Zebrafish as a Versatile Screening Model for Neurological Diseases: Insights Into Biology, Drug Delivery and Therapeutic Discovery.

Neurological diseases such as Alzheimer's disease, Parkinson's disease, anxiety, depression, and Huntington's disease pose significant challenges due to their complex pathophysiology and limited treatment options. Traditional mammalian models, although widely used, often face limitations in cost, ethical concerns, and scalability. Zebrafish have become an excellent animal model for neurological research in recent years because of their remarkable genetic similarity to humans, well-preserved neurotransmitter systems, and readiness for high-throughput behavioural and pharmacological investigations. This review provides a comprehensive overview of the role of zebrafish in modelling neurological disorders and drug discovery. It first highlights the anatomical and neurochemical features of the zebrafish nervous system, followed by various drug administration strategies, including bath immersion, microinjection, oral administration and advanced delivery systems such as nanoparticles, hydrogels, and genetic manipulation techniques. Furthermore, the review explores zebrafish models for major neurological and psychiatric disorders, emphasizing their applications in drug screening, evaluation of neuroprotective compounds and repurposing therapeutics. Additionally, the future perspectives address innovations in genetic engineering, targeted delivery systems, and the integration of omics technologies for translational neuroscience research. Despite inherent limitations and differences from mammalian systems, zebrafish offers unique advantages as an in vivo screening platform.