Central nervous system (CNS) structures involved in the regulation of energy balance gather information from the variety of different peripherally derived signaling molecules that we now believe provide an integrated perspective of energy status of the organism. However, the existence of the blood brain barrier means that the CNS is theoretically unable to directly monitor many of these circulating signals such as adiponectin, amylin, cholecystokinin (CCK), glucose, ghrelin, leptin, and peptide YY (PYY) which do not freely diffuse across this barrier. A number of mechanisms have been suggested to play important roles in facilitating the ability of the CNS to monitor this essential sensory information. My presentation will describe briefly potential roles of vagal afferent signaling and peptide transporters in providing access routes for such information transfer, but will focus primarily on the potential roles of specialised CNS structures which lack the blood brain barrier known as the sensory circumventricular organs (CVOs). In particular I will highlight the complex sensory abilities of single CVO neurons in sensing multiple satiety signals and also describe the efferent projections of these neurons to essential autonomic control centres behind the blood brain barrier.