TY - JOUR TI - Shore crabs reveal novel evolutionary attributes of the mushroom body AU - Strausfeld, Nicholas AU - Sayre, Marcel E A2 - Calabrese, Ronald L A2 - Farris, Sarah A2 - Martinez Serra, Pedro A2 - Derby, Charles VL - 10 PY - 2021 DA - 2021/02/09 SP - e65167 C1 - eLife 2021;10:e65167 DO - 10.7554/eLife.65167 UR - https://doi.org/10.7554/eLife.65167 AB - 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 Hemigrapsus nudus, 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. KW - crustacea KW - Malacostraca KW - Hemigrapsus nudus KW - learning KW - memory KW - mushroom body KW - evolution JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -