title: Distinct pattern separation related transfer functions in human CA3/dentate and CA1 revealed using high-resolution fMRI and variable mnemonic similarity.
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.
authors.affiliation: Center for the Neurobiology of Learning and Memory, Department of Neurobiology and Behavior, University of California, Irvine, Irvine, California 92697, USA.
authors.forename: Joyce W
authors.initials: JW
authors.lastname: Lacy
authors.forename: Michael A
authors.initials: MA
authors.lastname: Yassa
authors.forename: Shauna M
authors.initials: SM
authors.lastname: Stark
authors.forename: L Tugan
authors.initials: LT
authors.lastname: Muftuler
authors.forename: Craig E L
authors.initials: CE
authors.lastname: Stark
mesh_terms: D000704:Analysis of Variance; D001931:Brain Mapping; D056547:CA1 Region, Hippocampal / Q000098:blood supply / Q000502:physiology; D056654:CA3 Region, Hippocampal / Q000098:blood supply / Q000502:physiology; D018891:Dentate Gyrus / Q000098:blood supply / Q000502:physiology; D004192:Discrimination, Psychological; D006624:Hippocampus / Q000033:anatomy & histology / Q000098:blood supply / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging; D008568:Memory / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D011930:Reaction Time / Q000502:physiology; D014163:Transfer, Psychology / Q000502:physiology*
chemical_list: D010100:Oxygen