Topic：Understanding Neurodegeneration Using Cryo-Electron Microscopy, 4D-STEM and Ptychography

Speaker：Prof. Henning Stahlberg

Host：Prof. Maofu Liao

Time：October 18th.15:00-16:30pm

Venue：Room 111,Lynn Library 

Abstract:

Cryo-transmission electron microscopy (cryo-EM) or tomography (cryo-ET) of frozen hydrated specimens is an efficient technique for analyzing the structure of proteins or tissue sections. Here, we study human brain from patients who died from Parkinson’s disease or Alzheimer’s disease, using high-pressure freezing, sectioning and cryo-ET. We also study alpha-synuclein fibrils, which is the protein underlying Parkinson’s disease, multiple system atrophy (MSA) and Dementia with Lewy bodies (DLB). Different fibril polymorphs will be presented and their potential impact on intracellular neurodegeneration mechanisms discussed.

Cryo-EM and cryo-ET suffer from their low signal-to-noise ratio. Contrast of cryo-EM can be improved through diffractive imaging. We have developed a 4D-scanning transmission electron microscopy approach with parallax or ptychography data processing, using an aberration-corrected Titan Krios. This 4D-STEM approach shows improved contrast of cryo-EM images. In addition, recent results with stroboscopic single electron illumination to reduce beam damage will also be presented.

Introduction:

Prof. Dr.Henning Stahlberg Full Professor of Physics at the Ecole Polytechnique Federale de Lausanne(EPFL) holding multiple other positions. His research focuses on high-resolution cryo-electron microscopy techniques used to study neurodegenerative diseases and other protein systems. Professor Stahlberg has made significant contributions in the development of electron microscopy hardware and applications,sample preparation,data collection schemes,and data analysis software systems.His team has utilized cryo-electron microscopy to study brain tissue from patients with Parkinson's disease and other neurodegenerative conditions,achieving notable successes in protein sample preparation,data processing.and structural resolution. Moreover,he is committed toeducation and training,supervising PhD students,andteaching in varlous academic courses.