Fig. 1.

Dopaminergic control of food intake by reward circuit pathways. Schematic illustration of dopaminergic reward circuit pathways: the mesolimbic and mesocortical pathways, including projections from the ventral tegmental area (VTA) to the nucleus accumbens (NAc) and the prefrontal cortex (PFC). Dopamine reward systems mediate the motivational and emotional drive for food, which involves learning, associated with the hedonic properties of food and the context of food intake. It has been suggested that leptin and insulin inhibit VTA dopamine neurons, while ghrelin activates them, thereby modulating the dopamine VTA-NAc reward circuits to control feeding behavior. Possible indirect effects of these hormones from the lateral hypothalamus, or from the effector-responsive neurons to the VTA, are not depicted here and remain to be elucidated. The nigrostriatal pathway constituting the projection of neurons in the substantia nigra pars compacta (SNc) to the dorsal striatum (DS), is also depicted. The role of DS in the control of feeding behavior is discussed in the main text.