Figure 1.

The hypothalamic neuropeptide Y (NPY) system. Names of the areas involved in the system are indicated in italics: ARC, arcuate nucleus; PVN, paraventricular nucleus; LH, lateral hypothalamus; VMN, ventromedial nucleus; DMN, dorsomedial nucleus. The location of specific receptors is shown. The different receptors are identified once in an area by a sign and the receptor name tied to this sign (e.g. black triangle for MC4-R, black explosion for insulin, diamond for glucocorticoids, etc.). In the other nuclei, their presence is indicated by signs only. Ob-Rb, long form of the leptin receptor; MC4-R, type 4 melanocortin receptor; GHS-R, growth hormone secretagogue (ghrelin) receptor; INS-R, insulin receptor; GC-R, glucocorticoid receptor. The names of the neuronal populations connected to NPY neurons in the ARC are given in small capitals: POMC, proopiomelanocortin; CART, cocaine and amphetamine-related peptide; DYN, dynorphin; GAL, galanin; CRH, corticotropin-releasing hormone; MCH, melanin concentrating hormone; OX, orexins; TRH, thyrotropin-releasing hormone. Agouti-related peptide (AgRP) is co-localized with NPY (for more details, see Beck 2005).