Adf-1 is required for activity-dependent change in dendrite growth. A, Representative RP2 dendrite reconstructions to test the interaction between Adf-1 and changes in neuronal activity. B, C, Volumetric Sholl analysis and the measurement of dendrite branch number and length following an increase in neural activity and Adf-1 inhibition. D, E, Volumetric Sholl analysis and measurement of dendrite branch number and length following neuronal silencing and Adf-1 activation. Adf-1[S64/184D] increases both dendrite number and length in an activity silenced background (*p < 0.05 for pairwise comparison after Bonferroni's correction). **p < 0.01. F, G, Branch-order analysis in experiments that test Adf-1 function downstream of activity manipulations in RP2 motor neurons.