BME Summer Seminar Series
Wednesday, July 6th, 2022
9:30-10:30AM EST
Via Zoom Meeting – link below*
Evaluation links:
Agnes Doszpoly:
https://purdue.ca1.qualtrics.com/jfe/form/SV_03woaH29QUpxMdU
Zachary Davis:
https://purdue.ca1.qualtrics.com/jfe/form/SV_8iW9vF9NzocSnae
Calcium-dependent CaMKII Signaling and the Regulation of Actin Filaments of Dendritic Spines in Alzheimer’s Disease
Agnes Doszpoly (D. Umulis/T. Kinzer-Ursem, advisor)
Abstract: Alzheimer’s Disease (AD) is a neurodegenerative condition that results in a significant loss of neuronal connection in the hippocampus, as well as overall brain mass from onset of disease. There
are currently no effective treatments available for diagnosed patients as AD is the 7th leading cause of death in the USA. One hypothesized underlying condition of AD is the loss of synaptic plasticity, the major mechanism by which neurons function
and develop cognitive memories in the hippocampus. Glutamatergic neurons receive excitatory input located at specialized post-synaptic compartments called dendritic spines. Calcium (Ca2+) signaling has been shown to induce dynamic changes in neuronal
activity of these dendritic spines. Though many Ca2+ -dependent protein signaling mechanisms have been identified, including that of Calmodulin dependent kinase II (CaMKII), their relative contributions to dendrite morphology via actin polymerization
are not well understood. This project aims to investigate how Ca2+/CaMKII signaling controls actin organization and dendritic spine regulation
in vivo in a mouse model of AD. It will also aim to optimize a neuronal culture technique for stabilizing dendritic spines prior to imaging. Long-term project goals include developing a super-resolution microscopy to image CaMKIIb/actin interactions
and compare data with computational model outputs to produce quantifiable results. Overall, the work aims to identify pharmaceutical targets for developing treatments for AD patients.
MRI to determine interface mechanics in soft tissue
Zachary Davis (Deva Chan, advisor)
Abstract: Articular cartilage is a soft-tissue that covers the ends of bones and lubricates motion within the joints. Defects in the articular cartilage affect almost 1 million Americans per year and can
lead to major disabilities such as osteoarthritis. Many of the surgical interventions to repair these defects include implants that contain cells, tissue, healing agents, and other factors to restore biochemical content and mechanical function throughout its
depth. It is necessary to confirm that both mechanical function and biochemical content are restored through both benchtop and in vivo tests. For confirming mechanical integration on the benchtop, a pushout test is used to determine the failure force of a
suspended repair defect. However, this method cannot be used in vivo since it is destructive. An MRI method called displacement encoding with stimulated echoes (DENSE) has been used to look at strain responses to physiological loads non-invasively. DENSE has
been used to look at cartilage mechanics in vivo, in situ, and in vitro. The next stage in developing DENSE for repair applications is to optimize the post-processing to look at the interface, or the area where the repair fill meets with native cartilage.
Currently, we are developing an MRI safe loading device to apply cyclic loads within an MRI to be run in sync with the DENSE sequence. We will make gels that contain different stiffness ratio of “native” to “repair” portions to create a mechanical interface
similar to ones used in repairs. Image processing pipelines will be tested to determine the optimal pathway to view the interface. Non-invasively determining the strains at an interface can be used to evaluate the mechanical integration not only in cartilage,
but in other soft tissues as well.
*Join Zoom Meeting
https://purdue-edu.zoom.us/j/92168739019?pwd=cnBOaFBxN3FWVVVTWC8wWWhaekdIdz09
Meeting ID: 921 6873 9019
Passcode: biomedical
Liz Rowen
She/Her
Graduate Program Assistant
Weldon School of Biomedical Engineering
Martin C. Jischke Hall of Biomedical Engineering
206 S. Martin Jischke Drive
West Lafayette, IN 47907-2032
o: 765-494-1197
