Fig. 2
From: Structural aspects of plasticity in the nervous system of Drosophila
Visual system and olfactory circuit in the adult fly brain. a Dorsal view of the adult Drosophila head and schematic drawing of major brain centers, including the visual system and the MB (boxes). b Horizontal section of the visual system including the retina, lamina, medulla, lobula and lobula plate. Representative neuron types cited in this review are shown, including photoreceptors (blue; R1–6, R7 and R8), lamina neurons (orange; L1-L5), medulla neurons (green) and a Lobula plate tangential cell (magenta; LPTC). c Schematic representation of the pathways delivering olfactory information to the MB. Olfactory sensory neurons (OSN) in the antennae and maxillary palps send axons to specific glomeruli in the antennal lobe (AL), where they form synaptic contacts with projection neurons (PNs). PNs convey olfactory sensory input to the lateral horn and to the calyx of the mushroom bodies (MB). In the MB calyx PN axonal projections and MB dendrites create synaptic complexes, named microglomeruli (MG). MB neurons process the olfactory information by integration of signals of anterior paired lateral neuron (APL) and dopaminergic neurons (DANs) to control mushroom body output neurons (MBONs)