The cerebral cortex, a layer of neural tissue surrounding the cerebrum of the mammalian brain, has been known to play various roles in memory, language, thought, attention, and consciousness. Up until now, no invertebrate equivalent
to the cerebral cortex has been encountered, but Detlev Arendt, Raju Tomer, and colleagues may have found an evolutionary counterpart. The obvious answer is hidden in one simple creature– the worm. Wait, what? Yeah, you heard me. The marine ragworm, found at all water depths, has been shown to possess a tissue resembling that of our mysterious cerebral cortex.
Arendt and his colleagues used a technique called cellular profiling to determine a molecular footprint for each kind of cell in this particular type of ragworm. By utilizing this technique, they were able to uncover which genes were turned on and off in each cell, providing a means for cellular categorization. Surprisingly, mushroom bodies, regions of the ragworm’s brain that are thought to control olfactory senses, show a striking similarity to tissue found in our cerebral cortex. This intriguing discovery may provide remarkable insight into the evolutionary basis of what has developed into an incredibly important cerebral structure.
Read more about this review here, or see the original article in Cell.