The nervous system encompasses structure and phe- nomena at different spatial and temporal scales. In addi- tion, different scales are described by different physical and mathematical formalisms. In neuroscience, there is an in- creasing need to study phenomena where multiple scales and physical formalisms are covered by a single model. Most models developed thus far are limited to one scale and one type of physical process, but in many cases it would be relatively easy to develop multi-scale and multi-physics models of the nervous system only by integrating existing models. However, the lack of interoperability between dif- ferent simulators has made it difficult to reuse models. This project aims to be a preparatory work towards a frame- work for multi-scale modeling which builds on the concept of multi-simulations. We have built and studied a proto- type model of the electrical activity and calcium dynamics in a dendritic spine using two different simulators, MOOSE and NeuroRD. The combined system and the numerical methods used by both simulators are studied analytically and experimentally in terms of stability and accuracy.
