about the episode
Comb jellyfish are gorgeous transparent sea creatures that have been swimming in our oceans for 600 million years. Its eight long, thin, comb-like ribs can glow with beautiful colours. Whatever they have? A strange nervous system, now properly depicted for the first time.
Our nervous system is made up of individual cells that communicate with each other via synapses: the connection points where signals can travel from one cell to another. The idea has long been that only one design featured in evolution, which was the blueprint for the nervous systems of all animals living today. Except for the comb jellyfish.
It was already known that the animal deviates in this regard, but studying the nervous system of these small and vulnerable marine animals has simply proven too difficult. Using a 3-D electron microscope, the researchers have now succeeded in imaging it in day-old American comb jelly.
The comb jellyfish has a nervous system that is not made up of individual neurons, but rather compact networks of neurons. It is possible, but not yet confirmed, that this is evidence of more than one blueprint for the nervous system. But more research is definitely needed. If only because it is not known how signals can be transmitted in such a network without synapses.
Read more here: The discovery challenges our understanding of nervous systems and their evolution.
