Figure 6.Central and efferent pathways regulating energy expenditure. Diet and cold is sensed by the brain. In the case of diet-induced thermogenesis, a strong case can be made for the role of aMSH neurons in the arcuate nucleus of the hypothalamus which project to neurons in the paraventricular nucleus of the hypothalamus controlling sympathetic outflow, as well as to sympathetic preganglionic neurons located in the intermedial lateral column of the spinal cord. As discussed in the text, MC4Rs are likely to play an important role. These pathways lead to increased activity of sympathetic nerves which release norepinephrine, activating bARs. This has acute and chronic effects on brown adipocytes which promote increased thermogenesis. This figure was adapted from reference (29).