Figure 1.

Brian model structure. Brian users define models by specifying equations governing a single neuron or synapse. Simulations consist of an ordered sequence of operations (code blocks) acting on neuronal or synaptic data. A neuronal code block can only modify its own data, whereas a synaptic code block can also modify data from its pre- or post-synaptic neurons. Neurons have three code blocks: one for its continuous evolution (numerical integration), one for checking threshold conditions and emitting spike events, and one for post-spike reset in response to those events. Synapses have three code blocks: two event-based blocks for responding to pre- or postsynaptic spikes (corresponding to forward or backward propagation), and one continuous evolution block. Code blocks can be provided directly, or can be generated from pseudo-code or differential equations.