Involvement of Epigenetic Modifications of GABAergic Interneurons in Basolateral Amygdala in Anxiety-like Phenotype of Prenatally Stressed Mice

Int J Neuropsychopharmacol. 2018 Jun 1;21(6):570-581. doi: 10.1093/ijnp/pyy006.

Abstract

Background: Prenatal stress is considered a risk factor for anxiety disorder. Downregulation in the expression of GABAergic gene, that is, glutamic acid decarboxylase 67, associated with DNA methyltransferase overexpression in GABAergic neurons has been regarded as a characteristic component of anxiety disorder. Prenatal stress has an adverse effect on the development of the basolateral amygdala, which is a key region in anxiety regulation. The aim of this study is to analyze the possibility of epigenetic alterations of GABAergic neurons in the basolateral amygdala participating in prenatal stress-induced anxiety.

Methods: Behavioral tests were used to explore the prenatal stress-induced anxiety behaviors of female adult mice. Real-time RT-PCR, western blot, chromatin immunoprecipitation, and electrophysiological analysis were employed to detect epigenetic changes of GABAergic system in the basolateral amygdala.

Results: Prenatal stress mice developed an anxiety-like phenotype accompanied by a significant increase of DNA methyltransferase 1 and a reduced expression of glutamic acid decarboxylase 67 in the basolateral amygdala. Prenatal stress mice also showed the increased binding of DNA methyltransferase 1 and methyl CpG binding protein 2 to glutamic acid decarboxylase 67 promoter region. The decrease of glutamic acid decarboxylase 67 transcript was paralleled by an enrichment of 5-methylcytosine in glutamic acid decarboxylase 67 promoter regions. Electrophysiological study revealed the increase of postsynaptic neuronal excitability in the cortical-basolateral amygdala synaptic transmission of prenatal stress mice. 5-Aza-deoxycytidine treatment restored the increased synaptic transmission and anxiety-like behaviors in prenatal stress mice via improving GABAergic system.

Conclusion: The above results suggest that DNA epigenetic modifications of GABAergic interneurons in the basolateral amygdala participate in the etiology of anxiety-like phenotype in prenatal stress mice.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anxiety / genetics
  • Anxiety / metabolism
  • Anxiety Disorders / genetics
  • Anxiety Disorders / metabolism*
  • Basolateral Nuclear Complex / metabolism*
  • DNA (Cytosine-5-)-Methyltransferase 1 / metabolism
  • DNA Methylation
  • Disease Models, Animal
  • Female
  • GABAergic Neurons / metabolism*
  • Glutamate Decarboxylase / genetics
  • Glutamate Decarboxylase / metabolism
  • Interneurons / metabolism*
  • Mice, Inbred C57BL
  • Phenotype
  • Pregnancy
  • Prenatal Exposure Delayed Effects / genetics
  • Prenatal Exposure Delayed Effects / metabolism
  • Promoter Regions, Genetic
  • Stress, Psychological / genetics
  • Stress, Psychological / metabolism
  • Tissue Culture Techniques

Substances

  • DNA (Cytosine-5-)-Methyltransferase 1
  • Dnmt1 protein, mouse
  • Glutamate Decarboxylase
  • glutamate decarboxylase 1