STEPS is a package for exact stochastic simulation of reaction-diffusion systems in arbitrarily complex 3D geometries. Our core simulation algorithm is an implementation of Gillespie’s SSA, extended to deal with diffusion of molecules over the elements of a 3D tetrahedral mesh.
While it was mainly developed for simulating detailed models of neuronal signaling pathways in dendrites and around synapses, it is a general tool and can be used for studying any biochemical pathway in which spatial gradients and morphology are thought to play a role.
STEPS also supports accurate and efficient computation of local membrane potentials on tetrahedral meshes, with the addition of voltage-gated channels and currents. Tight integration between the reaction-diffusion calculations and the tetrahedral mesh potentials allows detailed coupling between molecular activity and local electrical excitability.
We have implemented STEPS as a set of Python modules, which means STEPS users can use Python scripts to control all aspects of setting up the model, generating a mesh, controlling the simulation and generating and analyzing output. The core computational routines are still implemented as C/C++ extension modules for maximal speed of execution.
STEPS 3.0.0 and above provide early parallel solution for stochastic spatial reaction-diffusion and electric field simulation.
STEPS 3.6.0 and above provide a new set of APIs (API2) to speedup STEPS model development. Models developed with the old API (API1) are still supported.
STEPS 4.0.0 and above provide a distributed solution for stochastic spatial reaction-diffusion and electric field simulation.
STEPS User Manual and API References
Contents:
- 1. Getting Started
- 2. Python interfaces to STEPS
- 3. Well-Mixed Reaction System
- 4. Surface-Volume Reactions
- 5. Diffusion in volumes and on surfaces
- 6. Data recording and analysis
- 7. Multi-state complexes
- 8. Simulating membrane potential
- 9. Parallel simulations
- 10. Simulation visualization
- 11. Stochastic Calcium Burst model with GHK currents
- 12. Distributed mesh simulations
- 13. Original STEPS API guides
- 13.1. Well-Mixed Reaction Systems
- 13.2. Surface-Volume Reactions (Example: IP3 Model)
- 13.3. Simulating Diffusion in Volumes
- 13.4. Simulating Diffusion on Surfaces
- 13.5. Diffusion Boundary
- 13.6. Surface Diffusion Boundary
- 13.7. Simulating Membrane Potential
- 13.8. Stochastic Calcium Burst model with GHK currents
- 13.9. From Serial to Parallel (Parallel TetOpSplit Solver)
- 13.10. Visualization Toolkit
- 13.11. SBML support
- 13.12. Preliminary Functionalities
- 13.13. STEPS for Matlab
- 13.14. STEPS-CUBIT Geometry Preparation Toolkit
- 14. API References
- 15. Customizing STEPS installation