Epigenetic transmission of the impact of early stress across generations.
Level 5 - mechanism / opinion, no new human data
Preclinical animal study
PubMed 20673872 · doi:10.1016/j.biopsych.2010.05.036
What was done
Mice were exposed to chronic and unpredictable maternal separation from postnatal day 1 to 14. Researchers evaluated depressive-like behaviors and behavioral responses to aversive environments in the exposed mice upon reaching adulthood. These exposed males were bred to test whether behavioral alterations were transmitted to their normally reared offspring. In addition, DNA methylation profiles were analyzed in candidate gene promoters in the germline of exposed males and in the brains of their offspring, along with brain gene expression.
What was found
The abstract reports no numerical values, effect sizes, or p-values. Qualitatively, maternal separation induced depressive-like behaviors and altered behavioral responses to aversive environments in adult animals. Most behavioral alterations were transmitted to the offspring of exposed males. Early stress altered promoter DNA methylation of candidate genes in the male germline, and comparable alterations in DNA methylation alongside altered gene expression were observed in the brains of the offspring.
Why it matters
This study provides experimental evidence in a mammalian model that paternal early-life trauma can transmit behavioral and molecular alterations to subsequent generations via epigenetic changes in the germline.
Limits
The study was conducted entirely in mice, limiting direct translation to humans. The abstract omits sample sizes, specific candidate genes tested, and all quantitative measurements and statistical effect sizes.
Cited by
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