Fig. 4. Dendritic defects caused by overexpression of Fmr1 in DA neurons of wild-type larvae. (A) Ventral DA neurons in each hemisegment elaborate their dendrites underneath the ventral epidermis. The dendritic field near the cell bodies of ventral cluster DA neurons in a wild-type larva is shown. (B) Overexpression of Fmr1 in ventral DA neurons reduced the number of dendritic processes. (C) All dendritic processes in a specific area in the A5 segment were counted, and the average numbers for wild-type and Fmr1 mutant larvae are presented (n=25, ***P<0.001). (D) Dorsal cluster DA neurons in the A5 segment of a wild-type larva elaborated higher-order dendritic processes near the dorsal midline. (E) Fmr1 overexpression reduced the number of terminal dendritic processes near the dorsal midline. Scale bars: 40 µm. The arrows in D,E indicate the dorsal midline.