Ghrelin is a stomach hormone, secreted into the bloodstream, that initiates food intake by
activating NPY/AgRP neurons in the hypothalamic acruate nucleus. This review focuses on
recent evidence that details the mechanisms through which ghrelin activate receptors on
NPY neurons and downstream signaling within NPY neurons. The downstream signaling
involves a novel CaMKK-AMPK-CPT1-UCP2 pathway that enhances mitochondrial
efficiency and buffers reactive oxygen species in order to maintain an appropriate firing …