Enhancement of memories by systemic administration of insulin-like growth factor II

Neuropsychopharmacology. 2014 Aug;39(9):2179-90. doi: 10.1038/npp.2014.69. Epub 2014 Mar 19.


To treat cognitive disorders in humans, new effective therapies that can be easily delivered systemically are needed. Previous studies showed that a bilateral injection of insulin-like growth factor II (IGF-II) into the dorsal hippocampus of rats or mice enhances fear memories and facilitates fear extinction. Here, we report that, in mice, systemic treatments with IGF-II given before training significantly enhance the retention and persistence of several types of working, short-term and long-term memories, including fear conditioning, object recognition, object placement, social recognition, and spatial reference memory. IGF-II-mediated memory enhancement does not alter memory flexibility or the ability for new learning and also occurs when IGF-II treatment is given in concert with memory retrieval. Thus IGF-II may represent a potentially important and effective treatment for enhancing human cognitive and executive functions.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Brain / drug effects
  • Brain / physiology
  • Conditioning, Psychological / drug effects
  • Conditioning, Psychological / physiology
  • Fear / drug effects
  • Fear / physiology
  • Genes, Immediate-Early / drug effects
  • Genes, Immediate-Early / physiology
  • Insulin-Like Growth Factor II / adverse effects
  • Insulin-Like Growth Factor II / pharmacology*
  • Learning / drug effects
  • Learning / physiology
  • Male
  • Memory, Long-Term / drug effects*
  • Memory, Long-Term / physiology
  • Memory, Short-Term / drug effects*
  • Memory, Short-Term / physiology
  • Mice, Inbred C57BL
  • Nootropic Agents / adverse effects
  • Nootropic Agents / pharmacology*
  • Receptor, IGF Type 2 / metabolism
  • Recognition, Psychology / drug effects
  • Recognition, Psychology / physiology
  • Recombinant Proteins / adverse effects
  • Recombinant Proteins / pharmacology
  • Social Perception
  • Spatial Memory / drug effects
  • Spatial Memory / physiology


  • Nootropic Agents
  • Receptor, IGF Type 2
  • Recombinant Proteins
  • Insulin-Like Growth Factor II