A brain protein already known to play a central role in the “feast or fast” signaling that controls the urge to eat has now been found to influence appetite in a second way. The discovery identifies a potential new target for drugs against obesity.Earlier research has shown that this protein, called MC4R, is a receptor on neurons in the hypothalamus region of the brain and receives signals through at least two pathways about the status of the body’s fat reserves. If fat stores are increasing, theses signals stimulate MC4R, triggering physiological responses that decrease appetite. If fat reserves are decreasing, these signals turn off, deactivating MC4R and increasing appetite.
