Neuronal Cilia: Another Player in the Melanocortin System

Melanocortin receptors play crucial roles in multiple physiological processes. Melanocortin receptor 4 (MC4R) is expressed in key brain regions, and MC4R gene mutations can cause severe obesity. However, the cellular biology of MC4R is less well understood owing to the lack of reliable methods to visualize its location. Recently, Siljee and colleagues localized MC4R to the cilia of the neurons within the hypothalamus and showed that cilial expression of MC4R is crucial for the control of metabolic phenotype.