Dr. Pramod Dash
Dr. Pramod Dash
Neal Waxham, Ph.D.
Neal Waxham, Ph.D.

Two McGovern Medical School faculty members contributed to research now published in the Public Library of Science (PLOS) Biology Journal, as part of a first-authored paper written by UTHealth Graduate School of Biomedical Sciences alumna Tara Fischer, Ph.D.

Neal Waxham, Ph.D., the William M. Wheless III Professor in Biomedical Sciences in the Department of Neurobiology & Anatomy, and Pramod Dash, Ph.D., interim chair of the department and the Nina and Michael Zilkha Distinguished Chair in Neurodegenerative Disease Research, assisted in the research titled “Morphology of mitochondria in spatially restricted axons revealed by cryo-electron tomography.”

The team investigated how neurons project nerve fibers called axons to local and distal sites and can display heterogeneous morphologies with limited physical dimensions that may influence the structure of large organelles such as mitochondria. Using cryo-electron tomography (cryo-ET), this study characterized native environments within axons and presynaptic varicosities to examine whether spatial restrictions within these compartments influence the form and structure of mitochondria.

These findings offer new perspectives on the influence of physical and spatial characteristics of cellular environments on mitochondrial morphology and highlight the potential for remarkable structural plasticity of mitochondria to adapt to spatial restrictions within axons.

“The results in this manuscript were made possible by the remarkable advancements in cryo-electron microscopy and in particular cryo-electron tomography over the past two decades. UTHealth has invested heavily in this state-of-the-art technology and we have and continue to benefit from this long-term investment,” Waxham said. “This manuscript is an excellent example of how new technology in the hands of a bright and talented student like Tara, can bring novel insights into basic mechanisms of cell biology. In this case, the remarkable structural plasticity in mitochondria within axons was revealed that challenges existing ideas about how they are transported to distant synapses.”

Fischer was affiliated with the GSBS Program in Neuroscience and graduated in 2017. She was also a recipient of a Ruth L. Kirschstein National Research Service Award Individual Predoctoral Fellowship from the National Institutes of Health (F31).

“Since our work is relevant to a range of fields, including mitochondrial biology, neurobiology, and axonal transport and development, PLOS Biology offers a unique platform to disseminate our findings to a large audience,” Fischer said. “Additionally, PLOS Biology is open-access, meaning that our work can also reach interested audiences beyond academia and without the limitation of institutional subscriptions.”

In addition to her NIH F31 award, she received several GSBS honors including the Dee S. and Patricia Osborne Endowed Scholarship in the Neurosciences (2015), Sam Taub and Beatrice Burton Endowed Scholarship in Vision Disease (2015), and Presidents’ Research Scholarship (2017).

Currently, Fischer is a postdoctoral fellow in the lab of Richard Youle, Ph.D., at the National Institute of Neurological Disorders and Stroke (NINDS) in Bethesda, Maryland.