Did you know that electric fishes evolved independently two times: one lineage in Africa and one in South America? I didn’t know that either until I went to the great talk from Harold Zakon which he gave yesterday in the Bernstein Centre for theoretical Neuorsciences Berlin. Interestingly both lineages have fishes which communicate via electric waves and fishes which use electric pulses instead. What is the molecular basis for that difference in electronic mechanism? Which channel mutation lead from continuous waves to short pulses? For the African lineage, Zakon and his coworkers were able to show that the transition from electric wave to electric pulse was based on a mutation in the voltage gated potassium channel. The insertion of negative Aminoacids in the top of the channel (S3-S4 linker) leads to an increased voltage sensitivity (faster and earlier opening of the ion channel) which results in a shortening of the electric signal (the action potential). What I liked a lot, is the fact that such a sort of mutation (change the polarity of the ion channel to make it more voltage sensitive) is also found in other species. Zakon told us that for example in sharks there is a mutation of positive Aminoacids in the bottom of a Calcium channel which also leads to an increased voltage sensitivity and shapes the electro-sensation of sharks. See for example:
"Regulation and modulation of electric waveforms in gymnotiform electric fish." Stoddard, Philip K., et al. Journal of Comparative Physiology A 192.6 (2006): 613-624.
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IdeaI love to increase my general science knowledge by reading papers from different fields of science. Here I share some of them. Archiv
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