Mentis Lab
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George Z. Mentis, Ph.D.
Principal Investigator
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Professor in Pathology and Cell Biology (in Neurology)

Member Faculty of Motor Neuron Center at Columbia University




Post-doctoral Research Scientists

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  Nicolas Delestree, Ph.D.
  Associate Research Scientist
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      Nicolas completed his Ph.D. in Neuroscience from Pierre and Marie Curie University in Paris, France in June 2015, working on the cellular mechanisms involved in the pathogenesis of amyotrophic lateral sclerosis (ALS) in mouse models of disease. He joined the Mentis Lab in July 2015 and his current studies involve studies of synaptic dysfunction from descending pathways to the spinal cord (with emphasis on serotonergic transmission) in mouse models of spinal muscular atrophy (SMA). Nicolas is a Fellow from the Association Francaise contre les Myopathies (AFM). 
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 Danny M. Florez-Paz, Ph.D.
 Associate Research Scientist
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       Danny completed his Ph.D. in Neuroscience from Neuroscience Institute of Alicante, Spain in June 2016, studying the electrical and mechanical properties of proprioceptive neurons in mice. He completed a 2 year postdoctoral study with Ellen Lumpkin at Columbia University studying the role of extracellular matrix in mechanical transduction in cutaneous touch receptors. He joined the Mentis Lab in March 2019 and his current studies involve studies of sensory-motor refinement mediated by the classical complement pathway during normal development, as well as synaptic dysfunction of proprioceptive synapses in mouse models of spinal muscular atrophy. 
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Jahnavi Simhadri, Ph.D.
Post-doctoral Research Scientist
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       Jahnavi completed her Ph.D. in Pharmacology from Northeastern University,  in Boston, USA, Germany in May 2025, studying GIRK channels to better understand common and rare epilepsies under the mentoring of Dr Diomedes Logothetis. She also holds a Masters degree (Aug2022) studying the site of action of urea based activators of GIRK channels. She joined the Mentis Lab in November 2025 and her current studies focus on the characterization of the intrinsic properties of ventral spino-cerebellar tract neurons during early development. In addition, she will identify synaptic targets from VSCT neurons to other spinal interneurons.
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Jiaxing Wang, Ph.D.
Post-doctoral Research Scientist
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       Jiaxing completed his Ph.D. in Pharmaceutical Sciences from the Univ of Tennessee Health Science Center in August 2024, screening and evaluating small molecule compounds and utilizing the most promising candidate as a tool molecule for target validation of TRPC3 in Alzheimer's disease models. He joined the Mentis Lab in September 2024 and his current studies focus on understanding the cellular and neuronal circuit mechanisms involved in the neurodegeneration in mouse models of amyotrophic lateral sclerosis (ALS) by using morphological assays as well as electrophysiological techniques including EMG and tension recordings from adult mouse models of ALS.
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  John G. Pagiazitis, Ph.D.
 Post-doctoral Research Scientist
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       John was awarded a PhD in Neurological Sciences from Aristotle University of Thessaloniki, Greece, although he performed his entire PhD studies in the Mentis Lab at Columbia University. His studies are focused on the influence of descending pathways on motor neuron output during early postnatal development and its potential changes during the course of the neurodegenerative disease spinal muscular atrophy. He has focused his investigations on the catecholaminergic synapses on spinal neurons, including motor neurons, using SMA mouse models and how their dysfunction is affecting locomotor behavior under neurodegenerative diseases.

Graduate & Undergraduate students

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Paul Holzer
 Medical Student, Ruhr-University, Bochum, Germany
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       Paul is a medical student from Ruhr University, Germany and has joined the Mentis Lab as an ICEP student for one year. He joined the Mentis Lab in Sept 2025. Paul is interested in studying the anatomical features of ventral spinocerebellar tract (VSCT) neurons with particularly emphasis on their connectivity via their axon collaterals. In addition, he will be studying how VSCT neurons respond to various pathological conditions such spinal cord injury, ALS, SMA and other movement disorders. Paul is working closely with Dr Nicolas Delestree in the Mentis Lab.

Technical team


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Antigoni Lekka
Lab Manager

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Antigoni joined the Mentis Lab in September 2024. She holds a Masters degree in Applied Biology and Biotechnology from University of Athens, Greece. Her main responsibilities include maintenance of the mouse colonies, genotyping and different biochemical assays used in the Lab. She is also involved in some of the immunohistochemical assays coupled with confocal microscopy in different projects in the lab.

Lab Alumni


Estelle Drobac, PhD, Medical doctor, Paris, France
Emily Fletcher, PhD, Group Leader, Perth Children Hospital, Australia
Christian Simon, PhD, Group Leader, University of Leipzig, Germany
Sara Ebrahimi Nasrabady, MD. PhD, Research Fellow in Psychiatry, Columbia University
Nandhini Sivakumar, PhD, Adjunct Assistant Professor, Michigan
Anna Janas, MD. PhD, Pediatric Neurology, Stanford University
Joshua Chalif, MD. PhD, Resident in Neurosurgery, Harvard University
Aleksandra Vukojicic, PhD, Postdoctoral Fellow at Eli Lilly
JoonHyung Park, PhD, Postdoctoral Fellow at Penn


Mentis lab photo Dec 2025

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Mentis lab photo Jan 2025
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Mentis lab photo Dec 2023
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Mentis lab photo June 2023
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Mentis lab photo March 2021

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Mentis Lab photo Aug 2019
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Mentis Lab photo Dec 2016
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Mentis Lab photo Feb 2014
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Laboratory of George Z. Mentis, PhD          Center for Motor Neuron Biology and Disease         Departments of Pathology & Cell Biology  and Neurology       Columbia University