Interneurons involved in mediation and modulation of gill-withdrawal reflex in Aplysia. IV. Morphological basis of presynaptic facilitation.
Interneurons involved in mediation and modulation of gill-withdrawal reflex in Aplysia. IV. Morphological basis of presynaptic facilitation.
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中间神经元参与海兔退鳃反射的介导和调节。
DOI：
10.1152/jn.1981.45.2.340
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发表时间：
1981
影响因子：
2.5
通讯作者：
Kandel,ER
中科院分区：
文献类型：
--
作者：
Bailey,CH;Hawkins,RD;Chen,MC;Kandel,ER
3. 双标记技术揭示了 L29 的神经纤维突起和机械感受器感觉神经元之间的几种直接接触。最常见的接触位点发生在两个神经元的含有囊泡的轮廓之间。尽管在双标记并置中尚未观察到明确的活性区，但其精细结构的各个方面和来自单标记材料的证据表明，感觉神经元突触的调节 L29 可能以活性区为特征。 4. 一些早期研究表明，L29 使用血清素作为递质。为了进一步探讨这种可能性，我们将 L29 的结构与 ApZ~~ ica（元脑细胞）中已知的血清素能神经元的结构进行了比较 (39, 40)。我们发现L29在四个方面与元脑细胞相似：a）致密核心颗粒的存在，b）突触静脉曲张内囊泡的相对形态和区域分布，c）优先在终末期溶酶体内包装体内注射的[3H]血清素的能力，以及a）非典型轴体接触的形成。这些形态上的相似性强化了 L29 调节神经元可能具有血清素能的观点。
3. Double-label techniques have revealed several direct contacts between the neuropil processes of L29 and mechanoreceptor sensory neurons. The most frequent locus of contact occurs between vesicle-containing profiles of both neurons. Although unequivocal active zones have not yet been observed at double-label appositions, aspects of their fine structure and evidence from single-labeled material suggest the modulatory L29 to sensory neuron synapse may be characterized by an active zone. 4. Several earlier studies have suggested that L29 uses serotonin as a transmitter. To explore further this possibility we have compared the structure of L29 to that of a known serotonergic neuron in ApZ~~ ica, the metacerebral cell (39, 40). We have found that L29 resembles the metacerebral cell in four ways: a) the presence of dense core granules, b) the relative morphology and regional distribution of vesicles within synaptic varicosities, c) the ability to package intrasomatitally injected [3H] serotonin preferentially within end-stage lysosomes, and a) the formation of atypical axosomatic contacts. These morphological similarities strengthen the notion that the L29 modulatory neurons may be serotonergic.