Chemosensation in the Ventricles of the Central Nervous System

Abstract The choroid plexus-cerebrospinal fluid system in the ventricles of the brain is a source of chemosensory cues and the composition of the cerebrospinal fluid closely reflects the physiological and pathophysiological status of the organism. Via this route, chemical information from various sources is relayed to distant brain regions and can influence a wide variety of biological processes including brain development and behavior. How are signaling molecules in the cerebrospinal fluid detected and how is information carried by these cues subsequently relayed to specific brain areas? Recent studies have provided experimental evidence that tanycytes, a population of specialized chemosensory cells located in the wall of the third ventricle, play a prominent role in these processes, in particular in the regulation of metabolism and reproduction as well as in adult neurogenesis.