Neural Plasticity 
Volume 2007 (2007), Article ID 90163, 11 pages
doi:10.1155/2007/90163
Research Article

Differential MR/GR Activation in Mice Results in Emotional States Beneficial or Impairing for Cognition

Vera Brinks, Maaike H. van der Mark, E. Ron de Kloet, and Melly S. Oitzl

 Gorlaeus Lab, Division of Medical Pharmacology, LACDR/LUMC, Leiden University, Einsteinweg 55, Leiden 2300, The Netherlands
Received 24 November 2006; Revised 1 February 2007; Accepted 5 February 2007

Recommended by Patrice Venault

Abstract

Corticosteroids regulate stress response and influence emotion, learning, and memory via two receptors in the brain, the high‐affinity mineralocorticoid (MR) and low‐affinity glucocorticoid receptor (GR). We test the hypothesis that MR- and GR-mediated effects interact in emotion and cognition when a novel situation is encountered that is relevant for a learning process. By adrenalectomy and additional constant corticosterone supplement we obtained four groups of male C57BL/6J mice with differential chronic MR and GR activations. Using a hole board task, we found that mice with continuous predominant MR and moderate GR activations were fast learners that displayed low anxiety and arousal together with high directed explorative behavior. Progressive corticosterone concentrations with predominant action via GR induced strong emotional arousal at the expense of cognitive performance. These findings underline the importance of a balanced MR/GR system for emotional and cognitive functioning that is critical for mental health.