We are interested in the molecular mechanisms underlying the establishment of neural connectivity during development and its maintenance at later stages in life. The correct formation of connections is fundamental issue during brain development. Accuracy of these events is critical for the correct functioning of the brain, including processes involved in memory, learning, perception and behaviour. Our research focuses on genes involved in the control of axon pathfinding and the formation of synaptic interactions between specific subpopulations of neurons. We use mainly the vertebrate visual system as a model (mouse and zebrafish) with its highly regular arrangement of specific subsets of neurons and the generation of defined orderly circuits either within the retina or axon projections from the eye to different brain targets. In order to measure functionality of connections we perform in vivo functional imaging in zebrafish larvae. In parallel, we also work on the synaptic arrangements in the mouse retina and hippocampus. We believe that our general understanding of circuit assembly and maintenance will give us also important insights into the molecular processes linked to psychological disorders.