Summary: Researchers report life experiences may be transgenerationally inherited through a combination of epigenetics and parental behavior.
Mice growing up in a basic cage maintain lifelong visual cortex plasticity if their parents were raised in an environment that promoted social interaction and physical and mental stimulation, according to a multigenerational study published in eNeuro.
The research suggests life experience may be transmitted from one generation to the next through a combination of changes in gene expression and parental caretaking behavior.
Blocking visual input to one eye of adult mice leads to a rewiring of the visual cortex to prioritize input from the open eye. Siegrid Löwel and colleagues first confirmed that this plasticity declines over time in mice housed in standard cages while it is preserved throughout life in mice raised in an enriched environment — in this case a large, two-story cage with separate living and eating areas connected by a ladder, regularly changed mazes, and a slide.
The researchers then bred the mice to create three experimental groups of offspring, all of which were raised in standard cages. Despite being raised in the same impoverished environment, mice whose parents — particularly mothers — were raised in the enriched environment maintained lifelong plasticity in the visual cortex. These findings emphasize the importance of documenting rearing conditions of experimental animals across generations.
Funding: German Federal Ministry of Education and Research, Deutsche Forschungsgemeinschaft funded this study.
Source: David Barnstone – SfN
Publisher: Organized by NeuroscienceNews.com.
Image Source: NeuroscienceNews.com image is credited to Kalogeraki, Yusifov, and Löwel, eNeuro (2019).
Original Research: Abstract for “Transgenerational transmission of enhanced ocular dominance plasticity from enriched mice to their non-enriched offspring” by Evgenia Kalogeraki, Rashad Yusifov and Siegrid Löwel in eNeuro. Published January 21 2019.
Transgenerational transmission of enhanced ocular dominance plasticity from enriched mice to their non-enriched offspring
In recent years, evidence has accumulated that non-Mendelian transgenerational inheritance of qualities acquired through experience is possible. In particular, it has been shown that raising rodents in a so-called enriched environment (EE) can not only modify the animals’ behaviour and increase their susceptibility to activity-dependent neuronal network changes, but also influences both behaviour and neuronal plasticity of the non-enriched offspring. Here, we tested whether such a transgenerational transmission can also be observed in the primary visual cortex (V1) using ocular dominance (OD) plasticity after monocular deprivation (MD) as a paradigm. While OD-plasticity after 7 days of MD is absent in standard-cage (SC) raised mice beyond postnatal day (P) 110, it is present lifelong in EE-raised mice. Using intrinsic signal optical imaging to visualize cortical activity, we confirm these previous observations and additionally show that OD-plasticity is not only preserved in adult EE-mice but also in their adult non-enriched offspring: mice born to enriched parents, but raised in SCs at least until P110 displayed similar OD-shifts towards the open eye after 7 days of MD as age-matched EE-raised animals. Furthermore, testing the offspring of EE-female versus EE-males with SC-mating partners revealed that only pups of EE-females, but not of EE-males, preserved OD-plasticity into adulthood, suggesting that the life experiences of the mother have a greater impact on the continued V1-plasticity of the offspring. The OD-plasticity of the non-enriched pups of EE-mothers was, however, mechanistically different from that of non-enriched pups of EE-parents or EE-mice.
Recently evidence is accumulating that life experiences and thus acquired qualities of parents can be transmitted across generations in a non-Mendelian fashion and have a significant impact on the fitness of offspring. Raising mice in a so-called enriched environment with enhanced opportunities for social interaction, voluntary physical exercise and explorative behaviour has been shown to boost cortical plasticity. Our results now show that the plasticity-promoting effect of enrichment on ocular dominance plasticity, a well-established plasticity paradigm in a primary sensory cortex, can also be transmitted from enriched parents to their non-enriched offspring. Thus cortical plasticity is not only influenced by an animal’s life experiences but can also be modified by the life experiences of its parents.