Associate Professor of Anatomy and Neurobiology and Associate of the Sanders-Brown Research Center on Aging. The research of Dr. Geddes examines mechanisms involved in cytoskeletal disruption following neurotrauma and in neurodegenerative disorders. The cytoskeleton is essential for neuronal function and disruption of the cytoskeleton is an early marker of neuronal injury.
Cytoskeletal proteins are sensitive substrates of calpains, caspases and other proteases.
Recent results suggest that cytoskeletal proteins not only serve a structural role, but are also involved in signal transduction. In the neurofibrillary tangles found in Alzheimer's disease, the normal cytoskeleton is severely disrupted, replaced by paired helical filaments. These are composed of a microtubule-associated protein, tau, which has become hyperphosphorylated. Many other cytoskeletal proteins are lost from tangle-bearing neurons. Current research utilizes in vivo and in vitro models to examine the mechanisms involved in the cytoskeletal disruption and neuronal death associated with Alzheimer's disease.