Some fish use electrical charges to sense the world around them while communicating with other members of its species, according to the researchers. The electrical signals only last a few tenths of a thousandth of a second to let fish navigate muddy waters at night without alerting predators. Researchers are now using that natural occurrence of brief discharges to give a new perspective on treating different diseases.
The fish, known as baby whales, have a bioelectric security system that creates fast and short pulses of electricity that allows them to communicate without blocking another fish’s signal. Electric fish use a special electric organ near the tail that contains a protein found in the hearts and muscles of humans. The protein, called the KCNA7 potassium ion channel, generates electrical pulses that last a few tenths of a thousandth of a second.
“Most fish cannot detect electric fields, but catfish sense them. The briefer electric fish can make their electric pulse, the more difficult it is for catfish to track them,” said Harold Zakon, a professor in the departments of Integrative Biology and Neuroscience, in a press release.
The University of Texas researchers figured out that a negatively charged patch in the KCNA7 protein allows the channel in the electric fish to quickly open and become more sensitive to voltage to create brief discharges. They also learned that the electrical signals and how they have evolved could help humans by showing how the same electrical pathways operate in conditions like epilepsy, which occurs when electrical pulses in the brain and muscles can cause seizures. The researchers suggest that it could also help with discoveries for migraines and some heart conditions.
“Mutations in potassium channels that make them too sensitive or not sensitive enough to electrical stimuli can lead to epilepsy or cardiac and muscle diseases,” said Swapna Immani, first author of the paper and a research associate in neuroscience and integrative biology. “So understanding what controls the sensitivity of potassium channels to stimuli is important for health as well as a basic understanding of ion channels.”
The researchers suggest that the evolutions of the specialized electric organ can also help study how genes change and express themselves.
“The take-home message of our project is that strange animals like weakly electric fish can give very deep insights into nature, sometimes with important biomedical consequences,” said Jason Gallant, assistant professor of integrative biology at Michigan State University and a researcher on the project. “We discovered something at first blush that would seem like an idiosyncrasy of the biology of electric fish, which is always exciting but lacks broad applicability. Because of the relaxed evolutionary constraints on this important potassium channel in electric fish, which don’t have to follow the same rules normally imposed by nervous system or muscle, the tinkering of natural selection has revealed a physical ‘rule’ that we suspect governs potassium channels more broadly.”
The research was published in the journal Current Biology and was funded by the National Science Foundation and the National Institutes of Health.