Trio gene is required for mouse learning ability

Brain Res. 2015 May 22;1608:82-90. doi: 10.1016/j.brainres.2015.02.040. Epub 2015 Feb 26.

Abstract

Trio is a guanine nucleotide exchange factor with multiple guanine nucleotide exchange factor domains. Trio regulates cytoskeleton dynamics and actin remodeling and is involved in cell migration and axonal guidance in neuronal development. The null allele of the Trio gene led to embryonic lethality, and Trio null embryos displayed aberrant organization in several regions of the brain at E18.5, including hippocampus. Nestin-Trio-/- mice, in which the Trio gene was deleted specifically in the neuronal system by the Nestin-Cre system, displayed severe phenotypes, including low survival rate, ataxia and multiple developmental defects of the cerebellum. All Nestin-Trio-/- mice died before reaching adulthood, which hinders research on Trio gene function in adult mice. Thus, we generated EMX1-Trio-/- mice by crossing Trio-floxed mice with EMX1-Cre mice in which Cre is expressed in the brain cortex and hippocampus. EMX1-Trio-/- mice can survive to adulthood. Trio gene deletion results in smaller brains, an abnormal hippocampus and disordered granule cells in the dentate gyrus (DG) and cornu ammonis (CA). Behavior tests showed that Trio deletion interfered with the hippocampal-dependent spatial learning in the mice, suggesting that Trio plays critical roles in the learning ability of adult mice. We conclude that the Trio gene regulates the neuronal development of the hippocampus and that it affects the intelligence of adult mice.

Keywords: Hippocampus; Learning; Mouse; Trio.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Avoidance Learning / physiology
  • Conditioning, Psychological / physiology
  • Disease Models, Animal
  • Fear / psychology
  • Guanine Nucleotide Exchange Factors / genetics*
  • Guanine Nucleotide Exchange Factors / metabolism
  • Hippocampus / abnormalities*
  • Hippocampus / metabolism
  • Hippocampus / pathology
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism
  • Learning Disabilities / genetics*
  • Learning Disabilities / pathology*
  • Maze Learning / physiology
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Phosphoproteins / genetics*
  • Phosphoproteins / metabolism
  • Protein Serine-Threonine Kinases / genetics*
  • Protein Serine-Threonine Kinases / metabolism
  • Reaction Time / genetics
  • Statistics, Nonparametric
  • Transcription Factors / genetics
  • Transcription Factors / metabolism

Substances

  • Guanine Nucleotide Exchange Factors
  • Homeodomain Proteins
  • Phosphoproteins
  • Transcription Factors
  • Trio protein, mouse
  • empty spiracles homeobox proteins
  • Protein Serine-Threonine Kinases