Fractal analysis to assess the differentiation state of oligodendroglia in culture.

Background: Oligodendroglial development is accompanied by increased cell complexity. A simple and cost-effective evaluation of the pro-myelinating activity of different drugs and/or treatments would be of great interest. In cultured oligodendroglia, an evaluation of the pro-myelinating activity of different drugs and/or treatments can be achieved through fractal analysis, which allows measuring cell complexity.

New Method: Fractal dimension was assessed in two O4 cell types (neural stem cell-derived and lineage-converted adipose tissue mesenchymal cells) under proliferating or differentiating conditions.

Comparison With Existing Methods: This analysis, which was originally developed to analyze microglia, assigns a quantitative value (fractal dimension) to cellular profiles, obtaining higher coefficients as cells increase in size and arborizations instead of mRNA or protein quantification of mature oligodendroglial markers, such as MBP, MAG, O1 or PLP1/DM20.

Results: This article describes a methodology to perform fractal analysis in immunofluorescent images of O4-positive (O4) oligodendroglia using the FracLac plugin of ImageJ software. Pro-myelinating drug Benztropine-treated O4 cells exhibit higher fractal dimension than control group.

Conclusions: The results demonstrated the effectiveness and sensitivity of the fractal dimension coefficient provided by FracLac software to assess the effects of treatments on oligodendroglial differentiation.