Fig. 6. Morphological effects of TrkB signaling perturbations on Purkinje cell dendritic spines.A–C, Maximum and minimum head diameter and neck length are shown for spines with heads. Treatment with TrkB-IgG leads to a significant increase in neck length in all three experiments. D, Length of filopodia-like spines. Schematic indicates the parameters measured (A–D) for headed (1) and filopodial (2) spines. Number of dendritic spines measured for each bar:A–C, Experiment 1:control, n = 77;BDNF, n = 56;TrkB-IgG, n = 70;Experiment 2: control,n = 86; BDNF, n= 129; TrkB-IgG, n = 78; Experiment 3: control,n = 74; BDNF, n= 116; TrkB-IgG, n = 77. D, Experiment 1:control, n = 69;BDNF, n = 63;TrkB-IgG, n = 67;Experiment 2: control,n = 54; BDNF, n= 92; TrkB-IgG, n = 70; Experiment 3: control,n = 56; BDNF, n= 53; TrkB-IgG, n = 44.