This is quite an overstatement, the electric potential of a neuron would be most accurately described by some pde, only approximately by the ode's that are usua

This is quite an overstatement, the electric potential of a neuron would be most accurately described by some pde, only approximately by the ode's that are usually used. Then it is another bunch of approximation down the line until you arrive at neural networks. It might be the case that certain types of neural networks accurately model the computational essence of what a brain does, but it does so in quite a different way.