A spike domain circuit responsive to analog and/or spike domain input signals. The spike domain circuit has a hysteresis quantizer for generating a spike domain output signal z(t); a one bit DAC having an input which is coupled to receive the spike domain output signal z(t) output by the hysteresis quantizer and having an output which is coupled to a current summing node; and a second order filter stage having two inputs, one of said two inputs being coupled to receive the spike domain output signal z(t) output by the hysteresis quantizer and the other of the two inputs being coupled to receive current summed at said current summing node. The second order filter stage has an output coupled to an input of the hysteresis quantizer. The current summing node also receives signals related to the analog and/or spike domain input signals to which the circuit is responsive. The circuit may serve as a neural node and many such circuits may be utilized together to model neurons with complex biological dynamics.