Origin of cerebrospinal fluid melatonin and possible function in the integration of photoperiod

摘要: Melatonin, which is synthesized at night by the pineal gland, present in cerebrospinal fluid (CSF), but its entry site and role this compartment are not known. Using several approaches, we tested hypothesis that melatonin enters CSF through recess, an evagination of third ventricle. concentrations higher near gland than anterior part ventricle, decrease markedly (80%) after sealing off recess. Moreover, ultrastructure permeability analyses pineal-CSF interface showed could reach either via delivery situ protruding pinealocytes make direct contact with or extracellular secretion interstitial draining into ventricular lumen. These data indicate probably originates from a few basal neighbouring Melatonin carried to brain blood appears be able mediate effects photoperiod on reproduction, it unclear whether may fine-tune response both terms timing amplitude. It critical determine pathway, CSF, allows central targets more efficiently.