The mind is thought to be the emergent property of the activities of ensembles of neurons. The nature of these emergent properties and how they arise are unknown. This is the focus of our research. In particular, our current research addresses the following fundamental questions in Neurophysics: 1. How is information about the physical world represented by ensembles of neurons? In particular, what are the neural mechanisms of perceiving space-time? 2. How do the neural representations evolve with learning? 3. What is the role of brain rhythms in learning and memory? 4. How does sleep influence learning? To address these questions we use both experimental and theoretical approaches as follows: 1. Develop hardware to measure and manipulate neural activity and behavior. 2. Measure the activity of ensembles of well isolated neurons from many hippocampal and neocortical areas simultaneously during learning and during sleep. 3. Develop data analysis tools to decipher the patterns of neural activity and field potentials, and their relationship to behavior. 4. Develop biophysical theories of synapses, neurons and neuronal networks that can explain these experimental finding, relate them to the underlying cellular mechanisms, and make experimentally testable predictions. The results would not only provide fundamental understanding of neural ensemble dynamics but also point to novel ways of treating learning and memory disorders.

Jason J. Moore, Pascal M. Ravassard, David Ho, Lavanya Acharya, Ashley L. Kees, Cliff Vuong, Mayanak R. Mehta.  Dynamics of Cortical Dendritic Membrane Potential and Spikes in Freely Behaving Cats.  Science, vol 335, issue 6331, 1281 (2017), 24 March 2017.

Acharya Lavanya, Aghajan Zahra M, Vuong Cliff, Moore Jason J, Mehta Mayank R Causal Influence of Visual Cues on Hippocampal Directional Selectivity Cell, 2016; 164(1-2): 197-207.

Mehta Mayank R From synaptic plasticity to spatial maps and sequence learning Hippocampus, 2015; 25(6): 756-62.

Aghajan Zahra M, Acharya Lavanya, Moore Jason J, Cushman Jesse D, Vuong Cliff, Mehta Mayank R Impaired spatial selectivity and intact phase precession in two-dimensional virtual reality Nature neuroscience, 2015; 18(1): 121-8.

Ravassard Pascal, Kees Ashley, Willers Bernard, Ho David, Aharoni Daniel, Cushman Jesse, Aghajan Zahra M, Mehta Mayank R Multisensory control of hippocampal spatiotemporal selectivity Science (New York, N.Y.), 2013; 340(6138): 1342-6.

Cushman Jesse D, Aharoni Daniel B, Willers Bernard, Ravassard Pascal, Kees Ashley, Vuong Cliff, Popeney Briana, Arisaka Katsushi, Mehta Mayank R Multisensory control of multimodal behavior: do the legs know what the tongue is doing? PloS one, 2013; 8(11): e80465.

Ghorbani Maryam, Mehta Mayank, Bruinsma Robijn, Levine Alex J Nonlinear-dynamics theory of up-down transitions in neocortical neural networks Physical review. E, Statistical, nonlinear, and soft matter physics, 2012; 85(2 Pt 1): 021908.

Ahmed Omar J, Mehta Mayank R Running speed alters the frequency of hippocampal gamma oscillations The Journal of neuroscience : the official journal of the Society for Neuroscience, 2012; 32(21): 7373-83.

Hahn Thomas T G, McFarland James M, Berberich Sven, Sakmann Bert, Mehta Mayank R Spontaneous persistent activity in entorhinal cortex modulates cortico-hippocampal interaction in vivo Nature neuroscience, 2012; 15(11): 1531-8.

Resnik Evgeny, McFarland James M, Sprengel Rolf, Sakmann Bert, Mehta Mayank R The effects of GluA1 deletion on the hippocampal population code for position The Journal of neuroscience : the official journal of the Society for Neuroscience, 2012; 32(26): 8952-68.

Mehta Mayank R Contribution of Ih to LTP, place cells, and grid cells Cell, 2011; 147(5): 968-70.

McFarland James M, Hahn Thomas T G, Mehta Mayank R Explicit-duration hidden Markov model inference of UP-DOWN states from continuous signals PloS one, 2011; 6(6): e21606.

Kumar Arvind, Mehta Mayank R Frequency-Dependent Changes in NMDAR-Dependent Synaptic Plasticity Frontiers in computational neuroscience, 2011; 5(5): 38.

Chen Zhiping, Resnik Evgeny, McFarland James M, Sakmann Bert, Mehta Mayank R Speed controls the amplitude and timing of the hippocampal gamma rhythm PloS one, 2011; 6(6): e21408.

Ahmed Omar J, Mehta Mayank R The hippocampal rate code: anatomy, physiology and theory Trends in neurosciences, 2009; 32(6): 329-38. Mehta Mayank R Cortico-hippocampal interaction during up-down states and memory consolidation Nature neuroscience, 2007; 10(1): 13-5.

Hahn Thomas T G, Sakmann Bert, Mehta Mayank R Differential responses of hippocampal subfields to cortical up-down states Proceedings of the National Academy of Sciences of the United States of America, 2007; 104(12): 5169-74.

Hoffman Kari L, Battaglia Francesco P, Harris Kenneth, MacLean Jason N, Marshall Lisa, Mehta Mayank R The upshot of up states in the neocortex: from slow oscillations to memory formation The Journal of neuroscience : the official journal of the Society for Neuroscience, 2007; 27(44): 11838-41.

Hahn Thomas T G, Sakmann Bert, Mehta Mayank R Phase-locking of hippocampal interneurons’ membrane potential to neocortical up-down states Nature neuroscience, 2006; 9(11): 1359-61.

Mehta Mayank R Role of rhythms in facilitating short-term memory Neuron, 2005; 45(1): 7-9.

Mehta Mayank R Cooperative LTP can map memory sequences on dendritic branches Trends in neurosciences, 2004; 27(2): 69-72.

Petersen Carl C H, Hahn Thomas T G, Mehta Mayank, Grinvald Amiram, Sakmann Bert Interaction of sensory responses with spontaneous depolarization in layer 2/3 barrel cortex Proceedings of the National Academy of Sciences of the United States of America, 2003; 100(23): 13638-43.