1. A neuron for use in a self-learning neural network comprising, an input node for summing a plurality of bi-directional synaptic input currents to obtain a summed bi-directional input current, a current normalizer for normalizing said summed input current to obtain a normalized summed input current, a current to voltage converter for converting the normalized summed input current into a bi-directional voltage representative of the normalized summed bi-directional input current, and an output amplifier having a gain for generating bi-directional output voltage in response to said voltage representative of said normalized summed input current.