Diabetes is a lifelong, chronic health condition caused by abnormalities in the body’s production and use of the hormone insulin. Research has shown that the feel-good hormone, dopamine (DA), plays a key role in how the body regulates the production of insulin. Typically, insulin is secreted by cells in the pancreas called “beta-cells,” in response to glucose—a process that is aptly called “glucose-stimulated insulin secretion (GSIS).” DA negatively regulates GSIS, leading to transient changes in the body’s levels of insulins. But the mechanism behind this regulation was unknown, until now. Recently, a team led by researchers from Tokyo Institute of Technology (Tokyo Tech) uncovered the precise mechanism through which DA regulates insulin secretions. Using a technique called “total internal reflection fluorescence microscopy,” the scientists were able to reveal that DA “receptors”—proteins on cells that DA can bind to—called D1 and D2, act in concert to achieve the transient regulation of insulin.