Insulin receptor β-subunit haploinsufficiency impairs hippocampal late-phase LTP and recognition memory

Neuromolecular Med. 2012 Dec;14(4):262-9. doi: 10.1007/s12017-012-8184-z. Epub 2012 Jun 3.

Abstract

The insulin receptor (IR) is a protein tyrosine kinase playing a pivotal role in the regulation of peripheral glucose metabolism and energy homoeostasis. IRs are also abundantly distributed in the cerebral cortex and hippocampus, where they regulate synaptic activity required for learning and memory. As the major anabolic hormone in mammals, insulin stimulates protein synthesis partially through the activation of the PI3K/Akt/mTOR pathway, playing fundamental roles in neuronal development, synaptic plasticity and memory. Here, by means of a multidisciplinary approach, we report that long-term synaptic plasticity and recognition memory are impaired in IR β-subunit heterozygous mice. Since IR expression is diminished in type-2 diabetes as well as in Alzheimer's disease (AD) patients, these data may provide a mechanistic link between insulin resistance, impaired synaptic transmission and cognitive decline in humans with metabolic disorders.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alzheimer Disease / metabolism
  • Alzheimer Disease / psychology
  • Animals
  • Diabetes Mellitus, Type 2 / metabolism
  • Diabetes Mellitus, Type 2 / psychology
  • Female
  • Heterozygote
  • Hippocampus / physiopathology*
  • Humans
  • Insulin Resistance
  • Learning Disabilities / genetics*
  • Learning Disabilities / physiopathology
  • Long-Term Potentiation / genetics*
  • Memory Disorders / genetics*
  • Memory Disorders / physiopathology
  • Mice
  • Nerve Tissue Proteins / deficiency*
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / physiology
  • Phosphatidylinositol 3-Kinases / physiology
  • Post-Synaptic Density / ultrastructure
  • Proto-Oncogene Proteins c-akt / physiology
  • Receptor, Insulin / deficiency*
  • Receptor, Insulin / genetics
  • Receptor, Insulin / physiology
  • Recognition, Psychology*
  • Signal Transduction / physiology
  • Synaptic Transmission / genetics
  • TOR Serine-Threonine Kinases / physiology

Substances

  • Nerve Tissue Proteins
  • mTOR protein, mouse
  • Receptor, Insulin
  • Akt1 protein, mouse
  • Proto-Oncogene Proteins c-akt
  • TOR Serine-Threonine Kinases