Models for Spiking Neurons: Integrate-and-Fire Units and Relaxation Oscillators

Relaxation oscillators are nonlinear electronic circuits that produce a repetitive non-sinusoidal waveform when sufficient voltage is applied. In this fashion, they are reminiscent of integrate-and-fire neuron models, except that they also include components with hysteresis, and thus require no threshold rule to determine when an impulse has occurred or to return the voltage to its reset value. Here, I discuss the pros and cons of teaching elementary neurophysiology using first-order linear integrate-and-fire neurons versus relaxation oscillator circuits. I suggest that the shortcomings of both types of models are useful in order to foster a critical understanding of the neurophysiology underlying the firing dynamics of biological neurons.