There are a substantial number of studies showing that the orbitofrontal cortex links events to reward values, whereas the hippocampus
links events to the context in which they occur. Here we asked how the orbitofrontal cortex contributes to memory where context
determines the reward values associated with events. After rats learned object–reward associations that differed depending on the spatial
context in which the objects were presented, neuronal ensembles in orbitofrontal cortex represented distinct value-based schemas, each
composed of a systematic organization of the representations of objects in the contexts and positions where they were associated with
reward or nonreward. Orbitofrontal ensembles also represent the different spatial contexts that define the mappings of stimuli to
actions that lead to reward or nonreward. These findings, combined with observations on complementary memory representation
within the hippocampus, suggest mechanisms through which prefrontal cortex and the hippocampus interact in support of
context-guided memory.
Anja Farovik, Ryan Place, Samuel McKenzie, Blake Porter, Catherine Munro, and Howard Eichenbaum. Orbitofrontal cortex encodes memories within value-based schemas and represents contexts that guide memory retrieval. Journal of Neuroscience. 27 May 2015. 35(21): 8333-8344. doi: 10.1523/JNEUROSCI.0134-15.2015
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