾向于多泡释放，导致AMPA受体饱和度降低和脱敏。因此，具有较少停靠囊泡的小AZ的更大多样性、更大的可释放囊泡池和更高的释放效率促进了成熟突触中长时间的高频放电。
Bursts of neuronal activity are transmitted more effectively as synapses mature. However, the mechanisms that control synaptic efficiency during development are poorly understood. Here, we study postnatal changes in synaptic ultrastructure and exocytosis in a calyx-type nerve terminal. Vesicle pool size, exocytotic efficiency (amount of exocytosis per Ca influx), Ca current facilitation, and the number of active zones (AZs) increased with age, whereas AZ area, number of docked vesicles per AZ, and release probability decreased with age. These changes led to AZs that are less prone to multivesicular release, resulting in reduced AMPA receptor saturation and desensitization. A greater multiplicity of small AZs with few docked vesicles, a larger pool of releasable vesicles, and a higher efficiency of release thus promote prolonged high-frequency firing in mature synapses.