Mouse α1B‐adrenergic receptor is expressed in neurons and NG2 oligodendrocytes

Adrenergic receptors (ARs) are well-known mediators of the sympathetic nervous system, are highly abundant in the brain, but are the least understood in the central nervous system. The particular cell types in the brain that contain these receptors or their functions are not known because of the lack of high avidity antibodies and selective ligands. We developed transgenic mice that endogenously overexpress the 1B-AR subtype fused with the enhanced green fluorescent protein (EGFP). Endogenous expression was obtained by using a 3.4 kb fragment of the mouse 1B-AR promoter. Using this model, we determined cellular localization of the 1B-AR throughout the brain. The 1B-AR-EGFP fusion protein is expressed in neurons throughout the brain and in the Purkinje cells of the cerebellum. The 1B-AR is also expressed in NG2 oligodendrocyte precursor cells in both neonatal cell cultures and in the adult cerebral cortex, but is weakly expressed in mature oligodendrocytes. The 1B-AR was not observed in astrocytes or in cerebral vascular smooth muscle, cell types previously suggested to contain 1-ARs. We conclude that the 1B-AR is highly abundant throughout the brain, predominately in neurons, and may be involved in the development of the oligodendrocyte. In adult NG2 cells, implicated in stem cell-like functions, the 1B-AR may also play a role. This is the first report of a transgenic tagged-GPCR