Insulin and ghrelin: peripheral hormones modulating memory and hippocampal function.
Peptide hormones, initially identified in the periphery and best known for regulation of food intake and appetite, have increasingly been shown to regulate brain functions not only within the hypothalamus but elsewhere. The hippocampus, in particular, expresses receptors for many hormones. Both insulin and ghrelin are now known to enhance hippocampal memory processes; in addition, insulin acts to increase local hippocampal metabolism and regulate synaptic plasticity, while administration of ghrelin has been shown to promote dendritic spine synaptic formation and to increase anxiety. While insulin's effects appear to be specifically within the hippocampus, ghrelin may act at a range of sites within the limbic system.
McNay
Ewan C
EC
Yale School of Medicine, Section of Endocrinology, 1 Gilbert Street, New Haven, CT 06520, USA. ewan.mcnay@yale.edu
D000818:Animals; D003071:Cognition / Q000502:physiology; D054439:Ghrelin / Q000502:physiology*; D006624:Hippocampus / Q000502:physiology*; D006801:Humans; D007328:Insulin / Q000502:physiology*; D008568:Memory / Q000502:physiology*; D008660:Metabolism / Q000502:physiology; D009479:Neuropeptides / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology; D013569:Synapses / Q000502:physiology
D054439:Ghrelin; D007328:Insulin; D009479:Neuropeptides