ML133 hydrochloride is primarily used in neuroscience research as a selective inhibitor of the Kv1.3 potassium channel. This compound helps in studying the role of Kv1.3 channels in neuronal excitability and immune cell function. Due to its ability to cross the blood-brain barrier, it is valuable in investigating neuroinflammatory conditions and neurodegenerative diseases such as Alzheimer's and multiple sclerosis. It has also been explored for its potential immunomodulatory effects, particularly in T-cell mediated responses, making it a tool compound in autoimmune disease research. Its selectivity allows for precise manipulation of ion channel activity in cellular and animal models, supporting drug development and mechanistic studies.