Helena Barr is a Ph.D. candidate in the Program in Neuroscience at Harvard University and defended her thesis in September 2025. Helena joined this program with a strong research background, having both a Masters in Neuroscience from McGill University as well as three years of experience as a research technician at the University of Colorado Medical School. During her Ph.D., Helena gained considerable expertise in neuroimmunology and bioinformatics. She has systematically characterized the function and regulation of brain border-associated macrophages (BAMs), a small population of immune cells in the brain, using a combination of flow cytometry, functional assays, single-cell and bulk RNA sequencing, and cell type-specific genetic knockouts. Notably, she has found that these cells actively engulf amyloid beta in mouse models of Alzheimer’s Disease (AD), has identified a highly evolutionarily-conserved receptor they use to take up this peptide, and has shown that BAM perturbation worsens brain border amyloid pathology. In her postdoctoral training with Dr. Beth Stevens, Helena plans to build on the translational relevance of her work by seeking to improve amyloid beta engulfment by BAMs. She aims to study this both in traditional mouse models of AD and in novel human BAM models that she has developed in collaboration with another postdoctoral fellow in the lab. Her experimental goals include a small-molecule screen for regulators of the BAM receptor involved in amyloid-beta engulfment, CRISPR-mediated overexpression of the receptor in mouse models of AD with an engineered innate immune system, and high-throughput functional assays of BAM engulfment both in vivo and in vitro.