fukkk me too :/

The effects seen by heterochronic parabiosis, the surgical joining of two animals of different ages, include rejuvenation of multiple tissues in the old partner, and are often simplistically assumed to be caused by the exchange of macromolecules found in plasma, however, parabiosis is far more complex. For example, old animals with young partners have, through the shared circulation, continuous access to the young organs, which regulate metabolic homeostasis, wound clearance and inflammation, and provide blood oxygenation to the animals3,5. Old mice attached to young animals also benefit from environmental enrichment and youthful pheromones, which may play a role in neuronal plasticity and neurogenesis9,10. The young parabiont partially maintains an additional aged body with deteriorating organs, chronic inflammation and skewed immune responses. Additionally, young and old organ systems have an opportunity to ‘adapt’ to prolonged sharing of circulatory milieus and thus change their local influences on resident stem cells. All of the above could contribute to the observed differences in regenerative responses.

[link to www.nature.com (secure)]