Dr. Nikolas Karalis

Nikolas is a tenured researcher (chargé de recherche) at the French National Institute of Health and Medical Research (INSERM) and team leader at the Paris Brain Institute (Institut du Cerveau - ICM), where he leads the Neuronal Circuits & Brain Dynamics team, supported by the European Research Council (ERC) Starting Grant.

Nikolas studied Applied Mathematics and Physics at the National Technical University of Athens. 

He has always been fascinated by the complexity of the brain, so he decided to shift his focus to Neuroscience, and joined the Neurasmus Master’s program in Neuroscience in Berlin and Bordeaux, where he worked with Cyril Herry on the neuronal circuits of fear behavior. 

During his Ph.D., he worked with Anton Sirota at the Ludwig Maximilian University of Munich, where he investigated the role of breathing in entraining neuronal dynamics and engaged in the large-scale characterization of the oscillatory architecture of memory circuits. 

As an EMBO & MSCA postdoctoral fellow in the group of Andreas Lüthi at the Friedrich Miescher Institute for Biomedical Research (FMI) in Basel, and later as SNF Ambizione team leader at the FMI, he used a combination of modern neurotechnologies to unravel the role of neuromodulators in coordinating the activity of the amygdala during behavior.

In 2024, Nikolas joined the French National Institute of Health and Medical Research and the Paris Brain Institute, with the support of the ATIP-Avenir, Ambizione, and ERC Starting grants.

Dr. Irene Serra Hueto

Irene studied Biotechnology at the University of Zaragoza. Her curiosity about how the brain processes information led her to pursue a Master's degree in Neuroscience at the Autonomous University of Madrid, where she became fascinated by the dialogue between neurons and astrocytes as a fundamental component of the modulation of plasticity in the brain.

Following this scientific interest, during her Master’s thesis she started working on astrocyte-neuron interactions with Gertrudis Perea at the Cajal Institute, CSIC. 

For her Ph.D. she joined the emerging laboratory of Marta Navarrete, where she developed a project based on the implementation of novel molecular tools aimed at dissecting astrocytic functional heterogeneity in mice circuits of the nucleus accumbens. 

Her research demonstrated the existence of functionally specific astrocyte subsets, defined as astrocytic ensembles, associated with behavior. During this period, Irene completed an EMBO-funded internship with Prof. George Malliaras at the University of Cambridge and joined the Young Researchers Committee of the Spanish Society of Neuroscience (SENC) as an active organizer of the SENC mentoring programme.

She joined our team in 2025, and she is currently working on a project trying to understand the role of cell-type specific neuromodulation in the context of cognitive flexibility with the support of the FRM postdoctoral fellowship and EMBO LTF postdoctoral fellowship.

Dr. Javier Alegre-Cortés

Javier studied Biochemistry and Biomedical Sciences at the University of Valencia. Following an interest on understanding how circuits emerge from the orchestrated activity of neurons, he earned a Master’s degree in Neuroscience at the Universidad Miguel Hernández de Elche, researching texture discrimination under the supervision of Miguel Maravall.

He obtained his PhD at the Bioengineering Institute of Elche, in the Visual Neuroprosthetics lab led by Eduardo Fernández. Here, he recorded populations of neurons of rats’ visual cortex and explored the temporal structure of their activity in the context of interval timing.

He then joined the group of Ramón Reig at the Instituto de Neurociencias, where he was lately awarded a Margarita Salas fellowship. He investigated the slow wave activity to understand the communication of cortical and striatal circuits, using a combination of data science and computational modelling techniques.

In 2025, he joined the Neuronal Circuits & Brain Dynamics team led by Nikolas Karalis at the Paris Brain Institute.

Kaleab Belay

Kaleab did his bachelor’s degree in Software Engineering in Addis Ababa Insititute of Technology and studied Machine Learning for his master’s degree in MBZUAI, Abu Dhabi, UAE. 

His primary interest is in applying insights from Neuroscience to build machine learning models capable of learning continuously. 

He wrote his master’s thesis on how robots can perform Simultaneous Localization and Mapping with approaches inspired by the neuronal mechanisms of the hippocampal formation in mammals. 

Following the completion of his studies, Kaleab joined our lab in September 2024, where he is currently using artificial neural networks to model the effects of neuromodulators in the brain.

Yuki Nomura

Yuki studied Science and Medical technology at the Azabu University in Japan. 

After gaining experience in the clinical field, she moved to neuroscience to study the development of the cerebral cortex at the Kazunori Nakajima lab at Keio University, where she learned in vivo genetic manipulation techniques. 

She then joined the lab of Victor Borrell at Instituto de Neurociencias in Spain, expanding her expertise on developmental neuroscience and being involved in neuroimaging for MRI data. Later, at Felix Leroy's lab, she contributed to behavioral experiments and analysis using machine learning. 

She is now a lab technician in our lab, where she is responsible for the lab organization and she is contributing to our ongoing projects and experiments.

Lahna Bekri

Lahna studied applied mathematics and engineering at École Polytechnique, where she became increasingly interested in how complex brain dynamics emerge from biophysical principles. She developed a strong taste for linking mathematical models with neural mechanisms, particularly through dynamical systems and theoretical neuroscience.

In 2026, she joined the Neuronal Circuits & Brain Dynamics team led by Nikolas Karalis at the Paris Brain Institute as part of her Master’s thesis. Her current work focuses on biophysical modeling of neural circuits and the study of how different neuromodulatory conditions shape large-scale dynamical regimes in the brain.

Harys Saidi

Justine Leparmentier

Justine is currently studying neuroscience and data science at the University of California, Berkeley. 

Her undergraduate research has focused on optogenetically induced signaling pathways mediating self-organization in human neural tube stem cell models. This has driven her interest in how early developmental processes shape neural circuit formation and behavioral outcomes. 

Drawing on her background in bioengineering, she is interested in expanding into computational neuroscience, exploring the gap between cellular mechanisms and systems-level behavior.

Nesara Shree

Mazarine Chambon

Mazarine is a third-year Bachelor student in Life Sciences Engineering at EPFL. Her academic background combines training in quantitative sciences, including mathematics and programming, with a strong foundation in biology. During her studies, she developed a particular interest in neuroscience and computational approaches to understanding brain function. She will join the Neuro-X Master’s program at EPFL next year to further pursue these interests.

This summer, she will join the Neuronal Circuits and Brain Dynamics team as an intern, where she is eager to gain hands-on research experience.