Fruit flies are first known animals that can taste alkaline foods

Fruit flies (Drosophila melanogaster) have surprised researchers with an entirely new taste receptor that allows them to detect alkaline — or basic — substances and avoid toxic meals and surfaces. The flies have an unusual mechanism: a receptor protein that, in the presence of a base, opens a cell-membrane channel through which negatively charged chloride ions escape the neuron. Most sensory receptors involve channels that let positively charged ions flow into the cell. Some studies in people and cats suggest that they, too, experience alkaline as a type of taste.