Errors in neuronal proteins lead to disease. It is important to study structures of these proteins in as native a context as possible that can be examined in a way that can recreate potential disease states, i.e. in genetically modified or patient-isolated systems.
Focused ion beam milling combined with electron cryo-tomography (cryoET) has the ability to unravel the molecular details of processes within cells and tissues, ultimately leading to an understanding of how changes in the structures of macromolecules in their native context impact on cellular function.
The axonal initial segment (AIS) is a distinct region of the axon directly after the cell body through which vesicles must pass in order to continue down the neuronal axon. Key to maintaining proper AIS function is the microtubule network within the axon. Defects in cytoskeletal organisation within the AIS have been implicated in disease and understanding the arrangement of the cytoskeleton and the structure of components is important for understanding the maintenance of proper AIS function.
The formation of neuropathic phenotypes in-situ is poorly understood. We are developing approaches to investigate the morphological and structural changes that occur within brain tissues during the development and onset of neurodegenerative disease using cryoET. The formation of inclusion bodies and neurofibrillary tangles is a well-known and prominent feature of late-stage disease; however, we aim to understand the molecular changes that occur in proteins that give rise to these features at different stages of disease in-situ.
The project is separated into two areas of interest:
i) The use of human iPSC-derived organoids to study the impact of mutations on the molecular plasticity of axonal transmission and cytoskeletal transport.
ii) Imaging molecular changes in brain ultrastructure using neurodegenerative models of isolated mouse brain sections.
Contact the team
Principal scientist: Dr Michael Grange – Michael.Grange@rfi.ac.uk