Oscillatory dynamics and place field maps reflect hippocampal ensemble processing of sequence and place memory under NMDA receptor control

• Published in: Neuron (Cambridge, Mass.) Vol. 81; no. 2; pp. 402 - 415
• Main Authors: Cabral, Henrique O, Vinck, Martin, Fouquet, Celine, Pennartz, Cyriel M A, Rondi-Reig, Laure, Battaglia, Francesco P
• Format: Journal Article
• Language: English
• Published: United States Elsevier Limited 22-01-2014; Elsevier
• Subjects: Action Potentials - physiology; Analysis of Variance; Animals; Biological Clocks - physiology; Brain Waves - physiology; Carrier Proteins - genetics; Carrier Proteins - metabolism; Confidence intervals; Expected values; Hippocampus - cytology; Hippocampus - physiology; Life Sciences; Maze Learning - physiology; Memory; Memory - physiology; Mice; Mice, Knockout; Nerve Tissue Proteins - genetics; Nerve Tissue Proteins - metabolism; Neurons; Neurons - physiology; Neurons and Cognition; Nonlinear Dynamics; Patch-Clamp Techniques; Receptors, N-Methyl-D-Aspartate; Rodents; Serial Learning - physiology; Space Perception - physiology; Spectrum Analysis
• ISSN: 0896-6273; 1097-4199
• DOI: 10.1016/j.neuron.2013.11.010

Place coding in the hippocampus requires flexible combination of sensory inputs (e.g., environmental and self-motion information) with memory of past events. We show that mouse CA1 hippocampal spatial representations may either be anchored to external landmarks (place memory) or reflect memorized sequences of cell assemblies depending on the behavioral strategy spontaneously selected. These computational modalities correspond to different CA1 dynamical states, as expressed by theta and low- and high-frequency gamma oscillations, when switching from place to sequence memory-based processing. These changes are consistent with a shift from entorhinal to CA3 input dominance on CA1. In mice with a deletion of forebrain NMDA receptors, the ability of place cells to maintain a map based on sequence memory is selectively impaired and oscillatory dynamics are correspondingly altered, suggesting that oscillations contribute to selecting behaviorally appropriate computations in the hippocampus and that NMDA receptors are crucial for this function.