James Knierim

James Knierim is a Professor of Neuroscience at the Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, and a researcher at the Zanvyl Krieger Mind/Brain Institute. His laboratory investigates the neurophysiology of memory and spatial navigation in the hippocampal formation using advanced techniques such as multi-electrode recordings, optogenetics, and virtual reality systems like the Dome apparatus.

• PhD, California Institute of Technology
• BA, Psychology, Haverford College

Dr. Knierim's research focuses on how the brain forms cognitive maps of the environment through the activity of place cells, grid cells, and head direction cells. His work explores the roles of the medial and lateral entorhinal cortex in providing allocentric spatial context and egocentric content representations, respectively, which are integrated in the hippocampus to form episodic memories. He investigates neural computations such as pattern separation and pattern completion across hippocampal subfields (DG, CA3, CA1), and how these processes are affected by aging. His lab also studies path integration and its recalibration through sensory feedback.

The recent publications from his lab span topics including neural coding in the dentate gyrus, functional heterogeneity in CA3, aging-related neural changes, multiplexing of spatial and temporal information, and closed-loop control of place cells. These works reflect a strong trend toward integrating behavioral paradigms with computational modeling and advanced neurophysiological techniques to understand memory and navigation at the systems level.

Notable scientific contributions include:

• Discovery of functional differences between CA1 and CA3 place cells supporting attractor network theories
• Demonstration of non-spatial coding in the lateral entorhinal cortex
• First physiological demonstration of path integration recalibration in freely moving rodents
• Identification of distinct firing properties of dentate gyrus mossy cells vs. granule cells

Dr. Knierim mentors a team of postdoctoral fellows and graduate students and collaborates with researchers in engineering, psychology, and biomedical sciences. His lab is supported by grants from the NIH and DOD, enabling interdisciplinary projects on neural basis of navigation and memory. He has trained numerous former lab members who have gone on to faculty and research positions worldwide.

The Knierim Lab operates within the Zanvyl Krieger Mind/Brain Institute and collaborates closely with the LIMBS Lab in Mechanical Engineering, reflecting a strong interdisciplinary approach to understanding brain function. The lab utilizes cutting-edge tools including Neuropixels probes, miniscopes for calcium imaging, and the Dome virtual reality system for studying freely moving rodents.