Figure 3.

Overview of the involvement of orexin in a neural network regulating nonexercise activity thermogenesis (NEAT), indicating a sample of the brain areas, neuropeptides, and transmitters involved. Colors correspond to specific neuropeptide/hormone as follows: Black circles/projections: orexin; green, dopamine; orange, serotonin; pink, histamine; blue, norepinephrine; brown, neuropeptide Y/agouti-related protein (NPY/AgRP) and proopiomelanocortin/cocaine and amphetamine-related transcript (POMC/CART). Signals from all of these areas have the potential to influence cortical premotor neurons (indicated by arrows), and feedback from premotor neurons and orexinergic projections may interact to drive SPA. See the text for details. CCK, cholecystokinin; DR, dorsal raphe; LC, locus coeruleus; LH, lateral hypothalamus; NAccSH, shell of nucleus accumbens; NMU, neuromedin U; PVN, hypothalamic paraventricular nucleus; VTA, ventral tegmental area; rLH, rostral LH; SN, substantia nigra; TMN, tuberomammillary nucleus. Brain areas are not all to scale, and connections and neuropeptides/transmitters indicated are not all inclusive. Not all connections shown are discussed in this review. Figure modified from work by Kotz et al.⁹²