An important discovery that has come out of computational neuroscience, is that cortical neurons in vivo appear to receive so-called balanced inputs.
In the balanced state the excitatory and inhibitory synaptic inputs to a neuron are about equal, and action potentials occur when a fluctuation temporarily makes the excitation dominate.
The theory, for example, explains the observed irregular firing of cortical neurons in the background state.
Today's guest was one of the key developers of the theory in the late 1990s.