Evolutionary NeurobiologyGáspár Jékely

We reconstruct and study whole-body neural circuits in marine invertebrate larvae to understand the control of movements and the evolution of nervous systems.

Research Overview

We are interested in the neural circuit bases of behaviour and how neuromodulators confer flexibility to circuit activity and behaviours. Our aim is to study this at the single neuron level and for entiry neural circuits. This requres the mapping of circuits at synaptic resolution and the mapping of neuromodulators and their receptors to single neurons. Achieving this at cellular resolution in an entire nervous system is only possible by studying small animals that are also amenable to experimental manipulations. We study larval stages of the marine annelid Platynereis dumerilii to understand contextual neuromodulation in fully mapped, stereotypical circuits, and its changes during development. Since several modulators and their receptors found in Platynereis are conserved across bilaterians, including humans, the principles and mechanisms we uncover in the simple and tractable annelid nervous system may inform us about similar processes in more complex brains.



We use whole-body connectomics and overlay neuromodulatory networks with single-cell resolution onto synaptic connectomes. We complement this with circuit-wide activity imaging, behavioural analysis, and neurogenetics to study how the sensory environment and the modulatory landscape influences circuit activity. Genome editing and transgenic access to single neurons in Platynereis allow us to link the network output to molecular function at the synapse. We hope to uncover how neuronal circuits coordinate body-wide circuit activity and behaviour and how neuromodulatory signals contribute to flexibility.

Scanning electron micrograph of a Platynereis dumerilii larva
All cells in a Platynereis larva reconstructed by volume electron microscopy.