Sodium Channels Evolved Before Animals’ Nervous Systems, Research Shows

Posted on May 17, 2011 By Neuroscience News Electrophysiology, Neuroscience

An essential component of animal nervous systems—sodium channels—evolved prior to the evolution of those systems, researchers from The University of Texas at Austin have discovered.

“The first nervous systems appeared in jellyfish-like animals six hundred million years ago or so,” says Harold Zakon, professor of neurobiology, “and it was thought that sodium channels evolved around that time. We have now discovered that sodium channels were around well before nervous systems evolved.”

Zakon and his coauthors, Professor David Hillis and graduate student Benjamin Liebeskind, published their findings this week in PNAS.

Nervous systems and their component neuron cells were a key innovation in the evolution of animals, allowing for communication across vast distances between cells in the body and leading to sensory perception, behavior and the evolution of complex animal brains.

Sodium channels are an integral part of a neuron’s complex machinery. The channels are like floodgates lodged throughout a neuron’s levee-like cellular membrane. When the channels open, sodium floods through the membrane into the neuron, and this generates nerve impulses.

Zakon, Hillis and Liebeskind discovered the genes for such sodium channels hiding within an organism that isn’t even made of multiple cells, much less any neurons. The single-celled organism is a choanoflagellate, and it is distantly related to multi-cellular animals such as jellyfish and humans.

The researchers then constructed evolutionary trees, or phylogenies, showing the relationship of those genes in the single-celled choanoflagellate to multi-cellular animals, including jellyfish, sponges, flies and humans.

Because the sodium channel genes were found in choanoflagellates, the scientists propose that the genes originated not only before the advent of the nervous system, but even before the evolution of multicellularity itself.

“These genes were then co-opted by the nervous systems evolving in multi-cellular animals,” says Hillis, the Alfred W. Roark Centennial Professor in Natural Sciences. “This study shows how complex traits, such as the nervous system, can evolve gradually, often from parts that evolved for other purposes.”

“Evolutionarily novel organs do not spring up from nowhere,” adds Zakon, “but from pre-existing genes that were likely doing something else previously.”

Liebeskind, a graduate student in the university’s ecology, evolution and behavior program, is directing his next research efforts toward understanding what the sodium channels do in choanoflagellates.

Notes about this neuroscience research article

Contacts: Harold Zakon, Ben Liebeskind, David Hillis – University of Texas at Austin
Source: University of Texas at Austin press release

, , , , , ,

By Neuroscience News

Avatar of Neuroscience News Neuroscience News posts news from various labs, universities, hospitals and news departments around the world.

Neuroscience on Twitter

Neuroscience on Facebook

Neuroscience on Google+

Neuroscience News Posts

Please Share This Post

Google1DeliciousDiggGoogleStumbleuponRedditTechnoratiYahooBloggerRSS

16 Responses to Sodium Channels Evolved Before Animals’ Nervous Systems, Research Shows

  1. Rita May 27, 2011 at 7:49 pm

    Sodium Channels Evolved Before Animals’ Nervous Systems #neuroscience #neurology http://goo.gl/0yN3D

  2. Viren Ahluwalia May 23, 2011 at 1:15 am

    Sodium Channels Evolved Before Animals’ Nervous Systems #neuroscience #neurology http://goo.gl/0yN3D

  3. BIOLOGY May 22, 2011 at 8:01 pm

    Sodium Channels Evolved Before Animals’ Nervous Systems #neuroscience #neurology http://goo.gl/0yN3D

  5. ASPET May 18, 2011 at 1:08 pm

    RT @NeuroscienceNew: Sodium Channels Evolved Before Animals’ Nervous Systems #neuroscience #neurology http://goo.gl/0yN3D

  6. 神谷之康 / Y. Kamitani May 18, 2011 at 12:18 pm

    RT @NeuroscienceNew: Sodium Channels Evolved Before Animals’ Nervous Systems #neuroscience #neurology http://goo.gl/0yN3D

  7. IS Group May 18, 2011 at 11:49 am

    RT @NeuroscienceNew: Sodium Channels Evolved Before Animals’ Nervous Systems #neuroscience #neurology http://goo.gl/0yN3D

  8. D. Bunnell May 18, 2011 at 8:45 am

    RT @NeuroscienceNew: Sodium Channels Evolved Before Animals’ Nervous Systems #neuroscience #neurology http://goo.gl/0yN3D

  9. Carmen Rietdijk May 18, 2011 at 6:31 am

    RT @NeuroscienceNew: Sodium Channels Evolved Before Animals’ Nervous Systems #neuroscience #neurology http://goo.gl/0yN3D

  10. Sarah Kathryn Hannah May 18, 2011 at 5:12 am

    RT @NeuroscienceNew: Sodium Channels Evolved Before Animals’ Nervous Systems #neuroscience #neurology http://goo.gl/0yN3D

  11. Lina Jamis May 18, 2011 at 4:26 am

    > @NeuroscienceNew: Sodium Channels Evolved Before Animals’ Nervous Systems #neuroscience #neurology http://goo.gl/0yN3D

  12. ahmet uysal May 18, 2011 at 4:06 am

    RT @NeuroscienceNew: Sodium Channels Evolved Before Animals’ Nervous Systems #neuroscience #neurology http://goo.gl/0yN3D

  13. Peter Lovisek May 18, 2011 at 4:00 am

    RT @NeuroscienceNew: Sodium Channels Evolved Before Animals’ Nervous Systems #neuroscience #neurology http://goo.gl/0yN3D

  14. Nausheen Nayani May 18, 2011 at 3:59 am

    RT @NeuroscienceNew: Sodium Channels Evolved Before Animals’ Nervous Systems #neuroscience #neurology http://goo.gl/0yN3D

  15. Talya Grumberg May 18, 2011 at 3:58 am

    RT @NeuroscienceNew: Sodium Channels Evolved Before Animals’ Nervous Systems #neuroscience #neurology http://goo.gl/0yN3D

  16. Neuroscience News May 18, 2011 at 3:54 am

    Sodium Channels Evolved Before Animals’ Nervous Systems #neuroscience #neurology http://goo.gl/0yN3D

You must be logged in to post a comment Login