Nature: Sponge cells suggest the origin of the nervous system

Sponges are simple creatures, but they are professional filter feeders, filtering thousands of liters of water through their bodies every day to collect food

A study published in the journal Science on November 4 revealed that sponges use a complex cell communication system to regulate their feeding and potentially eliminate invading bacteria

Spongy fossils may be the earliest known animals on earth

Cells often communicate with each other, and neurons transmit electrical or chemical signals through tiny, targeted synaptic connections

In order to discover which cells express these genes, evolutionary biologist Detlev Arendt of the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany, and his colleagues analyzed different cells of a freshwater sponge (lake sponge).

They found that this sponge has 18 different cell types

The researchers then used X-ray imaging and electron microscopy to study one of these cell types, which they call secretory nerve cells

Electron microscopy shows that nerve cells (purple and red) can extend their arms to communicate with digestive cells (blue, green and yellow)

Pioneer of the nervous system

The expression of the two cell types and genes that are getting closer may allow the secreted chemicals.

Some scientists say it is far-fetched to call these cells the precursors of the nervous system

April Hill, a developmental geneticist at Bates College in Lewiston, Maine, hopes that scientists will use this research and its methods as a way to further study this ubiquitous sponge.