Poster abstracts
Poster number 66 submitted by Chao Sun
Immediate induction of varicosities by transverse compression but not uniaxial stretch in axon mechanosensation
Chao Sun (MCDB, The Ohio State University), Lin Qi (Department of Biomedical Engineering, The Ohio State University), Yang Cheng (Department of Biomedical Engineering, The Ohio State University), Yi Zhao (Department of Biomedical Engineering, The Ohio State University), Chen Gu (Department of Biological Chemistry and Pharmacology, The Ohio State University)
Abstract:
Mild traumatic injury (mTBI) in mice damages axons and results in axonal varicosities, which manifest as bead-like swelling of the axonal shaft and can impede signal transduction. This study aimed to assess how the orientation of mechanical shock affects the quantity of axonal varicosities. Using Thy1-YFP transgenic mice, we visualized axonal varicosities in CHIMERA, a mouse model that mimics mild traumatic injury. Our results also show that axonal varicosities predate microglia activation to be the earliest known event for axonal injury. We found that axons perpendicular to the direction of the CHIMERA impact are more prone to varicosities than those parallel to the direction of impact, suggesting that transverse compression is more efficient than lateral compression when inducing axonal varicosities. Additionally, in cultured neurons, we found that axonal varicosities were more likely to be induced by transverse compression from a fluid puffing test than uniaxial strain from a nanowrinkle stretch assay. The finding provides insight for the better understanding of axonal mechanosensation. Potentially, clinicians can pay more attention to the impact direction in which a human patient receives a concussion and its effects to the tissue damage.
Keywords: Axonal varicosities, Traumatic brain injury, Mechanosensation