When mice grow up in a stimulating environment—for example, in large cages with running wheels and labyrinths and several other mice—their brain remains adaptable, or plastic, for longer. In fact, according to a study published this week in eNeuro,not only these mice but also their offspring benefit from this enrichment, even if the offspring do not themselves grow up in a stimulating environment.
In both parents and offspring, this transgenerational transmission of increased neuronal plasticity also occurs in a primary sensory area of the cerebral cortex.
To begin the study, a research team from the Department of Systems Neuroscience at the University of Göttingen raised mice in particularly large cages. The environment included running wheels, various mazes, and several other mice. In order to measure plasticity, the researchers allowed the adult animals to see through only one eye for several days and imaged the resulting activity changes in the visual cortex—a brain region that processes visual information.
“Mice that grow up in this stimulating environment display increased plasticity in their visual cortex, even into late adulthood,” says senior author Siegrid Löwel.
After the mouse parents mated, the pregnant mouse mothers were transferred to standard cages (much smaller cages without running wheels and labyrinths), and the brain plasticity of the offspring was then investigated once they were adults. The new findings show that a stimulating environment extends the period of youthful adaptability in the brain not only in mouse parents but also in their offspring, even if the offspring grew up in a less stimulating environment.
“In addition, the mouse mother seems to have a greater influence on visual cortical plasticity of the offspring,” Löwel adds.
Overall, the researchers found that cortical plasticity is not only influenced by one’s own life experiences. It can also be significantly modified by the parents’ life experiences.
Image: Evidence is accumulating that life experiences of the parent can be transmitted across generations. Imaging of neuronal activity shows that—after several days of monocular vision (black dot)—the mouse primary visual cortex (V1) is more plastic in mice whose parents experienced a stimulating environment (bottom row) compared with mice whose parents experienced a standard cage (top row). Thus, the environment experienced by parents can strongly affect brain plasticity of the offspring. Abbreviations: OD = ocular dominance. Image courtesy of Siegrid Löwel.