RS-25560-198 HCl is a chemical compound primarily utilized in research settings, particularly in pharmacology and neuroscience. It acts as a selective antagonist for serotonin receptors (5-HT receptors), which play a crucial role in the central nervous system. This compound is commonly used to test the activity and specificity against various serotonin receptor subtypes, aiding in the development of new drugs for psychiatric conditions such as depression, anxiety disorders, and other neurological abnormalities. Additionally, it is employed in research to understand the functioning of the serotonin system in the body and its impacts on behavior and emotions in humans and animal models.