Current research interests
Our studies at the IBENS will continue to investigate the mechanisms by which diverse neuron-neuron and neuron-glia interactions orchestrate the assembly of layered and columnar visual circuit architecture. Our goal is to identify the underlying developmental steps at the cellular level with high resolution and to pinpoint the mechanistic basis by uncovering the responsible molecular determinants.
Focusing on neuron-neuron interactions, one line of our research addresses the question how individual higher-order neuron subtypes first choose their correct brain regions and then a synaptic layer within them. We focus on a specific projection neuron subtype in the medulla, that first decides not to innervate the lobula plate but to project into the lobula, where it then terminates in one specific synaptic layer. Results will provide insights into how guidance systems can sequentially control these two different decision-making processes in the same neuron subtype. The second project seeks to deepen our understanding of how neuron-neuron interactions mediate synaptic layer formation by segregation. We are therefore investigating the next steps of T4/T5 neuron development and their interactions with synaptic partner neurons in the lobula plate. Specifically, we aim to identify the molecular cascades linking subtype specification and adhesive interactions of their neurites during layer formation.
Continuing our studies focusing on neuron-glia interactions, a third project investigates how neurons shape the morphology of astrocyte-like glia and, conversely, how this glial subtype shapes synaptic connectivity and function in the developing and mature medulla. Building on our previous findings of Lapsyn, we implemented a strategy combining genetics and mass spectrometry to build a comprehensive picture of the membrane complexes and pathways, by which neurons influence the morphology of astrocytes. Furthermore, we are interested in the role of astrocytes in controlling circuit connectivity and function. Finally, a fourth project focuses on the question how glia controls developmental neurite remodeling to provide plasticity in setting up the correct layered and columnar organization of medulla neuron subtypes. Specifically, we seek to determine the relative roles of different glial subtypes in neurite remodeling, and to identify the underlying molecular mechanisms, that mediate this so far unexplored developmental step during visual circuit assembly.
