Figure 1.

Mushroom body (MB) γ neurons undergo stereotypic remodeling: at larval stage, MB γ neurons project a single axon that branches to form dendrites (den), a tightly fasciculated axon peduncle (p) that bifurcates to form the dorsal (d) and medial (m) lobes. Cortex glia (yellow) instruct MB axon pruning by secreting the TGF‐β ligand Myoglianin. At 6 h after puparium formation (APF), MB γ dendrites are mostly eliminated and axons begin to undergo defasciculation, allowing the astrocytes (green) to infiltrate the dorsal and medial lobes. The role of the remaining unidentified glia or cortex glia during this and later time points is not known (gray). At 12 h APF, axon fragmentation and blebbing are apparent. At 18 h APF, fragmentation is complete and axonal fragments are being engulfed mainly by astrocytes. At 24 h APF, the MB γ neurons begin to regrow toward the adult targets, forming the adult γ lobe. [Reprinted with permission from Ref 7. Copyright 2014]