Emergence of Periodic Oscillations in Abiotic Proteinoid–Neurotransmitter Assemblies

Abstract

We demonstrate that simple chemical assemblies, such as thermally polymerized amino acids combined with dopamine, can generate spontaneous electrical oscillations that persist for days without requiring genetic programming or evolved molecular machinery. These dopamine-proteinoid systems exhibit burst-like electrical activity resembling action potentials, along with memory effects and complex temporal patterns analogous to early neural dynamics. Using electrochemical impedance spectroscopy and nonlinear dynamics analysis, we monitored eight independent channels over a period of 53 h. Spiking activity varied widely across channels, with between 1 and 248 events per channel and interspike intervals ranging from 521 to 119,238 s. Power-law scaling was consistently observed, indicating behavior consistent with, but not conclusively demonstrating, long-range temporal correlations. Vesicular compartmentalization led to the formation of protocell-like structures, while electrochemical stability was enhanced, with a 60–84% increase in charge storage capacity relative to pure proteinoid systems. Temporal organization spanned multiple timescales, from seconds to hours, revealing structured patterns suggestive of primitive memory and state-dependent dynamics. Dopamine catechol–quinone redox cycling, coupled with ion transport through proteinoid membranes, gives rise to deep attractor basins in the electrochemical landscape. These basins correspond to stable states toward which the system repeatedly returns, exhibiting memory-like behavior. Mathematical modeling reveals dynamics consistent with FitzHugh–Nagumo-type excitability while also highlighting the roles of Nernst equilibrium shifts and stochastic resonance. Collectively, these findings suggest that simple polymers and small molecules were capable of oscillating. They could also retain information. They responded dynamically to their environment. These properties may have existed before the emergence of neurons and synapses. They may even have preceded the origin of life itself. This perspective suggests that the transition from chemistry to cognition is not abrupt. Instead, it may be continuous. Matter may gradually acquire properties that are typically associated with living systems.