The BBC highlights a recent study titled “Parental olfactory experience influences behavior and neural structure in subsequent generations” in which the researchers at Emory University in Atlanta, GA trained mice to avoid a smell, and subsequently, these mice passed this aversion on to their “grandchildren.” The results are important for phobia and anxiety research.
Both the mice’s offspring, and their offspring, were “extremely sensitive” to cherry blossom and would avoid the scent, despite never having experiencing it in their lives. Remarkably, these changes extended to changes in brain structure.
From the abstract:
Using olfactory molecular specificity, we examined the inheritance of parental traumatic exposure, a phenomenon that has been frequently observed, but not understood. We subjected F0 mice to odor fear conditioning before conception and found that subsequently conceived F1 and F2 generations had an increased behavioral sensitivity to the F0-conditioned odor, but not to other odors. When an odor (acetophenone) that activates a known odorant receptor (Olfr151) was used to condition F0 mice, the behavioral sensitivity of the F1 and F2 generations to acetophenone was complemented by an enhanced neuroanatomical representation of the Olfr151 pathway. Bisulfite sequencing of sperm DNA from conditioned F0 males and F1 naive offspring revealed CpG hypomethylation in the Olfr151 gene. In addition, in vitro fertilization, F2 inheritance and cross-fostering revealed that these transgenerational effects are inherited via parental gametes. Our findings provide a framework for addressing how environmental information may be inherited transgenerationally at behavioral, neuroanatomical and epigenetic levels.