A study conducted by the Barcelona Center for Genomic Regulation uncovers the origin of neurons in complex animals through the analysis of placozoans, marine animals of approximately one millimeter in size.

Placozoans are tiny creatures that feed on algae and microorganisms, and they dwell on the surface of rocks in warm and shallow seas. Despite being very simple animals lacking body parts or organs, placozoans are one of the five major animal lineages on Earth, along with ctenophores, sponges, cnidarians (corals, sea anemones, and jellyfish), and bilaterians (including humans).

In the study, scientists used molecular techniques and computational models to understand how different types of cells in placozoans evolved. They discovered that the nine major cell types in placozoans seem to be interconnected by peptidergic cells, a type of cell that releases peptides and coordinates the behavior of these simple animals.

This finding suggests that neurons and peptidergic cells may have evolved from a common ancestor in more complex animals. These cells are vital for the movement, feeding, and response of placozoans, despite their structural simplicity.

The study provides a clearer understanding of the evolution of nerve cells and how they developed in more complex animals over time. These findings are significant for better understanding the diversity and complexity of living organisms and their evolutionary relationship.

– Barcelona Center for Genomic Regulation (CRG)