Abstract
Environmental perturbations and local changes in cellular electric potential can stimulate cytoskeletal filaments to transmit ionic currents along their surface. Advanced models and accurate experiments may provide a molecular understanding of these processes and reveal their role in cell electrical activities. This article introduces a multi-scale electrokinetic model incorporating atomistic protein details and biological environments to characterize electrical impulses along microtubules. We consider that condensed ionic layers on microtubule surfaces form two coupled asymmetric nonlinear electrical transmission lines. The model accounts for tubulin-tubulin interactions, dissipation, and a nanopore coupling between inner and outer surfaces, enabling luminal currents, energy transfer, amplification, and oscillatory dynamics that resemble the experimentally observed transistor properties of microtubules. The approach has been used to analyze how different electrolyte conditions and voltage stimuli affect electrical impulses' shape, attenuation, oscillation, and propagation velocity along microtubules. Integrating transistor-like properties in the microtubules model has profound implications for intracellular communication and bioelectronic applications.