People

  • faculty

  • 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

  • Heekyung Lee

    Heekyung Lee

    • Heekyung@jhu.edu
    • Research Interests: The hippocampus plays an important role in memory formation, storage, and retrieval. In particular, the CA3 subregion of the hippocampus has received attention for its potential role in associative memory because of its strong recurrent circuitry. Using electrophysiological approaches, my current research is focused on understanding the neural computation in the CA3 subregion, in both young and aged animals.
  • Manu Madhav

    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
  • postdoctoral fellows

  • Teruko Danjo

    Teruko Danjo

    • teruko@jhu.edu
    • Research Interests: Roles of interregional communications within the hippocampal network
  • Yueqing Zhou

    Yueqing Zhou

    • zhouyq@jhu.edu
    • Research Interests: Exploratory-related head-scanning predicts the generation of new place fields or the potentiation of existing place fields in hippocampus. Combing MFB stimulation and in-vivo one-photon calcium imaging techniques, my project focus on understanding how reward contributes to the head-scanning behavior and formation or potentiation of place fields in rats. Ring attractors are a class mechanistic model of internal dynamics underlying the head-direction (HD) system. By recording retrosplenial cortex in Dome which developed by Knierim Lab, my work also focus on providing evidence to understand whether the ring attractor models are compatible with brain anatomy and physiology in the ability of these allothetic inputs to control the activity hill in cases where the animal is disoriented or when there is a conflict between different sources of allothetic directional information.
  • graduate students

  • Yuxi Chen

    Yuxi Chen

    • ychen315@jhmi.edu
    • Research Interests: Yuxi Chen is a first-year neuroscience PhD student. She worked on the neural basis of sensorimotor sequence generation as an undergrad and now looks forward to a hippocampal adventure in the Knierim lab.
  • William Hockeimer

    William Hockeimer

    • whockei1@jhmi.edu
    • Research Interests: Electrophysiological data from the hippocampus has revealed that individual neurons called place cells are active in certain spatial locations and that this activity can be modulated by the the non-spatial, sensory cues present. This has led to a theory called the Cognitive Map Theory which proposes that memories about our experiences are encoded in terms of the locations in which they took place. My project seeks to provide a direct test of an idea regarding how the Cognitive Map could be constructed at the neural level. A hypothesis termed the
  • Bharath Krishnan

    Bharath Krishnan

    • bharath@jhmi.edu
    • Research Interests: The medial Entorhinal Cortex (MEC) is a region in the temporal lobe of the brain that is perhaps most well-known as the place where grid cells were first discovered. Apart from being home to grid cells, this region contains a plethora of other cell types with very interesting properties such as border cells, speed cells, object-vector cells etc. As one the primary inputs to the hippocampus, the MEC is thought to provide an allocentric representation of space and comprise the neural substrate for path-integration. The goal of my project is to understand the specific computations performed in the MEC with the help of electrophysiological recordings performed in the Dome apparatus. Learning more about how MEC cells respond to 'recalibration' of the path integrator could shed more light on how this vital region contributes to the formation of our perception of the world around us.
  • Leo Lee

    Leo Lee

    Master's Student

    • jlee552@jhu.edu
    • Research Interests: Uncover the mechanism behind scan-potentiated hippocampal place fields while also developing an optical imaging technique for measuring neuronal activity in freely moving rats. Additionally, it would be interesting to see how analyzing sensory information such as visual input can influence memory formation and consolidation in the hippocampus.
  • Vyash Puliyadi

    Vyash Puliyadi

    • vyash.puliyadi@jhu.edu
    • Research Interests: The lateral entorhinal cortex is one of the major inputs into the hippocampus and appears to particularly vulnerable in both aging and Alzheimer’s disease. In Alzheimer’s disease, there is significant neuronal loss and synaptic loss observed, early in disease progression. Similar findings have been observed in naturally aged Long Evans rat model of aging. In a collaboration with Michela Gallagher, my work in this area focuses on examining the single-unit activity of neurons in the lateral entorhinal cortex to unveil what kinds of information the lateral entorhinal cortex may conveys to the hippocampus and how it may be altered by the structural and molecular changes that occur during aging.
  • undergraduate students

  • Ruo-Yah Lai

    Ruo-Yah Lai

  • lab staff

  • Kimberly Nnah

    Kimberly Nnah

    Research Technologist

  • 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.
  • Kelly Wright

    Kelly Wright

    Research Technologist

  • collaborators

  • Kim Christian

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

  • Noah Cowan

    Associate Professor, Department of Mechanical Engineering, Johns Hopkins University

  • Kathleen Cullen

    Professor, Department of Biomedical Engineering, Whiting School of Engineering

  • Shahin Gharakozlou Lashkari

    Shahin Gharakozlou Lashkari

    • Research Interests: Shahin Gharakozlou Lashkari is a PhD student in Prof. Noah Cowan's LIMBS Lab at JHU. He is interested in the electrophysiological study of hippocampal place cells during complex navigational tasks.
  • Katie Hedrick

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

  • Ravikrishnan Jayakumar

    Ravikrishnan Jayakumar

    • rperurj1@jhu.edu
    • Research Interests: Ravi Jayakumar is a postdoctoral fellow 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. His path into neuroscience has had unusual origins with a Bachelors in Mechanical Engineering, a stint at an automobile MNC, a Masters specializing in Robotics and eventually joining Prof. Noah Cowan's lab from whom he received training in the mathematical methods of system identification in complex biological systems. Multiple close collaborative projects between Noah & Jim included the combined mentorship of Ravi, leading to this unholy amalgamation of an engineer and neuroscientist.
  • Sang Hoon Kim

    Postdoctoral Research Fellow, University of Pennsylvania

  • Gorkem Secer

    Gorkem Secer

    • gsecer1@jhu.edu
    • Research Interests: Gorkem Secer is a postdoctoral fellow in Prof. Noah Cowan's LIMBS Lab at JHU. He has a PhD in computer science. Coming from a controls and signal processing background, he is now transitioning to neuroscience. His current project seeks to understand the role of the hippocampus in motion planning and decision-making.
  • 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

  • Xiaojing Chen

    Assistant Professor, South University of Science and Technology, Shenzhen, China

  • 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

  • Marissa Ferreyros

  • Doug Goodsmith

    Postdoctoral Research Fellow, University of Pennsylvania

  • 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

  • Francesco Savelli

    Assistant Professor, Department of Biology, University of Texas at San Antonio

  • Jennifer Siegel

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

  • Arjuna Tillekeratne

    Research Technologist

  • Horatiu Voicu

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

  • Cheng Wang

    Principal Investigator, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China

  • Chia-Hsuan Wang

  • Xintian Yu

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