Fig. 4

Dendrites of tectal neurons with DSCAM downregulation take tortuous meandering paths. a Tracings of sample neurons transfected with Control or DSCAM MO and imaged 48 h after initial imaging. For the quantification of dendritic pathway turning the 1st and 2nd longest individual branches of reconstructed neurons were measured three-dimensionally (Control MO n = 62 dendrites, DSCAM MO n = 62 dendrites) using the Neuromantic software meandering contraction value which quantifies bends and turns in a scale from 0 to 1. Here, the pathways of the two longest branches for each sample neuron are highlighted in red and blue and their corresponding contraction values are shown. Note that dendrites of neurons with DSCAM MO take abnormal turns within the dendritic arbor. b Individual branches of neurons with DSCAM MO showed a significantly lower contraction value at each imaging time point when compared to controls. c A measurement of the lengths of the 1st and 2nd longest primary branches of each neuron reveal that dendrite branches were significantly longer in neurons with DSCAM MO than in those with Control MO. d The longest branches in neurons with DSCAM MO also bifurcated more than controls as shown by the significant difference in their branch order number. Scale bars: 10 μm in (a). Statistical comparisons are by Student’s t-tests, error bars indicate mean ± SEM. *p ≤ 0.05, **p ≤ 0.005