A neuroanatomical model of GLP-1’s actions in the rat brain. Circulating GLP-1 engages GLP-1Rs on the hypothalamic neurons in the PVH, Arc, and LHA, and medullary catecholamine neurons in the A5, RVLM, and CVLM, probably through the AP and NTS where GLP-1 neurons are located. These GLP-1–activated neurons in the hypothalamus and brainstem have monosynaptic descending projections to the sympathetic preganglionic neurons in the IML, which innervate the adrenal medulla and heart to increase BP and HR (autonomic responses). This model predicts that some of the medullary catecholamine neurons project to the hypothalamic neurons. GLP-1–activated neurons in the PVH also act on the pituitary to engage neuroendocrine responses.