Fig. 3.

Oligodendroglial cells proliferate in response to demyelination and PDGF. Immunofluorescence for PCNA (green (A)) shows actively proliferating cells in a demyelinated slice, a subset of which are Olig2-positive oligodendroglial cells (red (B)), with merge in (C). Scale bar — 10 μm. D) The number of cells proliferating in cerebellum/brainstem slice cultures, as defined by immunoreactivity against PCNA, increased from 10 DIV (myelination — M), to 12 DIV (demyelination — DM — one day after LPC) and then subsided by 25 DIV (remyelination — RM). E) A subset of these proliferating cells is oligodendroglial cells. Cells double positive for Olig2 and PCNA similarly increased in number from 10 DIV (myelination — M), to 12 DIV (demyelination — DM — one day after LPC) and then subsided by 25 DIV (remyelination — RM). (Mean + S.D., *p < 0.001, ANOVA and Dunnett's Multiple Comparison Test. Unit area = 100,000 μm².) F) Addition of PDGF (10 ng/ml) to the culture medium increased the proliferation of OPCs as assessed by BRDU incorporation (white). (Scale bar 100 μm). G) There is an increase in proliferation of OPCs in slices after addition of PDGF, at each stage, compared to control, as measured by BRDU incorporation at 10 DIV (myelination — M), 12 DIV (demyelination — DM — one day after LPC) and 25 DIV (remyelination — RM) (Mean + S.D., comparisons with control at each time-point. **p < 0.01, *p < 0.05, ANOVA and Dunnett's Multiple Comparison Test. N = 2 experiments. Unit area = 1 mm²).