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Sweeney Group

Evolution, Development, and Function of Motor Circuits

Movement is fundamental to nearly every animal behavior: to escape predators, to eat and breathe, animals must move. The Sweeney Group aims to define the molecular, cellular and neural circuit components that underlie differences in motor behavior, and to explore how such differences arise during an organism’s development.

The group uses the Xenopus frog to address these fundamental questions. The frog undergoes metamorphosis, transitioning from a swimming tadpole to a walking frog during development. The Sweeney Group exploits this transition and categorizes, compares and manipulates frog neurons at each stage. This allows the scientists to map variations in cellular properties and neural circuit structure onto differences in motor behavior.

Knowledge about such cell-circuit-behavior relationships in the frog will provide a basis for comparing motor circuits between tetrapods, understanding how motor circuits evolved from swimming to walking during evolution, and pinpointing how motor circuits break down in movement disorders.


Image of Sophie Gobeil

Sophie Gobeil

PhD Student

Image of Iurii Ignatev

Iurii Ignatev

PhD Student

Image of Georgiy Ivanian

Georgiy Ivanian

Scientific Intern

Image of Vera Magalhaes de Sousa Figueiredo

Vera Magalhaes de Sousa Figueiredo

Research Technician

Image of Stavros Papadopoulos

Stavros Papadopoulos

PhD Student

Image of Matthijs Smits

Matthijs Smits

Research Technician

Image of Florina-Alexandra Toma

Florina-Alexandra Toma

PhD Student

Image of David Vijatovic

David Vijatovic

PhD Student

Image of Alexia Wilson

Alexia Wilson

PhD Student

Current Projects

Single cell sequencing of tadpole versus frog neurons | Viral tracing of neural circuits for swimming and walking | Multiphoton imaging of calcium dynamics over metamorphosis


Godavarthi SK, Hiramoto M, Ignatyev Y, Levin JB, Li HQ, Pratelli M, Borchardt J, Czajkowski C, Borodinsky LN, Sweeney LB, Cline HT, Spitzer NC. 2024. Postsynaptic receptors regulate presynaptic transmitter stability through transsynaptic bridges. PNAS. 121(15), e2318041121. View

Wilson AC, Sweeney LB. 2023. Spinal cords: Symphonies of interneurons across species. Frontiers in Neural Circuits. 17, 1146449. View

Salamatina A, Yang JH, Brenner-Morton S, Bikoff JB, Fang L, Kintner CR, Jessell TM, Sweeney LB. 2020. Differential loss of spinal interneurons in a mouse model of ALS. Neuroscience. 450, 81–95. View

View All Publications

ReX-Link: Lora Sweeney

Open Positions

The Sweeney Group is looking for accomplished students and postdocs with experience in molecular/genetic, computational, anatomical and functional dissection of neural circuits and interest in motor circuits, frog metamorphosis, comparative studies between frog and mouse or motor circuit evolution. If interested, please email with your CV, motivation letter and contact details of 2-3 referees.


Since 2020, Assistant Professor, Institute of Science and Technology Austria (ISTA)
2011-2020 Postdoc, Salk Institute for Biological Studies, USA
2011 PhD, Stanford University, USA

Selected Distinctions

2019 Helmholtz Young Investigator Award, MDC Berlin and Helmholtz Foundation (declined)
2012 Damon Runyon HHMI Fellow
2012 Finalist, Larry Sandler Memorial Award
2011 Salk Pioneer Fund Post-doctoral Scholar Award
2009 Lieberman Fellowship, Stanford University

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