People

  • faculty

  • James Knierim

    James Knierim

    Professor of Neuroscience

    Office: 410-516-5170 | Lab: 410-516-5292
    jknierim@jhu.edu
    337 Krieger Hall

    Research Interests: Behavioral Neurophysiology of the Hippocampal Formation

  • assistant research scientists

  • Francesco Savelli

    fsavelli.research@gmail.com

    Research Interests: Your inner sense of location relative to the external world is a cognitive abstraction of your sensorimotor experience -- something that your brain has to "make up." I study the neural circuits responsible for this process. I combine electrophysiology in behaving animals and computer modeling to investigate the functional properties of the spatial cells of the hippocampal formation, such as place, grid, and boundary cells.

  • postdoctoral fellows

  • Xiaojing Chen

    xchen95@jhu.edu

  • Heekyung Lee

    Heekyung Lee

    Heekyung@jhu.edu

  • Manu Madhav

    manusmad@jhu.edu

    Research Interests: Manu is a 5th year postdoctoral research fellow. His research interests involve utilizing tools from robotics, control theory and closed-loop experimental approaches to probe and model neural and behavioral circuits in intact, behaving organisms. In the Knierim lab, he is currently working on the dome project that uses an augmented reality apparatus to tease apart the contribution of landmarks and path integrative cues towards forming the hippocampal cognitive map. http://www.manusmad.com

  • graduate students

  • Doug Goodsmith

    Dgoodsm1@jhu.edu

    Research Interests: The dentate gyrus is thought to be essential for pattern separation, a process necessary for preventing interference between similar memories or experiences. Unlike other hippocampal subfields, the dentate gyrus contains multiple excitatory cell types: granule cells in the granule cell layer and a small number of highly active mossy cells in the hilus. Within the granule cell layer, both mature granule cells and immature adult-born granule cells are present. Due to the close proximity of these distinct dentate gyrus cell types, it has been difficult to differentiate between the activity of dentate cell types using extracellular recordings. Therefore, little is known about the firing properties of cells in the dentate gyrus relative to CA1 or CA3. I am studying the firing properties of mossy cells, mature granule cells, and optogenetically identified adult-born granule cells. By comparing the activity of all excitatory cell types within the dentate gyrus circuit, we hope to determine how each cell type contributes to pattern separation and other dentate functions.

  • William Hockeimer

    whockei1@jhmi.edu

  • Vyash Puliyadi

    Vyash Puliyadi

    vyash.puliyadi@jhu.edu

  • Chia-Hsuan Wang

    Chia-Hsuan Wang

    PhD Candidate, Dept. of Neuroscience, Mind/Brain Institute, Johns Hopkins University

    chwang@jhu.edu

  • undergraduate students

  • lab staff

  • Marissa Ferreyros

    mferrey1@jhu.edu

  • Geeta Rao

    Geeta Rao

    Lab Manager

    geetarao@mail.mb.jhu.edu

    Research Interests: Intermittent locomotion, exploration consisting of alternating bouts of forward progression and pauses, is a ubiquitously observed behavior. During the pauses in locomotion, rats engage in scanning behavior, consisting of lateral or vertical head movements, presumably to investigate environmental features. We have previously shown that increased neural activity during head scanning predicted the formation and potentiation of place fields on the next pass through that location (Monaco et. al, 2014.) This phenomenon may reflect single-trial encoding of non-spatial information onto a spatial framework, a hallmark of episodic memory. We plan to further characterize scan-related hippocampal place cell firing and field potentiation in hippocampal CA1 and CA3 subfields. We are also currently examining whether changes in scanning behavior and scan-related hippocampal cell firing may contribute to cognitive spatial deficits observed in old animals. Whether scan potentiation of place fields in old animals occurs is a particularly intriguing question that we will be addressing in the near future with further data acquisition. Whether firing during scanning behavior signals particularly salient locations in the environment, such as reward encounters, is a further avenue of investigation.

  • Arjuna Tillekeratne

    Research Technologist

    arjunatill@jhu.edu

  • collaborators

  • Kim Christian

    Kim Christian

    Research Assistant Professor of Neuroscience, Perelman School of Medicine, University of Pennsylvania

    kchristi@pennmedicine.upenn.edu

  • Noah Cowan

    Associate Professor, Department of Mechanical Engineering, Johns Hopkins University

  • Kathleen Cullen

    Professor, Department of Biomedical Engineering, Whiting School of Engineering

  • Katie Hedrick

    Assistant Professor, Dedman College of Humanities & Sciences, Southern Methodist University

  • Ravikrishnan Jayakumar

    rperurj1@jhu.edu

    Research Interests: Ravi Jayakumar is a Ph.D candidate in Prof. Noah Cowan's LIMBS Lab at JHU. His current research focus is on the role that path integration plays in the formation and update of the internal cognitive map. Ravi and Manu Madhav, a post doc from Prof. James Knierim's lab, have been the primary drivers in the design & construction of the Dome, a novel augmented reality experiment apparatus designed at teasing apart this question. Previous work from this project has revealed that the path integrator gain, as revealed by CA1 place cell activity, is highly plastic and is recalibrated by the animal's recent experience with external landmarks and their relationship to the animal's self-motion cues.

  • Sang Hoon Kim

    skim219@jhmi.edu

  • Hongjun Song

    Professor, Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania

  • Kechen Zhang

    Associate Professor of Biomedical Engineering and Neuroscience, Johns Hopkins University School of Medicine

  • former lab members

  • Sachin Deshmukh

    Assistant Professor, Center for Neuroscience, Indian Institute of Science, Bangalore, India

  • Yoganarasimha Doreswamy

    Associate Professor, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka

  • Eric Hargreaves

    Deep Brain Stimulation Clinical Neurologist, Deep Brain Stimulation Program, Robert Wood Johnson University Hospital

  • Jeremy Johnson

    Medical Student, Emory University

  • Inah Lee

    Associate Professor, Laboratory for Behavioral Neurophysiology of Learning and Memory, Seoul National University

  • Nick Lukish

    Research Technologist

  • Joshua Neunuebel

    Assistant Professor, Department of Psychological and Brain Sciences, University of Delaware

  • Eric Roth

    Assistant Professor, Department of Psychology and Brain Sciences, University of Delaware

  • Jennifer Siegel

    Postdoctoral Associate, Center for Learning and Memory, University of Texas-Austin

  • Horatiu Voicu

    Scientific Programmer, Genomics and Proteomics Core Laboratory, Baylor College of Medicine

  • Xintian Yu

    Scientific Programmer, Dept. of Neonatology, University of Texas-Houston

  • undergraduate