Researchers who injected the chemical called Cart - cocaine and amphetamine regulated transcript - into rats found the amount they ate was cut by almost a third. When they injected antibodies to block the effect of the Cart they ate more.
They believe that Cart may be partly responsible for producing a feeling of fullness after eating. The discovery of a neurotransmitter responsible for controlling appetite would mark a leap forward in the search for treatments for obesity, because neurotransmitters are by definition related to the control of normal physiological processes and should be easy to modify with drugs.
However, the researchers warn there are many chemicals regulating appetite and eating and if one is knocked out the brain will eventually learn to compensate.