Many promising tools recently developed for biological research rely heavily on principles of pharmacology. This session will focus on novel tools that are being used to explore pharmacological and biological questions with unprecedented precision. Talks will focus on the development of novel optical sensors for monitoring peptide release in awake and behaving animals, Drugs Acutely Restricted by Tethering (DART) which allow for cell type-specific pharmacology in intact systems, and new tools for the control and modulation of GPCR signaling. Together, this session will demonstrate how the next generation of pharmacological tools is unlocking new frontiers for understanding biological functions.