The mushroom body has three lobes (left) called α/β (blue), α′/β′ (pink) and γ (green). Each lobe is made up of projections from many Kenyon cells (KC) and is divided into five compartments (shown by the dark outlines). Each compartment (right) is defined by the projections from a limited number of dopaminergic neurons (DANs) and mushroom body output neurons (MBONs). The Kenyon cells carry sparse information about odor, while the dopaminergic neurons signal a reward or a punishment. The MBONs carry information away from the mushroom body to convergence zones in order to alter behavior. The Kenyon cells of each lobe extend through all the compartments of that lobe and form synapses with all the MBONs. However, each compartment contains a unique set of dopaminergic neurons and MBONs: this allows the information about odor to be used by several MBONs and to be modified by multiple types of dopaminergic neurons.