Synapses

• Neurons connect to other neurons by uni-directional synapses.
• The simple way to model these is with weights. They can be excitatory or inhibitory.
• The mode we typically use passes all the current from the pre-synaptic neuron to the post-synaptic neuron in the next cycle.
• Lots of modelling is focussed on this, and there are much more complex regimes.
• This raises the issue of time.
• One could simulate this all in real time.
• The CANT simulations assume 10ms time steps.
• The HBP systems (particularly the neuromorphic ones) assume a 1ms time step.
• There are also issues with neurons with refractory periods; neurons won't fire immediately after they fire.