Researchers have long sought to understand the mechanism by which planaria, small flatworms found in freshwater and saltwater, are able to regenerate their body parts—even their brains—after injury.

Even more impressively, they have the ability to detect when their body has been sufficiently repaired and respond by ceasing the regeneration process. Their regenerative ability is widely believed to be a potential model for tissue regeneration in humans. The ability to regenerate tissue in vivo would enable more effective treatment of heart disease, various neurodegenerative disorders, and cancer, among other conditions. Furthermore, understanding tissue regeneration would transform the field of artificial organ engineering. However, while significant progress has been made in the past decade, the mechanisms by which planaria heal injured body parts are far from being fully understood. Specifically, the global decision-making that allows planaria to restore the proper size, scale and orientation of their bodies remains largely unknown. This experiment aims to shed light on these decision-making mechanisms at the cellular level by investigating the effects of serotonergic agonist 8-OH-DPAT on two generations of planarian regeneration.