MRC National Institute for Medical Research, London
Science for Health
Iris Salecker group
Axon guidance in the developing visual system of Drosophila
A defining feature of many brains areas in vertebrates and invertebrates is the organization of neuronal networks into columns and layers. In each of these units, afferent axons establish synaptic contacts with distinct sets of target neurons to ensure correct information processing in the mature brain. Our understanding of how such specific connections are formed during development is still limited. We use genetic and imaging approaches to study neural circuit assembly in the Drosophila visual system. Photoreceptor neurons extend axons from the retina into two areas of the optic lobe, the lamina and medulla, where they connect with target neurons in highly regular patterns. Visual circuit formation depends on intricate bidirectional interactions between photoreceptor axons, glia and target neurons.
Our ongoing studies aim at identifying the molecular determinants that control the initial development of neurons and glia in the optic lobe. Furthermore, we investigate the mechanisms that mediate layer-specific targeting of photoreceptor axons and their postsynaptic partners. As the molecular mechanisms are highly conserved, our studies will provide insights into the principles underlying normal brain development and, in the long term, associated neurological dysfunctions.
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In the adult visual system of Drosophila, R1-R6 photoreceptor axons terminate in the lamina, connecting with sets of lamina neurons within columns, while R7 and R8 axons establish connections with target neurons in two specific layers in the medulla.
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Photoreceptor axons (red) are in close contact with glial cells and their extensive processes (green) in the late pupal visual system.
Selected publications
- Chotard, C and Salecker, I (2007)
Glial cell development and function in the Drosophila visual system.
Neuron Glia Biology 3, 17-25 PubMed abstract - Bazigou, E; Apitz, H; Johansson, J; Lorén, CE; Hirst, EMA; Chen, P-L; Palmer, RH and Salecker, I (2007)
Anterograde Jelly belly and Alk receptor tyrosine kinase signaling mediates retinal axon targeting in Drosophila.
Cell 128, 961-75 PubMed abstract - Chotard, C; Leung, W and Salecker, I (2005)
glial cells missing and gcm2 cell autonomously regulate both glial and neuronal development in the visual system of Drosophila.
Neuron 48, 237-51 PubMed abstract
Our research themes
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