How Do Planarians Grow a New Brain?

April 21, 2023

Kendall Clay head shot — Kendall Clay, ComSciCon-Atlanta 2022

by Kendall Clay (ComSciCon-Atlanta 2022)

Planarians are aquatic flatworms that can regenerate, or regrow, new body parts--including a brain!

A comic strip depicting how planarians grow a new brain.

My research project started with a collaborative genetic screen. Taylor Medlock-Lanier and I joined the lab at the same time and started working through a list of 74 genes to identify those important for dopaminergic neurons in planarians. When we completed the screen, we found some surprising differences – some genes were important for dopaminergic neurons in the brain, and other genes were important for dopaminergic neurons in the periphery. We have split the project, but continue to work together, bouncing ideas off each other and collaborating to publish a paper on our findings.

Every time I explain my work, everyone is fascinated that these aquatic flatworms can grow new body parts after injury, but they don’t understand how. Through visual media, I have been able to better communicate how regeneration works in this seemingly simple organism. Drawing the process makes it easier to follow the timeline of growth, patterning, and specialization.

Not only can planarians regenerate, but they also can see! They have a complex nervous system linked to two eyespots that can detect light. These worms use motile cilia and muscular contractions to glide along the surface of their environment, picking up food through a muscular organ called the pharynx. It’s like a mobile mouth that extends from the body cavity, senses food, and uses contractions to pull food particles into the body. Waste is ejected through the same hole. Despite the simple structure, planarians are a fascinating organism with measurable behaviors linked to cell types throughout the body, These cells are specified by a vast complement of genetic factors, many of which are similar to other invertebrates and some common vertebrate homologs.

Through my research, I hope to better understand how planarians regenerate dopaminergic neurons. This research will lead the way to understanding how their complex nervous system made of many different cell types is made anew after injury. By elucidating genetic roles in cell specification, this work may be applicable to stem cell programming research for human diseases such as Parkinson’s.

----------------------------------------------

Kendall Clay is a PhD candidate at the University of Georgia. Her research focuses on characterizing genes involved in the regeneration of dopaminergic neurons in planarians. Kendall is an aspiring science communicator developing skills in writing and data visualization, and outside the lab, she enjoys painting, reading, and hiking with friends.

Twitter: @kendallbclay

TikTok: @wormsquadlab

Website: kendallclay.weebly.com