These studies of learning and memory in awake, behaving animals have led to the exploration of the nature of sleep and its role in memory. Previous theories have suggested that sleep states may be involved in the process of memory consolidation, in which memories are transferred from short to longer-term stores and possibly reorganized into more efficient forms. Recent evidence has shown that ensembles of neurons within the hippocampus, which had been activated during behavior are reactivated during periods of dreaming. By reconstructing the content of these states, specific memories can be tracked during the course of the consolidation process.
Combining the measurement of ongoing neuronal activity with manipulation of molecular genetic targets has allowed the study of how specific cellular mechanisms regulate neural function to produce learning and memory at the behavioral level. Pharmacological blockage of these receptors has allowed the study of their involvement in the rapid changes that occur during both waking and sleeping states. Simultaneous monitoring of areas in the hippocampus and neocortex have allowed study of the downstream effects of activation.
Taken together, these approaches contribute to the overall research objective: to understand the link from cellular/subcellular mechanisms of plasticity, to neural ensemble representations and interactions, to learning, memory, behavior, and cognition.
Mehta, M.R., Lee, A.K., Wilson, M.A., “Role of experience and oscillations in transforming a rate code into a temporal code”, Nature , 417 :741-746, 2002.
Nakazawa, K., Quirk, M.C., Chitwood, R.A., Watanabe, M., Yeckel, M.F., Sun, L.D., Kato, A., Carr, C.A., Johnston, D., Wilson, M.A., Tonegawa, S., “Requirement for hippocampal CA3 NMDA receptors in associative memory recall”, Science, 297 :211-218, 2002.
Lee, A.K., Wilson, M.A., “Memory of Sequential Experience in the Hippocampus During Slow Wave Sleep”, Neuron, 36 :1183-1194, 2002.
Nakazawa, K., Sun, L.D., Quirk, M.C., Rondi-Reig, L., Wilson, M.A., Tonegawa, S., “Hippocampal CA3 NMDA receptors are crucial for memory acquisition of one-time experience”, Neuron, 38 :305-315, 2003.
Lee, A.K., Wilson, M.A., “A Combinatorial Method for Analyzing Sequential Firing Patterns Involving an Arbitrary Number of Neurons Based on Relative Time Order.” J Neurophysiol. 92 :2555-2573, 2004.
Barbieri, R., Wilson, M.A., Frank, L.M., Brown E.N., “An analysis of hippocampal spatio-temporal representations using a Bayesian algorithm for neural spike train decoding.”, IEEE Trans Neural Syst Rehabil Eng. 13 :131-6, 2005.
Jones, M.W., Wilson, M.A., “Theta Rhythms Coordinate Hippocampal-Prefrontal Interactions in a Spatial Memory Task”, Public Library of Science, 3 :2187-99, 2005.
Foster, D.J., Wilson, M.A., “Reverse replay of behavioural sequences in hippocampal place cells during the awake state.”, Nature, 440 :680-3. Epub Feb. 12, 2006.
Ji, D., Wilson, M.A., "Coordinated memory replay in the visual cortex and hippocampus during sleep", Nature Neuroscience, 10 :100-107, 2007.