VIP-containing cells in the neocortex are intrinsic neurons of the bipolar type, which release VIP through mechanisms that involve Ca2+ and lipoxygenase metabolites. VIP receptors are coupled to cAMP-generating systems that are amplified by various neurotransmitters such as noradrenaline, histamine and GABA. Pierre Magistretti reviews the evidence that VIP neurons play an important role in the local regulation of metabolism in the cerebral cortex by stimulating glycogenolysis and altering cortical blood flow.