A new study sheds new light on the origins of modern brain cells. Researchers find evidence that specialized secretory cells found in placozoans, tiny sea creatures the size of a grain of sand, have many similarities to the neuron, such as the genes required to create a partial synapse. From an evolutionary point of view, early neurons might have started as something like these cells, eventually gaining the ability to create a complete synapse, form axons and dendrites and create ion channels that generate fast electrical signals — innovations which gave rise to the neuron in more complex animals such as jellyfish. Though the complete story of how the first neuron appeared remains to be told, the study demonstrates that the basic building blocks for our brain cells were forming in the ancestors of placozoans grazing inconspicuously in the shallow seas of Earth around 800 million years ago.