Early weaning impairs fear extinction and decreases brain-derived neurotrophic factor expression in the prefrontal cortex of adult male C57BL/6 mice

Dev Psychobiol. 2016 Dec;58(8):1034-1042. doi: 10.1002/dev.21437. Epub 2016 Jun 13.


We examined the developmental effects of early weaning on anxiety and the extinction of fear memory in male C57BL/6 mice. Early weaning led to increased freezing behaviors after fear conditioning via the foot-shock method both during extinction training and in a test of extinction recall, but did not induce significant changes in anxiety-like behavior. In addition, we found that the levels of brain-derived neurotrophic factor (BDNF) protein and mRNA transcripts for BDNF exon III in the medial prefrontal cortex (mPFC) at the time of extinction recall were impaired in early-weaned mice compared to normally weaned mice. In light of consistent finding that early-weaned mice experience greater stress at weaning, these data suggest that early weaning of male C57BL/6 mice is valuable for studies of the pathogenesis of post-traumatic stress disorder.

Keywords: BDNF; PTSD; early weaning; fear extinction; mice.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Animals
  • Brain-Derived Neurotrophic Factor / metabolism*
  • Conditioning, Classical / physiology*
  • Extinction, Psychological / physiology*
  • Fear / physiology*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Prefrontal Cortex / metabolism*
  • Weaning*


  • Brain-Derived Neurotrophic Factor