Selective fasciculation as a mechanism for the formation of specific chemical connections between Aplysia neurons in vitro.
Selective fasciculation as a mechanism for the formation of specific chemical connections between Aplysia neurons in vitro.
复制标题
选择性束颤作为体外海兔神经元之间形成特定化学连接的机制。
DOI：
10.1002/neu.480240309
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
Schacher,S
中科院分区：
文献类型：
--
作者：
Hawver,DB;Schacher,S
生长锥沿着预先建立的轴突通路选择性成束表达匹配或互补粘附分子被认为是轴突导向的重要策略。生长锥抑制因素似乎也影响寻路决策。我们已经在体外使用了鉴定的曲霉菌来探索类似的机制可能参与靶选择的假设。L10神经元与RB神经元靶标或R2神经元与RUQ神经元靶标的共培养物可靠地形成化学连接。相比之下，L10与RUQ靶标的共培养物通常不能形成可检测的化学连接，除非在铺板期间通过缠绕主要轴突迫使细胞-细胞接触。这些数据表明，形成细胞-细胞接触的能力的差异可能是所观察到的突触特异性的基础。当L10和R2的荧光染料填充显示靶接触量与突触形成频率之间的正相关性时，这一观点得到了支持：L10-RUQ培养物显示出比L10-RB或R2-RUQ培养物少得多的靶接触。为了研究这些差异的细胞机制，在目标接触，突触前生长锥进行了观察，因为它们与目标过程的相互作用。与L10-RB和R2-RUQ培养物相比，L10-RUQ培养物显示出少得多的束颤和更多的回避行为。这种最初的特异性表明，目标接触量的差异是通过选择性肌束震颤和回避产生的，而不是通过不分青红皂白的肌束震颤后的选择性消除产生的。因此，选择性束颤和回避可能通过调节突触前突起和潜在靶细胞之间的接触量来帮助靶选择。John Wiley & Sons，Inc.
Selective fasciculation of growth cones along preestablished axon pathways expressing matching or complementary adhesion molecules is thought to be an important strategy in axon guidance. Growth cone inhibiting factors also appear to influence pathfinding decisions. We have used identifiedAplysianeuronsin vitroto explore the hypothesis that similar mechanisms could be involved in target selection. Co‐cultures of L10 neurons with RB neuron targets or R2 neurons with RUQ neuron targets reliably formed chemical connections. In contrast, co‐cultures of L10 with RUQ targets usually failed to form detectable chemical connections unless cell–cell contact was forced during plating by intertwining the major axons. These data suggested that differences in the ability to form cell–cell contacts might underlie the observed synaptic specificity. This notion was supported when fluorescent dye fills of L10 and R2 revealed a positive correlation between the amount of target contact and the frequency of synapse formation: L10–RUQ cultures showed much less target contact than L10–RB or R2–RUQ cultures. To examine the cellular mechanisms of these differences in target contact, presynaptic growth cones were observed as they interacted with target processes. L10–RUQ cultures showed much less fasciculation and more avoidance behavior compared to L10–RB and R2–RUQ cultures. This initial specificity suggested that the differences in amount of target contact arose through selective fasciculation and avoidance rather than through selective elimination after indiscriminate fasciculation. Selective fasciculation and avoidance might, therefore, aid in target selection by regulating the amount of contact between presynaptic processes and potential target cells. © 1993 John Wiley & Sons, Inc.