GABBR1 encodes the gamma-aminobutyric acid type B receptor subunit 1, which forms obligatory heterodimers with GABBR2 to mediate prolonged neuronal inhibition in the central nervous system 1. The receptor functions through G protein-coupled signaling pathways, inhibiting adenylyl cyclase and modulating neurotransmitter release 2. GABBR1 plays critical roles beyond traditional neurotransmission, including regulation of hematopoietic stem and progenitor cell proliferation and function, with Gabbr1-knockout mice showing reduced HSPC numbers and diminished reconstitution capacity 3. The receptor also mediates neuro-immune interactions, as enteric GABAergic neuron-derived GABA inhibits IL-17A production in intestinal ILC3 cells through GABBR1/GABBR2-dependent pathways 4. Additionally, GABBR1 regulates specific neuronal subtypes controlling locomotion, with Gabbr1 knockdown in nigrostriatal dopaminergic neurons affecting movement termination 5. Clinically, de novo GABBR1 variants cause neurodevelopmental disorders with motor/language delays and epilepsy, with functional studies showing reduced GABA efficacy at variant receptors 1. Genetic variants in GABBR1 are also associated with methamphetamine dependence and nicotine dependence susceptibility 62.