Lab Members

Current lab members

Leire Abalde-Atristain

Leire Abalde-Atristain, Ph.D.
Postdoctoral Fellow

Born in the beautiful town of San Sebastian in the Basque Country (Northern Spain), Leire received her B.Sc. in Biotechnology from the Autonomous University of Barcelona, and her M.Sc. in Biomedical Research from the Pompeu Fabra University in Barcelona. Sponsored by the Spanish predoctoral La Caixa Fellowship, she then obtained a Ph.D. from the Johns Hopkins University, where she investigated the molecular mechanisms underlying neuron survival and death under the guidance of Ted and Valina Dawson. Leire joined the Freeman lab in late 2019 to pursue her interest in the signals injured neurons send to elicit a response in glia.

Adel Avetisyan

Adel Avetisyan, Ph.D.
Postdoctoral Fellow

Adel completed her Ph.D. at the lab of Professor Adi Salzberg, Rappaport Faculty of Medicine, Technion — Israel Institute of Technology. During her graduate studies she worked on the programmed cell death and cell-fate determination processes that take place during the development of Drosophila chordotonal organs. Adel joined the Freeman lab in 2018 to study the molecular mechanisms underlying axonal degeneration.

Romina Barria

Romina Barria, M.S.
Senior Research Associate

Romina studied Biochemistry at the University of Chile, earning a B.S degree in 2003 and an M.S. in 2006, exploring the role of the S97N domain of Dlg in synapse development in Drosophila melanogaster. She then joined the laboratory of Dr. Vivian Budnik at UMass Medical School as a research associate, where she assisted in several projects examining synaptic development at the neuromuscular junction in Drosophila. Romina volunteered as a science teacher in India for a few years and later worked as a lab manager in a postharvest lab in Chile. From 2015 to 2017, she studied glia’s role in axon maintenance in the laboratory of Dr. Marc Freeman at UMass Medical School. Romina rejoined the Freeman lab in 2019, after it relocated to the Vollum Institute.

Rachel De La Torre

Rachel De La Torre, B.S.
Graduate Student

Rachel earned a B.S. in Micro/Molecular Biology from Portland State University in 2015. She then spent several years researching immune signaling mechanisms underlying psoriasis and atopic dermatitis in the OHSU Dermatology Research Division. During the summer of 2015, she studied under the mentorship of Dr. Mary Logan in the Jungers Center at OHSU as a Portland State University McNair Scholar investigating glial cell involvement in synaptic loss in the context of Alzheimer's disease. Interested in furthering her neuroscience background, Rachel was accepted to the 2018–2019 cohort of the OHSU/Vollum Institute Neuroscience Post-Baccalaureate Initiative where she studied glial mediated elimination of dying neurons in the Freeman Lab. She continues this work now as an NGP graduate student.

Kevin Guttenplan

Kevin Guttenplan, Ph.D.
Postdoctoral Fellow

Kevin received his B.A. in Neuroscience and Mathematics from Pomona College in 2014, where he used biochemistry to characterize novel proteins in Drosophila melanogaster and mathematical modeling to better understand neuronal development. He then joined the lab of Dr. Ben Barres at Stanford University to study the role of astrocytes in mouse models of central nervous system diseases and injuries, earning his Ph.D. in Neurosciences in 2021. As a postdoc in the Freeman Lab, Kevin now studies the mechanisms that allow astrocytes to sense and respond to changes in the brain, including how astrocytes influence neuronal circuits.

Kona the Freeman Lab service dog

Kona Guttenplan
Official Lab Lab

Kona received her dogtorate at service dog school in 2021 and joined the Freeman Lab soon after. As official Lab lab, Kona focuses on inflammatory responses of the enteric nervous system as well as novel applications of puddle water.

Dongeun Heo head shot

Dongeun Heo, Ph.D.
Postdoctoral Fellow

Dongeun received her B.S. degree in Neurobiology from Georgetown University, where she first developed her interest in glial cells in the lab of Jeffrey Huang. She earned her Ph.D. in Neuroscience from Johns Hopkins University, where she studied oligodendrocyte lineage cells using a diverse set of transgenic mouse lines in the lab of Dwight Bergles. Dongeun joined the Freeman and Monk labs in September 2021 and is interested in investigating the development and function of astrocytes using both fruit fly and zebrafish models.

Madie Hupp

Madie Hupp,
Graduate Student

Madie received her B.S. in Biology at Kennesaw State University, where she researched Akirin’s role in heart development using Drosophila melanogaster in the Nowak lab. After graduation, she joined the Allen Institute for Brain Science in their efforts to describe and map different cell types in the mouse and human brain. Madie also contributed to Alzheimer’s Disease research using spatial transcriptomics. In 2022, she matriculated into the Neuroscience Graduate Program, then joining the Freeman lab in 2023 to follow her interests and study mechanisms underlying synaptic pruning. 

Taylor Jay

Taylor Jay, Ph.D.
Postdoctoral Fellow

Taylor grew up in Kansas and received her B.S. in Brain & Cognitive Science and in Physics from the Massachusetts Institute of Technology. She did her Ph.D. training at Case Western Reserve University, studying microglial function in Alzheimer’s disease and neurodevelopment with Gary Landreth and Bruce Lamb. She began her postdoctoral fellowship in the Freeman lab in 2019, where she is studying the role of glia in synapse development and plasticity.

Amanda Jefferson

Amanda Jefferson, B.S.
Senior Research Assistant

Amanda graduated from Portland State University with a B.S. in Biology in 2016. During her undergraduate studies she assisted in the labs of Philip Copenhaver (Department of Cell, Developmental and Cancer Biology, OHSU) and Mike Forte (Vollum Institute). Upon joining the Freeman lab Amanda has assisted in research examining neuron and glia communication during neuronal remodeling. In addition to her lab responsibilities, she also manages the Vollum Fly Food Core.

