Prominent lobed neuropils found in annelids and all arthropods except crustaceans. They are thought to be involved in olfactory associative learning and memory[MESH] Mushroom body neuropils are divided into calyces, pedunculus, and its subsequent lobes. In Drosophila these are the alpha, beta, and gamma lobes. [ http://en.wikipedia.org/wiki/Mushroom_body http://flybrain.uni-freiburg.de/Flybrain/html/terms/terms.html MESH:A13.641 ]
Synonyms: mushroom bodies
Also in annelids. 'Comparison to the vertebrate pallium reveals that the annelid mushroom bodies develop from similar molecular coordinates within a conserved overall molecular brain topology and that their development involves conserved patterning mechanisms and produces conserved neuron types that existed already in the proto- stome-deuterostome ancestors. These data indicate deep homology of pallium and mushroom bodies and date back the origin of higher brain centers to prebilaterian times'