Brain organization in Collembola (springtails)

► We examined three collembolan species and identified several brain structures. ► A fan-shaped central body showing a columnar organization. ► A protocerebral bridge. ► One pair of antennal lobes with 20-30 spheroidal glomeruli each. ► A structure, which we interpret as a simply organized mushroom body. ► The results suggest a phylogenetic position of Collembola within the Hexapoda.