Transcriptional effects of glucocorticoid receptors in the dentate gyrus increase anxiety-related behaviors

PLoS One. 2009 Nov 2;4(11):e7704. doi: 10.1371/journal.pone.0007704.

Abstract

The Glucocorticoid Receptor (GR) is a transcription factor ubiquitously expressed in the brain. Activation of brain GRs by high levels of glucocorticoid (GC) hormones modifies a large variety of physiological and pathological-related behaviors. Unfortunately the specific cellular targets of GR-mediated behavioral effects of GC are still largely unknown. To address this issue, we generated a mutated form of the GR called DeltaGR. DeltaGR is a constitutively transcriptionally active form of the GR that is localized in the nuclei and activates transcription without binding to glucocorticoids. Using the tetracycline-regulated system (Tet-OFF), we developed an inducible transgenic approach that allows the expression of the DeltaGR in specific brain areas. We focused our study on a mouse line that expressed DeltaGR almost selectively in the glutamatergic neurons of the dentate gyrus (DG) of the hippocampus. This restricted expression of the DeltaGR increased anxiety-related behaviors without affecting other behaviors that could indirectly influence performance in anxiety-related tests. This behavioral phenotype was also associated with an up-regulation of the MAPK signaling pathway and Egr-1 protein in the DG. These findings identify glutamatergic neurons in the DG as one of the cellular substrate of stress-related pathologies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anxiety / metabolism*
  • Brain / metabolism
  • Dentate Gyrus / metabolism*
  • Early Growth Response Protein 1 / biosynthesis
  • Gene Expression Regulation*
  • Hippocampus / metabolism
  • MAP Kinase Signaling System
  • Mice
  • Mice, Inbred C57BL
  • Mutation
  • Neurons / metabolism
  • Phenotype
  • Receptors, Glucocorticoid / metabolism*
  • Transcription, Genetic*

Substances

  • Early Growth Response Protein 1
  • Egr1 protein, mouse
  • Receptors, Glucocorticoid