Reversible Antagonism of Dopamine D1 Receptor Using a Photoswitchable Remotely Tethered Ligand

Dopamine D1 receptor (D1R) plays key roles in health and disease. D1R is broadly expressed throughout the brain and body and is dynamically activated in response to endogenous dopamine, making it difficult to target this receptor with sufficient precision. We previously developed a robust light-activatable, tetherable agonist for D1R, wherein a temporally precise photoswitch (the P compound) binds to a genetically encoded membrane anchoring protein (the M protein) in specific brain locations and cell types. Here we extended our approach by developing a complementary antagonist P compound that could be used to block specific populations of D1R in the brain with precise timing. Together, we have generated a robust toolkit for interrogating D1R function in the brain with unprecedented precision.