Microglia modelling and analysis using L-systems grammar

Medical image analysis requires in the first instance information on the extent of normal variation in a biological system in order to identify pathological changes. MicroMod is an L-systems based software package available through the World Wide Web that allows modelling of complex branching structures such as neurons and glia using deterministic or probabilistic algorithms. In addition, MicroMod includes software for assessing complex structures using methods such as fractal and lacunarity analysis. We demonstrated through fractal analysis of simulated microglia that MicroMod can be used for modelling and measuring different stages of microglial activation. The fractal dimensions of microglia visualised using histochemical techniques showed good agreement with our models made using MicroMod, and changes in complexity and heterogeneity as seen during activation and response to pathology were well emulated by modifying a few essential parameters (sub to parent branch length, sub to parent branch diameter, and sub branch number). These results indicate that MicroMod provides a useful adjunct to neuroscience research into understanding complex changes in structure associated with normal function and disease processes.