Yunsik Kang

Yunsik Kang, Ph.D.
Postdoctoral Fellow

Yunsik received his Ph.D. in Genetics in 2016 from University of Wisconsin-Madison, studying the genetic control of cell death during Drosophila development. He joined the Freeman Lab in 2016, and his research focuses on identifying mechanisms that eliminate unneeded cells in the brain.

Katy Lehmann

Katy Lehmann,
Postdoctoral Fellow

Katy earned a B.S. in Biology and Health, Science, Society and Policy from Brandeis University in 2016. While at Brandeis she worked in Dr. Avi Rodal’s laboratory to investigate how the regulation of endosomal trafficking in Drosophila hemocytes contributes to systemic immune activation. She then spent two years at the NIH as an IRTA Fellow in Leo Belluscio’s lab defining the role of glia in mouse olfactory system development. Katy joined the Freeman lab in 2019 and is interested in the neuron/glia signaling mechanisms underlying synaptic pruning.

Ernesto Manzo

Ernesto Manzo, Ph.D.
Postdoctoral Fellow

Ernesto received his B.A. in Biology from Swarthmore College where he became fascinated by how genetic alterations cause human disease. In 2010, he was an intern at the Clinic for Special Children, where he studied genetic diseases in the Amish and Mennonite Plain populations under Dr. Erik G. Puffenberger. He received his Ph.D. in Molecular and Cellular Biology from the University of Arizona where he studied metabolic defects implicated in amyotrophic lateral sclerosis (ALS) in the laboratory of Dr. Daniela C. Zarnescu. He is currently interested in how cellular mechanisms control neuronal decay. He uses the fruit fly as a model organism to better understand how neurons survive or degenerate in response to genetic insults. Ernesto is a former HHMI predoctoral Gilliam Fellow with an interest in promoting diversity in higher education.

Pau Meraner

Paul Meraner, M.D.
Senior Research Associate

Paul received an M.D. from the Medical University of Vienna in Vienna, Austria, in 1996, where he also trained as a clinical dermatologist, obtaining board certification in 2005. He then decided to pursue science full time. Coming to the U.S. in 2007, he worked on calcium signaling in the lab of Anjana Rao and Patrick Hogan at Harvard Medical School, Boston, MA, and the La Jolla Institute for Allergy and Immunology in La Jolla, CA. Paul then decided to switch gears from protein biochemistry to systems biology and joined the lab of Abraham Brass at UMass Medical School in Worcester, MA, where he performed CRISPR screens to study virus-host interactions and viral entry mechanisms. The broad applicability of CRISPR technology led to a collaboration with the Freeman lab at UMass, and ultimately to an offer to move out West and join the lab at OHSU. Paul, who always dreamt of working in neuroscience, is currently employing CRISPR screening technology to dissect the SARM1-mediated axon degeneration pathway. Taking advantage of his expertise in biochemisty, he also tries to understand SARM1 signaling at the molecular level.

Mariel Kristine Micael

Mariel Kristine B. Micael,
Graduate Student

Mariel is a PREP scholar in the Freeman lab. She received her B.S in Cognitive & Behavioral Neuroscience from the University of California, San Diego in 2023. While at UCSD, she was an undergraduate research assistant in Nicola Allen's lab where she studied the role of astrocyte-secreted proteins in Alzheimer's Disease and Down Syndrome. Mariel joined the Freeman lab in August 2023 and is currently studying glial mechanisms of synapse elimination in the developing Drosophila. 

Erin Santos

Erin Santos
Graduate Student

Erin earned her B.A. from Colgate University in 2020 where she majored in Neuroscience. During her time at Colgate, she conducted research in Dr. Jun Yoshino's lab, investigating astrocytic modulation of the microglial inflammatory response. Erin joined the lab of Dr. Douglas Fields at the National Institute of Child Health and Human Development (NICHD) as an IRTA fellow in 2020, where she studied activity-dependent changes in myelin and nodes of Ranvier in the mouse visual system. She joined the OHSU Neuroscience Graduate Program in 2022 and became a member of the Freeman Lab in 2023. Erin's research interests now include astrocyte calcium signaling and glial regulation of neuronal circuitry.

Amy Sheehan

Amy Sheehan, B.S.
Senior Research Project Manager

Amy received her B.S. in Biology from Eastern Connecticut State University in 1994. From 1994 to 1999, she was the head research assistant — under the direction of Dr. Petra Ross-Macdonald — on a yeast function genome project in the laboratory of Dr. M. Snyder at Yale University. Amy moved to Eugene, Oregon in 1999. In 2000, she became a research technician III with the Howard Hughes Medical Institute, serving as the head molecular biologist on numerous projects in Dr. Chris Doe's lab at the University of Oregon. From 2004 to 2017, Amy was a research associate II and lab manager in the Freeman lab at the University of Massachusetts Medical School, Worcester, Massachusetts. She continues in her role as the Freeman lab manager here at the Vollum Institute. However, Amy's main job is being the mother of four wonderful kids and running the Freeman household — all with a large glass of wine!

Tobias Stork

Tobias Stork, Ph.D.
Research Assistant Professor

Tobias worked on various aspects of glial development and function using Drosophila as a model organism throughout his career. He earned his masters degree and Ph.D. in Biology in the lab of Christian Klämbt at the University of Münster, Germany — analyzing the genetic control of midline glia development and the anatomy and function of the glial blood-brain barrier. In 2007 Tobias joined the Freeman lab to study the genetic control of astrocyte morphogenesis as well as astrocyte function in the Drosophila nervous system.