Rajyashree Sen

About Me

Hello!

My name is Rajyashree, a.k.a. Rai (pronounced 'rye', like the bread).

I am a postdoctoral research scientist in the lab of Nobel Laureate Dr. Richard Axel at Columbia University. I also collaborate with theorists Dr. Stefano Fusi and Dr. Larry Abbott. I study cognitive maps—internal representations of relational structure in the world. My current research explores how the frontal cortex represents relational structure in physical space, allowing animals to extrapolate from explored to unexplored regions of the environment (for example, when taking shortcuts or planning routes through previously unvisited regions). Extending this framework to the domain of social cognition, I also examine how neural circuits represent individual identity alongside relational structure in social hierarchies, and how animals generalize and predict the behavior of unfamiliar individuals based on prior experience with similar ones. In the long run, I am interested in how animals flexibly switch between discrimination and generalization to guide adaptive behavior.

I was born and raised in India. I completed my Bachelor's in Microbiology at St. Xavier's College Kolkata, and my Master's in Biotechnology at the University of Hyderabad. I earned my PhD in the lab of Dr. Barry Dickson , initially at the Research Institute of Molecular Pathology in Austria and later at Janelia Research Campus in the US, when the Dickson lab relocated. As a graduate student, I dissected the neuronal pathways for evasive (backward) walking in fruit flies.

In parallel to my scientific work, I love teaching and bringing scientists and general audiences into conversation. I teach a semester-long course on the social brain to incarcerated individuals through Columbia University’s Prison Education Project. In 2024, I founded The Lab, an improvisational comedy show inspired by interviews with scientists that uses comedy to makes neuroscience accessible to broad audiences.

Curriculum Vitae: Download PDF

Research

Postdoctoral Work

Direction 1 - Neural basis of individual recognition

The brain appears to maintain a repository of the individuals we know. This cognitive archive is believed to interface with other brain regions to ascribe significance to each individual. The intricacy of this system is underscored by the highly personal and variable meanings we attach to different individuals. I am interested in fundamental questions about this process: where in the brain is this repository of social representations? How is meaning imposed on representations of individuals, such that one knows the nature of the relationship with an individual they have encountered? How is this repository affected by disease? In part of my postdoctoral work, I use mouse as a model system to address these questions. I record neural activity in the frontal cortex—a brain region implicated in social cognition—while mice interact with conspecifics, to determine whether representations of individual identity can be identified in the cortex during social interactions, whether these representations persist as memory, and whether they serve as a substrate for the imposition of meaning or value on an individual. This research is partly supported by a Brain and Behavior Research Foundation Young Investigator Grant.

Direction 2 - Neural basis of abstraction and cogntive maps

At the Zuckerman Institute, where I work, the building has a regular structure: every even-numbered floor shares a common layout, distinct from the odd floors. On a less familiar even floor, I can still orient myself—finding the meeting rooms, kitchen, or the restroom by generalizing from previous experience. Yet my own lab on the eighth floor carries a different kind of significance. The bench where I conduct experiments is tied to specific memories, and an identical space elsewhere, though easy to navigate, does not evoke the same associations. This points to the brain's ability to both encode specific experiences and abstract the relational structure of the environment, supporting generalization across contexts. A part of my postdoctoral research investigates how the brain builds representations of relational structure that enable generalization beyond direct experience. In my postdoctoral work, I identified a novel spatial code in the frontal cortex that supports extrapolation. This representation allows the brain to infer position in parts of the environment it has not directly experienced—for example, enabling animals to take shortcuts through unfamiliar routes. This work now opens the opportunity to study a new class of spatial representation and what it enables. More broadly, it provides a framework for understanding how the brain organizes information into relational structures, abstracts their underlying regularities, and uses them to draw inferences. I am now extending this line of research beyond space to domains such as social cognition, where individuals must be distinguished while also interpreted within a broader relational structure—such as social hierachies. I am particularly interested in whether cortical circuits can infer the status of unfamiliar individuals based on prior experience with similar ones.

Animals can act on specific representations or generalized knowledge of relational structure, depending on context and internal state. In the long run, I aim to understand how internal state and context enable flexible switching between these modes to guide adaptive behavior.

Graduate Work

My earlier work focused on the neuronal basis of sensorimotor transformations using the fruit fly as a model system. Flies, when confronted with a physical barrier or a visual threat, sometimes make a hasty retreat by walking a few steps backwards and turning away. During my PhD, I dissected the neuronal pathways for this backward walking retreat. My work focused on a set of neurons—dubbed the Moonwalker Descending Neurons (MDNs)—which when activated trigger flies to walk backwards. I generated genetic tools that enabled me to access small neuronal populations in the fly nervous system and manipulate them. Using calcium imaging and optogenetics to monitor and manipulate neural circuits, I showed that the MDNs receive aversive visual and mechanosensory inputs to trigger retreat in aversive environments. I also characterized critical interneurons within the fly ventral nerve cord downstream of the MDNs, essential for the execution of backward walking. Altogether, my graduate research delineates a comprehensive neural circuit, demonstrating how sensory information from different modalities leads to the activation of a ‘command-like’ neuron, and how this neuron's activity translates into a coordinated motor response.

