Cognitive impairment and gene expression alterations in a rodent model of binge eating disorder

Physiol Behav. 2017 Oct 15:180:78-90. doi: 10.1016/j.physbeh.2017.08.004. Epub 2017 Aug 15.

Abstract

Binge eating disorder (BED) is defined as recurrent, distressing over-consumption of palatable food (PF) in a short time period. Clinical studies suggest that individuals with BED may have impairments in cognitive processes, executive functioning, impulse control, and decision-making, which may play a role in sustaining binge eating behavior. These clinical reports, however, are limited and often conflicting. In this study, we used a limited access rat model of binge-like behavior in order to further explore the effects of binge eating on cognition. In binge eating prone (BEP) rats, we found novel object recognition (NOR) as well as Barnes maze reversal learning (BM-RL) deficits. Aberrant gene expression of brain derived neurotrophic factor (Bdnf) and tropomyosin receptor kinase B (TrkB) in the hippocampus (HPC)-prefrontal cortex (PFC) network was observed in BEP rats. Additionally, the NOR deficits were correlated with reductions in the expression of TrkB and insulin receptor (Ir) in the CA3 region of the hippocampus. Furthermore, up-regulation of serotonin-2C (5-HT2C) receptors in the orbitoprefrontal cortex (OFC) was associated with BM-RL deficit. Finally, in the nucleus accumbens (NAc), we found decreased dopamine receptor 2 (Drd2) expression among BEP rats. Taken together, these data suggest that binge eating vegetable shortening may induce contextual and reversal learning deficits which may be mediated, at least in part, by the altered expression of genes in the CA3-OFC-NAc neural network.

Keywords: Bdnf; Binge eating; Cognition; High fat; Serotonin receptor; TrkB.

MeSH terms

  • Analysis of Variance
  • Animals
  • Binge-Eating Disorder / complications*
  • Binge-Eating Disorder / physiopathology*
  • Body Weight
  • Brain / metabolism*
  • Brain-Derived Neurotrophic Factor / genetics
  • Brain-Derived Neurotrophic Factor / metabolism
  • Cognition Disorders / etiology*
  • Disease Models, Animal
  • Eating / physiology
  • Exploratory Behavior / physiology
  • Fats / metabolism
  • Gene Expression Regulation / physiology*
  • Male
  • Maze Learning / physiology
  • Rats
  • Rats, Sprague-Dawley
  • Receptor, Insulin / genetics
  • Receptor, Insulin / metabolism
  • Receptor, Serotonin, 5-HT2C / genetics
  • Receptor, Serotonin, 5-HT2C / metabolism
  • Receptor, trkB / genetics
  • Receptor, trkB / metabolism
  • Receptors, Dopamine D2 / genetics
  • Receptors, Dopamine D2 / metabolism
  • Recognition, Psychology / physiology

Substances

  • Brain-Derived Neurotrophic Factor
  • DRD2 protein, rat
  • Fats
  • Receptor, Serotonin, 5-HT2C
  • Receptors, Dopamine D2
  • Ntrk2 protein, rat
  • Receptor, Insulin
  • Receptor, trkB