Abstract

Myogenesis, the process of muscle fiber formation, is a tightly regulated cellular event critical for development and regeneration. This study investigates the mechanism by which Gamma-Aminobutyric Acid (GABA) exerts an inhibitory effect on myotube formation in an *in vitro* cell culture model. Given that GABA is a major inhibitory neurotransmitter, its role in non-neuronal tissues, particularly muscle development, is of significant interest. Using C2C12 myoblast cell lines, we employed a combination of pharmacological manipulation, immunofluorescence microscopy to assess differentiation markers (e.g., MyoD, Myogenin), and quantitative real-time PCR to monitor gene expression profiles. Our key findings demonstrate that GABA treatment significantly reduces the fusion index and myotube diameter in a dose-dependent manner. Mechanistically, this inhibition is mediated through the activation of GABA-A receptors expressed on the myoblast membrane, leading to an influx of chloride ions and subsequent hyperpolarization. This change in membrane potential appears to interfere with the necessary signaling cascades, such as the p38 MAPK pathway, required for terminal differentiation. These results highlight a novel role for GABA as a negative regulator of myogenesis, suggesting that GABAergic signaling pathways may represent potential therapeutic targets for modulating muscle regeneration and treating muscle-wasting disorders.