Department of Neuroscience, University of Arizona, Tucson, United States.
Lund Vision Group, Department of Biology, Lund University, Lund, Sweden.
Elife. 2021 Feb 9;10:e65167. doi: 10.7554/eLife.65167.
Neural organization of mushroom bodies is largely consistent across insects, whereas the ancestral ground pattern diverges broadly across crustacean lineages resulting in successive loss of columns and the acquisition of domed centers retaining ancestral Hebbian-like networks and aminergic connections. We demonstrate here a major departure from this evolutionary trend in Brachyura, the most recent malacostracan lineage. In the shore crab , instead of occupying the rostral surface of the lateral protocerebrum, mushroom body calyces are buried deep within it with their columns extending outwards to an expansive system of gyri on the brain's surface. The organization amongst mushroom body neurons reaches extreme elaboration throughout its constituent neuropils. The calyces, columns, and especially the gyri show DC0 immunoreactivity, an indicator of extensive circuits involved in learning and memory.
蘑菇体的神经组织在昆虫中基本一致，而祖先进化模式在甲壳动物谱系中广泛分歧，导致柱的连续丢失和穹顶中心的获得，保留了祖先进化的赫布型网络和胺能连接。在这里，我们展示了短尾类动物（最接近软甲纲的谱系）中这一进化趋势的一个主要偏离。在岸蟹中，蘑菇体的杯状体没有占据侧前脑的额表面，而是深深地埋藏在其中，其柱向外延伸到大脑表面广阔的脑回系统。蘑菇体神经元在其组成的神经丛中达到了极端的复杂化。杯状体、柱体，特别是脑回显示出 DC0 免疫反应性，这是参与学习和记忆的广泛回路的指标。
