Pain Mechanisms of Toxins: Sam Robinson Deconstructs Stings, Poisons, and Venoms

What's a stinging tree? Hikers in Australia are familiar with this needle-covered plant that can cause hours of pain. Researcher Sam Robinson has been studying how this tree's sting causes pain, and found a connection to chemotherapy-associated pain that may help researchers find a solution. His work includes the study of numerous toxic plants and animals and the chemistry behind our painful biological reaction. He discusses

• Some fascinating examples of organisms and their toxins,
• The two main categories of toxins and how they work on a broad scale, and
• The benefits of deconstructing how these toxins work on detailed level for potential chronic pain management and pharmacology.

Dr. Sam Robinson is a research fellow at the Institute for Molecular Biological Science at the University of Queensland in Australia. It took a walk on the beach and a jellyfish sighting to get his curiosity in gear for researching how toxins cause pain. He's focused on exploring painful toxins in a systematic way, down to the proteins and genetics involved. He adds that venom, for example, is not the same across different animals. Rather, there's a "whole cocktail of different toxins" with different uses, from capturing prey to self-defense, and they can affect different parts of the organism they bite.

While their similar functions come down to convergent evolution, there are a host of different ingredients. He gives several specific examples and explains why he's especially focused on toxins that affect our cellular voltage-gated sodium channels. That's where the stinging tree comes in. He's found that the tree injects a toxin that keeps those channels open, causing hours of pain. Furthermore, after the pain is gone, it can be revived by exposure to cold in a phenomena called cold allodynia, a condition chemotherapy patients also experience. This is the kind of connection that makes his research potentially applicable to numerous pain-related diseases and treatment.

Listen in for more examples of pain deconstructed.