Cocaine-induced chromatin remodeling increases brain-derived neurotrophic factor transcription in the rat medial prefrontal cortex, which alters the reinforcing efficacy of cocaine

J Neurosci. 2010 Sep 1;30(35):11735-44. doi: 10.1523/JNEUROSCI.2328-10.2010.

Abstract

Cocaine self-administration alters patterns of gene expression in the brain that may underlie cocaine-induced neuronal plasticity. In the present study, male Sprague Dawley rats were allowed to self-administer cocaine (0.25 mg/infusion) 2 h/d for 14 d, followed by 7 d of forced abstinence. Compared with yoked saline control rats, cocaine self-administration resulted in increased brain-derived neurotrophic factor (BDNF) protein levels in the rat medial prefrontal cortex (mPFC). To examine the functional relevance of this finding, cocaine self-administration maintained under a progressive ratio schedule of reinforcement was assessed after short hairpin RNA-induced suppression of BDNF expression in the mPFC. Decreased BDNF expression in the mPFC increased the cocaine self-administration breakpoint. Next, the effect of cocaine self-administration on specific BDNF exons was assessed; results revealed selectively increased BDNF exon IV-containing transcripts in the mPFC. Moreover, there were significant cocaine-induced increases in acetylated histone H3 (AcH3) and phospho-cAMP response element binding protein (pCREB) association with BDNF promoter IV. In contrast, there was decreased methyl-CpG-binding protein 2 (MeCP2) association with BDNF promoter IV in the mPFC of rats that previously self-administered cocaine. Together, these results indicate that cocaine-induced increases in BDNF promoter IV transcript in the mPFC are driven by increased binding of AcH3 and pCREB as well as decreased MeCP2 binding at this BDNF promoter. Collectively, these results indicate that cocaine self-administration remodels chromatin in the mPFC, resulting in increased expression of BDNF, which appears to represent a compensatory neuroadaptation that reduces the reinforcing efficacy of cocaine.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Behavior, Addictive / metabolism
  • Behavior, Addictive / psychology
  • Brain-Derived Neurotrophic Factor / biosynthesis*
  • Brain-Derived Neurotrophic Factor / genetics*
  • Chromatin Assembly and Disassembly / drug effects*
  • Chromatin Assembly and Disassembly / physiology*
  • Cocaine / administration & dosage*
  • Cocaine / pharmacology
  • Cocaine-Related Disorders / metabolism
  • Cocaine-Related Disorders / psychology
  • Male
  • Prefrontal Cortex / drug effects*
  • Prefrontal Cortex / metabolism*
  • Rats
  • Rats, Sprague-Dawley
  • Reinforcement, Psychology*
  • Self Administration
  • Transcription, Genetic / drug effects
  • Transcription, Genetic / physiology
  • Up-Regulation / drug effects
  • Up-Regulation / physiology

Substances

  • Brain-Derived Neurotrophic Factor
  • Cocaine