A Non-Invasive and DNA-free Approach to Upregulate Mammalian Voltage-Gated Calcium Channels and Neuronal Calcium Signaling via Terahertz Stimulation

Mammalian voltage-gated calcium channels (Ca_V) play critical roles in cardiac excitability, synaptic transmission, and gene transcription. Dysfunctions in Ca_V are implicated in a variety of cardiac and neurodevelopmental disorders. Current pharmacological approaches to enhance Ca_V activity are limited by off-target effects, drug metabolism issues, cytotoxicity, and imprecise modulation. Additionally, genetically-encoded channel activators and optogenetic tools are restricted by gene delivery challenges and biosafety concerns. Here a novel terahertz (THz) wave-based method to upregulate Ca_V1.2, a key subtype of Ca_V, and boost Ca_V1-mediated Ca²⁺ signaling in neurons without introducing exogenous DNA is presented. Using molecular dynamics simulations, it is shown that 42.5 THz (7.05 µm, 1418 cm⁻¹) waves enhance Ca²⁺ conductance in Ca_V1.2 by resonating with the stretching mode of the -COO⁻ group in the selectivity filter. Electrophysiological recordings and Ca²⁺ imaging confirm that these waves rapidly, reversibly, and non-thermally increase calcium influx of Ca_V1.2 in HEK293 cells and induce acute Ca²⁺ signals in neurons. Furthermore, this irradiation upregulates critical Ca_V1 signals, including CREB phosphorylation and c-Fos expression, in vitro and in vivo, without raising significant biosafety risks. This DNA-free, non-invasive approach offers a promising approach for modulating Ca_V gating and Ca²⁺ signaling and treating diseases characterized by deficits in Ca_V functions.