The Brian code for the paper: Tan AY, Andoni S, Priebe NJ (2013) A spontaneous state of weakly correlated synaptic excitation and inhibition in visual cortex. Neuroscience 247:364-75 is supplied in this archive. Brian is freely available from http://briansimulator.org After installing Brian run with a command like python TanAndoniPriebe2013_BrianCode.py Alternatively, the code can be easily run in Spyder, a user-friendly interface for Python. Spyder is freely available from http://code.google.com/p/spyderlib/ After installing Brian and Spyder run by opening the code in Spyder, then press the F5 key.