SB-399885 hydrochloride is primarily utilized in neuroscience research as a selective antagonist for the 5-HT6 receptor. This compound is instrumental in studying the role of serotonin receptors in the central nervous system, particularly in relation to cognitive functions, memory, and learning processes. Researchers employ it to investigate potential therapeutic applications for neurological disorders such as Alzheimer's disease, schizophrenia, and depression. By blocking the 5-HT6 receptor, it helps elucidate the receptor's involvement in modulating neurotransmitter release and its impact on behavior and cognition. Additionally, it serves as a valuable tool in preclinical studies to evaluate the efficacy of new drugs targeting serotonin pathways.