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Ph.D., Indian Institute
of Science
Assistant Professor
Department of Neuroscience
564 Sidney Frank Hall of Life Sciences
Tel: (401) 863-9727
Email: Mayank_Mehta@brown.edu
Go to lab web page
We routinely learn
to go from a place 'A' to a neighboring 'B', often within a single
trial, even in highly unfamiliar environments. We are interested
in understanding how such maps of the world are learned and remembered.
Learning is believed mediated by synaptic plasticity. Research
in the past three decades has shown that synaptic plasticity depends
critically on the relative spike timing of neurons. Do neuronal
activity patterns, that are required for synaptic plasticity,
occur during behavior? If so, do they induce synaptic plasticity?
What are the effects of synaptic plasticity on the structure and
activity of complex neuronal networks and behavior?
To address these questions, we record the activity of a large
number of neurons from the hippocampus and related cortical regions
during behavior. Hippocampal neurons fire selectively as a function
of the animal's spatial location, and the hippocampal synapses
show synaptic plasticity. Hence, we have set up computational
models of learning spatial maps via synaptic plasticity. Our models
suggest that oscillations are critical for generating the neuronal
activity patterns required for synaptic plasticity. Further, these
models predict that synaptic plasticity would make the hippocampal
place fields more asymmetric and ''anticipatory' with experience,
that could allow an animal to predict the upcoming spatial location
based on past experience. Data from our lab, as well as from other
labs, support these computational hypotheses. The results generalize
easily to learning temporal sequences in other parts of the cortex
as well, and pave the way towards a better understanding of mechanisms
of learning and memory in neural networks.
K. L. Hoffman, F. P. Battaglia, K. Harris, J.N MacLean, L. Marshall and M. R. Mehta. ‘The upshot of up-states in the neocortex: from slow oscillations to memory formation’. J. Neurosci. 27: 11838 - 11841 (2007).
M. R. Mehta. “Fascinating rhythm” Nature 446: 27 (2007).
M. R. Mehta, ‘Cortico-hippocampal interaction in up-down states and memory consolidation’. Nature Neuroscience 10:13-15 (2007).
T. T. G. Hahn, B. Sakmann and M. R. Mehta, 'Differential response of hippocampal sub-fields to cortical up-down states’. PNAS 104: 5169-74 (2007).
T. T. G Hahn, B. Sakmann, M. R. Mehta. ‘Phase locking of hippocampal interneuron’s membrane potential to neocortical up-down states’. Nature Neuroscience, 9: 1359:1361 (2006).
M. R. Mehta ‘Role of rhythms in facilitating short-term memory’, Neuron 45, 7:9 (2005).
M.R. Mehta ‘Cooperative LTP can map memory sequences on dendritic branches’. TINS, 27 69:72 (2004).
C. C. Petersen, T. Hahn, M. R. Mehta, A. Grinwald & B. Sakmann, ‘Interaction of sensory responses with spontaneous depolarisation in layer 2/3 barrel cortex’. PNAS 100: 13638-13643 (2003).
M. R. Mehta, A. K. Lee & M. A. Wilson, 'Role of Oscillations and Experience in Transforming a Rate Code into a Temporal Code'. Nature, 417:741-746 (2002).
Mayank R. Mehta,'Neuronal Dynamics of Predictive Coding' Neuroscientist, 7(6): 490-495 (2001)
M. R. Mehta & M. A. Wilson, 'From Hippocampus to V1: Effect of LTP on Spatio-Temporal Dynamics of Receptive Fields', Neurocomputing 32:905-911 (2000).
M. R. Mehta, M. C. Quirk & M. A. Wilson, 'Experience-Dependent Asymmetric Shape of Hippocampal Receptive Fields', Neuron 25:707-715 (2000).
For more publications visit the Mehta Lab web page
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