Terrestrial hermit crabs of the genus Coenobita display strong behavioral responses to volatile odors and are attracted by chemical cues of various potential food sources. Several aspects of their sense of aerial olfaction have been explored in recent years including behavioral aspects and structure of their peripheral and central olfactory pathway. Here, we use classical histological methods and immunohistochemistry against the neuropeptides orcokinin and allatostatin as well as synaptic proteins and serotonin to provide insights into the functional organization of their primary olfactory centers in the brain, the paired olfactory lobes. Our results show that orcokinin is present in the axons of olfactory sensory neurons, which target the olfactory lobe. Orcokinin is also present in a population of local olfactory interneurons, which may relay lateral inhibition across the array of olfactory glomeruli within the lobes. Extensive lateral connections of the glomeruli were also visualized using the histological silver impregnation method according to Holmes-Blest. This technique also revealed the structural organization of the output pathway of the olfactory system, the olfactory projection neurons, the axons of which target the lateral protocerebrum. Within the lobes, the course of their axons seems to be reorganized in an axon-sorting zone before they exit the system. Together with previous results, we combine our findings into a model on the functional organization of the olfactory system in these animals.

中文翻译：

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寄居蟹 Coenobita clypeatus (Anomala, Coenobitidae) 大脑中初级嗅觉中心的功能形态

Coenobita 属的陆生寄居蟹对挥发性气味表现出强烈的行为反应，并被各种潜在食物来源的化学线索所吸引。近年来已经探索了他们的空中嗅觉的几个方面，包括他们的外围和中枢嗅觉通路的行为方面和结构。在这里，我们对神经肽 orcokinin 和 allatostatin 以及突触蛋白和 5-羟色胺使用经典的组织学方法和免疫组织化学，以深入了解它们在大脑中的主要嗅觉中心的功能组织，即成对的嗅觉叶。我们的结果表明 orcokinin 存在于嗅觉感觉神经元的轴突中，其靶向嗅觉叶。Orcokinin 也存在于局部嗅觉中间神经元群中，这可能会在叶内的嗅觉肾小球阵列中传递侧向抑制。根据 Holmes-Best 的组织学银浸渍法，肾小球的广泛横向连接也被可视化。该技术还揭示了嗅觉系统输出通路的结构组织，即嗅觉投射神经元，其轴突靶向外侧原大脑。在叶内，它们的轴突在离开系统之前似乎在轴突分选区中重组。连同之前的结果，我们将我们的发现结合到这些动物嗅觉系统功能组织的模型中。根据 Holmes-Best 的组织学银浸渍法，肾小球的广泛横向连接也被可视化。该技术还揭示了嗅觉系统输出通路的结构组织，即嗅觉投射神经元，其轴突靶向外侧原大脑。在叶内，它们的轴突在离开系统之前似乎在轴突分选区中重组。连同之前的结果，我们将我们的发现结合到这些动物嗅觉系统功能组织的模型中。根据 Holmes-Best 的组织学银浸渍法，肾小球的广泛横向连接也被可视化。该技术还揭示了嗅觉系统输出通路的结构组织，即嗅觉投射神经元，其轴突靶向外侧原大脑。在叶内，它们的轴突在离开系统之前似乎在轴突分选区中重组。连同之前的结果，我们将我们的发现结合到这些动物嗅觉系统功能组织的模型中。在它们退出系统之前，它们的轴突的进程似乎在轴突分类区重新组织。连同之前的结果，我们将我们的发现结合到这些动物嗅觉系统功能组织的模型中。在它们退出系统之前，它们的轴突的进程似乎在轴突分类区中重组。连同之前的结果，我们将我们的发现结合到这些动物嗅觉系统功能组织的模型中。