Publications

1. Rajyashree Sen, Alexander Medoff, Lorenzo Posani, Larry Abbott, Richard Axel, Stefano Fusi (2026). “The medial frontal cortex abstracts space onto a flat manifold”. In Preparation.
2. Rajyashree Sen, Alexander Medoff, Molly Rose Graff, Baihe Zhang, Mira Vanchiswar, Larry Abbott, Richard Axel (2026). “Combined coding of social and spatial information in the mouse dorso-medial prefrontal cortex” In Preparation.
3. Valentine Andreu, Rajyashree Sen, Nour El Houda Mimouni, Eun Ji Lee, Dianne-Lee Ferguson, Alexis Stutzman, Bianca J. Marlin (2025). “Early postpartum development of pup urine preference in mothers” bioRxiv. DOI: 10.1038/s41467-020-19936-x
4. Kai Feng, Rajyashree Sen, Ryo Minegishi, Michael Dübbert, Till Bockemühl, Ansgar Büschges, Barry J Dickson (2020). “Distributed control of motor circuits for backward walking in Drosophila” Nature Communications. DOI: 10.1038/s41467-020-19936-x
5. Rajyashree Sen, Kaiyu Wang, Barry J. Dickson (2019). “Twolumps ascending neurons mediate touch-evoked reversal of walking direction in Drosophila” Current Biology 29(24): 4337-4344.e5. DOI: 10.1016/j.cub.2019.11.004
6. Rajyashree Sen, Ming Wu, Kristin Branson, Alice Robie, Gerald M. Rubin, Barry J. Dickson (2017). “Moonwalker descending neurons mediate visually evoked retreat in Drosophila” Current Biology 27(5): 766-771. DOI: 10.1016/j.cub.2017.02.008

Teaching

Guest Lecturer: The Parental Brain Seminar at Columbia University - Fall 2023, 2024

I was invited by Dr. Bianca Jones Marlin to serve as a guest lecturer for 'The Parental Brain' seminar at Columbia University. In this role, I developed a module for the syllabus and facilitated discussions on scientific papers that explore various aspects of the parental brain. In my classes, the students collectively examined five crucial questions for each paper: What is the central problem? What methods were used? What arguments are presented? What are the conclusions? What are the broader implications? We focused extensively on the implications to understand how each experiment contributed to and influenced the broader scientific context. My decision to 'invert the classroom' and emphasize student leadership was driven by the principle that education is not merely about 'telling' and being 'told,' but is instead an active and constructive process.

Lecturer: Columbia University's Prison Education Project - Fall 2024

The Parental Brain at Taconic Women's Prison

Building on the work I initiated in the 'The Parental Brain' seminar at Columbia University, I extended this curriculum to the Taconic Correctional Facility in Fall 2024, as part of Columbia University’s Prison Education Project. This semester-long course was carefully adapted to meet the unique needs of a technology-free environment at a medium-security women’s prison. Notably, the coursework provided through this program contributes to an associate degree that the inmates are pursuing through Hudson Link, with Columbia credits counting towards their degree completion. Working alongside Dr. Bianca Jones Marlin and Dr. Thiago Arzua , we tailored both the syllabus and teaching methods, and orchestrated a collaborative student project that bridged the academic gap between the Taconic students and their Columbia peers. For this project, the Taconic students proposed an original research idea, while the Columbia students were tasked with reviewing primary literature and creating accessible science presentations based on that idea. This collaboration equipped the Columbia students with real-time feedback on their science communication skills and literature review techniques, and helped the Taconic students refine their research proposals and presentation skills. The exchange proved highly beneficial, enhancing the learning experience for all involved by fostering a dynamic and reciprocal educational dialogue.

Improv Comedy

Lessons From Stage to Science

I've been involved in improv comedy for as long as I've been involved in research, having begun during my first year of my PhD in Vienna, Austria. Since then, I've continued to do improv in every city where I've lived. Improv comedy has given me skills that make science communication entertaining, accessible and clear, whether I'm teaching a class, responding to questions at conferences, or explaining science to the general public. Keeping your eyes and ears open is vital to being a good improviser—it allows one to catch the unexpected events and weave them into the narrative. Those lessons have also proved useful for my science; the ability to see and explore the unexpected has often led me to important insights and interesting places.

My training spans over a decade across historic comedy institutions that have shaped some of the most influential comedic voices of our time, including the Second City Conservatory, Upright Citizens Brigade, iO Chicago, Washington Improv Theater, and Magnet Theater. Over the years, I've performed for large audiences as part of several improv teams and festivals, including house teams at Washington Improv Theater , Laugh Index Theater (DC), and Magnet Theater (New York). Currently, I produce 'The Lab,' an indie improv show inspired by scientist interviews.

The Lab: Bridging Community and Science Through Improv Comedy

A Public Engagement Project

'The Lab' is a monthly improv-comedy show offering science-inspired performances. Each show is driven by an interview with a neuroscientist, whose life and work inspire the show. I founded the group with funding from Columbia University's Public Engagement Program in 2024, and further expanded it with a Civic Engagement Microgrant from Research! America and an Annual Artists Grant from The Puffin Foudation in 2025-2026. The show was developed in partnership with the artistic community at Magnet Theater in New York City, where I perform weekly. The mission of this project is to make neuroscience accessible and engaging through improvisational comedy. Our objectives include humanizing scientists, demystifying neuroscience, and providing practical advice for young people interested in research, particularly those who don't see themselves reflected in scientific careers.

Go to The Lab's Official Website

Contact

Email

rs3966@columbia.edu

Address

Axel Lab
Zuckerman Institute
Columbia University
3227 Broadway, New York
NY 10027

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