Distinct pattern separation related transfer functions in human CA3/dentate and CA1 revealed using high-resolution fMRI and variable mnemonic similarity
- 1Center for the Neurobiology of Learning and Memory, Department of Neurobiology and Behavior, University of California, Irvine, Irvine, California 92697, USA
- 2Department of Radiological Sciences, Center for Functional Onco Imaging, University of California, Irvine, California 92697, USA
Abstract
Producing and maintaining distinct (orthogonal) neural representations for similar events is critical to avoiding interference in long-term memory. Recently, our laboratory provided the first evidence for separation-like signals in the human CA3/dentate. Here, we extended this by parametrically varying the change in input (similarity) while monitoring CA1 and CA3/dentate for separation and completion-like signals using high-resolution fMRI. In the CA1, activity varied in a graded fashion in response to increases in the change in input. In contrast, the CA3/dentate showed a stepwise transfer function that was highly sensitive to small changes in input.
Footnotes
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↵3 Corresponding author.
E-mail cestark{at}uci.edu; fax (949) 824-2447.
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[Supplemental material is available for this article.]
- Received August 4, 2010.
- Accepted October 10, 2010.
- © 2011 Cold Spring Harbor Laboratory Press
