Name: Alena Leitman
Field of study: Cell Biology
Host institution: Marine Biological Laboratory, Woods Hole, MA
Mentor(s): Dr. Scott Brady
The microtubule-associated protein (MAP) tau is involved in microtubule dynamics and maintenance. Insoluble filamentous tau aggregates are a hallmark of a number of neurodegenerative diseases: argyrophillic grain dementia, Down's syndrome, frontotemporal dementia or Pick's disease, and progressive supranuclear palsy to name a few. One of the most common adult-onset tauopathies, accounting for 50-60% of all cases, is Alzheimer's disease (AD). Worldwide, over 20 million people are affected by AD, including 10% of people over 65 years old and 50% of those over 85. The most well-known hallmark of AD is the formation and accumulation of neurofibrillary tangles - paired helical filaments containing tau. Neurons of hippocampus and frontal cortex, affected in AD, exhibit loss of function in the distal axon and mislocalization of membrane-bound organelles (MBOs), which suggest that intracellular axonal transport is disrupted. Given this correlation, we assessed the biological effects of filamentous tau on microtubule-dependent fast axonal transport (FAT) using isolated squid axoplasm.