MOUSE 5HT1B SEROTONIN RECEPTOR - CLONING, FUNCTIONAL EXPRESSION, AND LOCALIZATION IN MOTOR CONTROL CENTERS

Serotonin is a neuromodulator that mediates a wide range of effects by interacting with multiple receptors. Using a strategy based on nucleo tide sequence homology between genes encoding receptors that interact with guanine nucleotide-binding proteins, we have isolated a mouse gen e encoding an additional serotonin receptor. When expressed in culture d cells, it displayed the pharmacological profile and coupling with ad enylate cyclase characteristic of the 5HT1B receptor subtype. In NIH 3 T3 cells expressing this receptor, serotonin induced a decrease in for skolin-stimulated cAMP levels. This effect was blocked by pertussis to xin, indicating that the 5HT1B receptor interacts with a pertussis tox in-sensitive guanine nucleotide-binding protein. To obtain clues as to the possible function of the 5HT1B receptor, we have analyzed its pat tern of expression in the adult mouse brain by in situ hybridization. Our results, together with previous autoradiographic studies, suggest that the 5HT1B receptors are localized presynaptically on the terminal s of striatal neurons and Purkinje cells and that they might modulate the release of neurotransmitters such as gamma-aminobutyric acid. The predominant expression of the 5HT1B receptor in the striatum and cereb ellum points to an involvement of this receptor in motor control.