Biologically detailed data-driven models of individual neurons, neuron microcircuits and functional neural networks are developed. The goal of the study is to achieve realism of simulated electro-physiological behavior of the target brain structures, mainly the basal ganglia and associated areas, as well as the brainstem control centers and spinal locomotor networks. Models of the neural circuits and their building blocks are optimized and validated to match the available experimental data. The work is performed in collaboration between research groups in CST EECS KTH and Dept. of Neuroscience KI.