Cell-free action potentials as a dynamical system*

Action potentials, voltage spikes in the neuron, play an essential role in biological communication.  This unique analog/digital dynamical system has been the subject of extensive study, yet until recently action potentials have not been generated outside the living cell.  By constructing a dressed down system using only the essential biological components (lipid membrane, voltage gated ion channels, and an ionic gradient), we are able to generate and regulate action potentials in vitro.  The system is modeled using a mean field approach to explore the available types of behavior within the phase space.  These simulated results are used to guide our experimental implementation, and we demonstrate that our artificial excitable system is capable of producing much of the same dynamics as measured in real neurons.