PROTOBRAIN · Sensory-motor circuits in marine zooplankton and early evolution of the nervous system

Animal nervous systems evolved in a marine environment at the dawn ofanimal life, and diversified during the Cambrian explosion', one of themost spectacular events in the history of life. Remarkably little isknown about early stages of the evolution of neuronal circuits andnervous systems. Simple marine planktonic organisms, in particularciliated larvae of various marine invertebrates, can give us insightsinto how simple nervous circuits of marine organism function and mayhave evolved. The proposed project aims at investigating the nervoussystem of ciliated animal larvae using an integrative approach combiningthe fields of molecular biology, neurobiology, behaviour, marine ecologyand evolution. As such, the project aims at pioneering an entirely newfield of interdisciplinary investigations, the neurobiology of marinezooplankton. We will use a cultured marine annelid as our main modelspecies, and several 'satellite' species to give a comparativeperspective to our investigations. Our objective is to understand theanatomy and function of neuronal circuits that regulate the planktonicmigration of ciliated zooplankton larvae. We will be able to addressthis at various levels, linking molecules to neuron types, neurons tolarval behaviours and behaviours to marine ecology. Our aim is to getthe first detailed systems level understanding of the nervous system ofa marine ciliated larva.