The Evolution of Axonal Excitozones
Author Information
Author(s): Hill Alexis S., Nishino Atsuo, Nakajo Koichi, Zhang Giuxin, Fineman Jaime R., Selzer Michael E., Okamura Yasushi, Cooper Edward C.
Primary Institution: University of Pennsylvania
Hypothesis
How did the mechanisms underlying ion channel clustering evolve in early chordates?
Conclusion
The study concludes that the clustering of sodium channels on axons was a pivotal innovation in early chordates, essential for the evolution of complex neural signaling.
Supporting Evidence
- Sodium channel clustering evolved early in the chordate lineage, before the divergence of the earliest wormlike and planktonic groups.
- Nerve fibers of the lamprey, a primitive fish, retained some invertebrate features but possessed dense sodium channel clusters.
- A potassium channel clustering system evolved after the divergence of lampreys, in a common ancestor of sharks and humans.
- The clustering of sodium channels on axons was the initial pivotal step in a chordate-specific series of evolutionary innovations.
Takeaway
This study shows that early chordates developed special ways to group important proteins that help send signals in their nervous systems, which was crucial for their survival and evolution.
Methodology
The researchers analyzed genomes of primitive chordates and studied the cellular distribution and functional properties of their ion channels.
Digital Object Identifier (DOI)
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