Anandamide plays a role in the regulation of feeding behavior, and the neural generation of motivation and pleasure. Anandamide injected directly into the forebrain reward-related brain structure nucleus accumbens enhances the pleasurable responses of rats to a rewarding sucrose taste, and enhances food intake as well. Moreover, the acute beneficial effects of exercise (termed as "runner's high") seem to be mediated by anandamide in mice. Anandamide is the precursor of a class of physiologically active substances, the prostamides. Anandamide inhibits human breast cancer cell proliferation.