title: Three-dimensional structural changes in living hippocampal neurons imaged using magnetic AC mode atomic force microscopy.
abstract: We developed the magnetic AC (MAC) mode atomic force microscopy (AFM) to image the 3D ultrastructure of living hippocampal neurons under physiological conditions. Initially, the soma, the dendrites and the growth cones of hippocampal neurons were imaged. The imaging force was adjusted to a small value for the long-term observation. The neural spines were damaged when the tip produced a large force; the spines regenerated after the force was reduced. Subsequently, we explored the relationship between structural changes in hippocampal neurons and Alzheimer's disease by employing the new imaging technique. Time-lapse image acquisition (10 min intervals) showed that the growth cone collapsed after the addition amyloid peptide fragment beta(25-35), which is thought to initiate Alzheimer's disease. In addition, we found substantial changes in mechanical properties and in the volume of individual growth cone. This study suggested that MAC mode AFM may be a powerful tool for observing long-term structural changes in living neural cells under physiological conditions.
authors.affiliation: The Key Laboratory of Atomic and Molecular Nanosciences of Education Ministry, Department of Physics, Tsinghua University Zhongguancun, Beijing 100084, China.
authors.forename: Sun
authors.initials: S
authors.lastname: Yunxu
authors.forename: Lin
authors.initials: L
authors.lastname: Danying
authors.forename: Rui
authors.initials: R
authors.lastname: Yanfang
authors.forename: Han
authors.initials: H
authors.lastname: Dong
authors.forename: Ma
authors.initials: M
authors.lastname: Wanyun
mesh_terms: D016229:Amyloid beta-Peptides / Q000494:pharmacology; D000818:Animals; D002478:Cells, Cultured; D006624:Hippocampus / Q000166:cytology; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008280:Magnetics; D018625:Microscopy, Atomic Force / Q000379:methods*; D009474:Neurons / Q000187:drug effects / Q000648:ultrastructure*; D010446:Peptide Fragments / Q000494:pharmacology; D051381:Rats
chemical_list: D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; C074636:amyloid beta-protein (25-35)