The Brienomyrus brachyistius, a fish commonly referred to as baby whales, uses electrical charges to communicate with and sense the world around them.
Understanding how these African fish create electrical discharges could help researchers find new treatments for epilepsy.
Photo Credit: Univ. of Michigan
“Nerve impulses typically last one millisecond, but the baby whale and other related weakly electric fish make extremely brief discharges of less than a few tenths of a millisecond. That means that the ion channels of their electric organs must open and close especially rapidly. By studying the molecular structure and biophysical properties of the ion channels of their electric organ we are discovering how their channels evolved these exceptional properties. This gives us insights into the general properties of our own ion channels,” Harold Zakon, a professor in the departments of Integrative Biology and Neuroscience at the University of Texas at Austin, explained to ALN.
The bioelectric security system used by baby whales allows the fish to create brief electrical flashes, some of which last less than a tenth of a thousandth of a second. This quick communication system also allows the fish to avoid the detection systems of their natural predator, the catfish.
The electricity is produced in a specialized organ near the tail. This organ contains a protein, KCNA7, that also exists in the hearts and muscles in humans.
New research, published in the journal Current Biology, identified a negatively charged patch in the KCNA7 protein that control the quickness of the electrical flashes.
Image caption: Image of Brienomyrus brachyistius, exemplifying the 'short discharge' fish in our study. Image by JR Gallant for Michigan State University
This discovery could shed light on how these same electrical pathways operate in conditions like epilepsy, migraines, and even some heart conditions.
In people with epilepsy, electrical pulses in the brain cause seizures.
“Our work is basic research so the implications for human health are indirect. As with all health-related research, unless you understand how something works, you can’t understand how it is broken,” Zakon said.
“That electric fish are not a usual animal model like fruit flies, zebrafish or mice. Sometimes, by studying an animal that is unique and unusual in some way—such as electric fish are—we can see things that are not obvious in the more commonly used model animals.”
Source for above: ALN mag
Source for Below: laboratoryequipment.com From University of Texas Austin
Fish’s Use of Electricity Might Shed Light on Human Illnesses
Deep in the night in muddy African rivers, a fish uses electrical charges to sense the world around it and communicate with other members of its species. Signaling in electrical spurts that last only a few tenths of a thousandth of a second allows the fish to navigate without letting predators know it is there.
Now scientists have found that the evolutionary trick these fish use to make such brief discharges could provide new insights, with a bearing on treatments for diseases such as epilepsy.
Scientists led by a team at The University of Texas at Austin and Michigan State University outlined how some fish, commonly referred to as baby whales, have developed a unique bioelectric security system. This security system lets them produce incredibly fast and short pulses of electricity so they can communicate without jamming one another’s signals, while also eluding the highly sensitive electric detection systems of predatory catfish.
In a specialized electric organ near the tail, weakly electric fish, like the baby whales, possess a protein that also exists in the hearts and muscles of humans.
The electrical pulses generated through this protein, called the KCNA7 potassium ion channel, last just a few tenths of a thousandth of a second, and some electric fish have adapted to discriminate between timing differences in electrical discharges of less than 10 millionths 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,” Harold Zakon, a professor in the departments of Integrative Biology and Neuroscience, said.
The team identified a negatively charged patch in the KCNA7 protein that allows the channel in the electric fish to open quickly and be more sensitive to voltage, allowing for the extremely brief discharges.
Scientists have learned that the electrical signals these fish use and how they evolved may help humans in the future by shedding light on how those same electrical pathways operate in conditions such as epilepsy, where electrical pulses in the brain and muscles cause seizures.
The finding may also have implications for discoveries about 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,” Swapna Immani, first author of the paper and a research associate in neuroscience and integrative biology, said. “So understanding what controls the sensitivity of potassium channels to stimuli is important for health as well as a basic understanding of ion channels.”
Previous understanding of the same protein was based on potassium channels in fruit flies, but researchers say this paper suggests that the particular region with the negative patch might function differently in vertebrates.
Looking at the evolution of the specialized electric organ also can provide important windows into how genes change and express themselves. By studying unique or extreme abilities in the animal kingdom, much can be learned about the genetic basis of adaptations, the paper says.
“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,” Jason Gallant, assistant professor of integrative biology at Michigan State University and a researcher on the project, said. “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.”
