Architecture and functions of axonal actin revealed by targeted cellular manipulations and advanced microscopy approaches

At NeuroCyto, we are neuronal cell biologists: we want to understand how neurons are organized at the cellular level. How do they differentiate, then build and maintain their complex arborization? How do they establish and conserve their polarity, with the axon and dendrites allowing to send and receive signals? We apply advanced microscopy techniques (live-cell imaging, super-resolution microscopy) to directly observe molecular assemblies in neurons, revealing how they organize and shape its physiology. Our work is currently focusing on the organization of actin, one of the main cytoskeleton components, along axons. Several new axonal actin structures have been discovered by us and others, including submembrane actin rings and intra-axonal actin hotspots and trails (see attached preprint article, Papandréou & Leterrier 2018). We want to understand the molecular architecture and functions of these structures, and their relevance for physiological processes such as axonal transport and proper functioning of presynaptic boutons. To do so, we take advantage of the beautiful model of hippocampal neurons in low-density culture, so we can visualize the intricate morphology of individual neurons and follow their axons. The team currently has six members, and we welcome trainees all year long. interested students are welcome to contact us and discuss about potential masters project (3 to 6 months). As an example, current and future projects include:
• Manipulating actin and its molecular partners in cultured neurons using expression of small interfering RNAs (RNAi) by engineered viral constructs.
• Validating new multi-color super-resolution microscopy modalities for observing 2-5 components of the axonal cytoskeleton at once down to a few tens of nanometers.
• Developing and testing new approaches to couple super-resolution microscopy to electron microscopy.
• Studying the role of actin in the formation and maintenance of presynapses.

Share the offer on :