High Cell Diversity and Complex Peptidergic Signaling Underlie Placozoan Behavior (Current Biology)

Placozoans are simple flat animals that lack a nervous system and muscles. Varoqueaux et al. find that the behavior of the placozoan Trichoplax is influenced by complex chemical signaling. Neuropeptides, secreted molecules produced by neurons in other animals, induce striking changes in the behavior of these neuron-less animals.