Figure 1

Glutamate and DVGluT immunoreactivities in the Drosophila mushroom bodies after adult eclosion. (A1, A2) DC0 marks the whole MB neuropil that consists of the calyx (ca) and pedunculus (ped), and the vertical (α, α') and horizontal (β, β' and γ) lobes. The spur (sp) area of the pedunculus contains axons of the γ lobe. (A3) Schemes of the adult MB just before eclosion. The last born KCs extend axons in the cores of the α and β lobes (αc, βc). Arrow indicates the position of a transverse section of the pedunculus on the right showing the layered and concentric organization of the KC axons. (B, C) Frontal sections of the MB lobes labeled with anti-Glu antibodies. One hour after adult eclosion, Glu can be detected at a high level in the lobes but only in the αc and βc axons. Upper insert in (B) shows a transverse section of the pedunculus with strong Glu staining in the α/βc KCs. The lower insert is the control for Glu immunostaining after preabsorption of the diluted antibodies with 10^-4 M conjugated Glu. (D1, D2) In 10-day-old flies, Glu immunoreactivity (green) is absent from the DC0-stained KCs (magenta). Glu is distributed at this stage in scattered patterns in the α and γ lobes and in the spur (sp), and likely originates from MB extrinsic neurons. (E-J) DVGluT immunoreactivity in the MB within 1 hour after after eclosion. Confocal optical sections from the frontal to the posterior parts of the protocerebrum from 201Y-GAL4; UAS-mCD8::GFP flies. Note that the intrinsic α/βc KCs are not positive for DVGluT. Stained processes from extrinsic neurons are found in the α and γ lobes and in the spur (sp) region. Scale bars: 20 μm.