Fig. 3

Analysis of both the Purkinje cell perikaryal and dendritic compartments in FRDA. a 3-dimensional confocal image of a FRDA case depicting a Purkinje cell immunofluorescently labelled with Calbindin-D_28K (green) and DAPI nuclear stain (blue). The hatched areas in (i) represents the higher magnified images (ii; dendritic compartment) and (iii; perikaryal compartment (white arrow)). Quantification of (b) Purkinje cells per mm in FRDA and control cases; (c) Purkinje cell perikaryon cell size categorised into: total Purkinje cells in FRDA (FRDA), Purkinje cells in FRDA with an axon torpedo (FRDA torpedo) and total Purkinje cells in control cases; (d) Purkinje cells with an abnormal perikaryal morphology; and (e) Purkinje cells with SMI-34 positive perikarya. f, (i) Purkinje cell with a normal perikaryon morphology (white triangle) and a Purkinje cell with an axon torpedo presenting with an abnormal (deflated and shrunken appearance) perikaryal morphology (white arrow). The hatched areas in (i) represents the higher magnified images (ii) and (iii) showing the shrunken Purkinje cell with axonal (white arrow) and perikaryal/dendritic SMI-34 accumulation (white triangles). g A representative image depicting how changes in dendritic arborisation were investigated. Concentric quarter circles (with increasing diameter of 20 μm) were aligned on the centre of each Purkinje cell perikaryon and the number of times each circle transected a dendrite was counted. The number of transections per mm at each distance was calculated. The hatched areas in (i) represents the higher magnified image (ii). h Quantification of the number of dendritic transections per mm at increasing distances from the cell perikaryon in FRDA and control cases. Results are expressed as the mean +/- (SE) (**p < 0.01, *p < 0.05, ns (not significant), comparing FRDA to control)