TY - JOUR
T1 - Dentate gyrus mossy cells share a role in pattern separation with dentate granule cells and proximal CA3 pyramidal cells
AU - GoodSmith, Douglas
AU - Lee, Heekyung
AU - Neunuebel, Joshua P.
AU - Song, Hongjun
AU - Knierim, James J.
N1 - Funding Information:
Received April 26, 2019; revised Sept. 26, 2019; accepted Oct. 3, 2019. Authorcontributions:D.G.,H.S.,andJ.J.K.designedresearch;D.G.analyzeddata;D.G.wrotethefirstdraftofthe paper; D.G., H.L., J.P.N., H.S., and J.J.K. edited the paper; D.G. and J.J.K. wrote the paper; H.L. and J.P.N. performed research. This work was supported by National Institutes of Health Grants RO1 NS039456, T32 NS091018, and R37 NS047344. We thank Sachin Deshmukh, Cheng Wang, and Kimberly Nnah for advice and assistance. The authors declare no competing financial interests. Correspondence should be addressed to Douglas GoodSmith at d.goodsmith@gmail.com or James J. Knierim at jknierim@jhu.edu. J.P. Neunuebel’s present address: Psychological and Brain Sciences, University of Delaware, Newark, DE 19716. https://doi.org/10.1523/JNEUROSCI.0940-19.2019 Copyright © 2019 the authors
Publisher Copyright:
Copyright © 2019 the authors
PY - 2019/11/27
Y1 - 2019/11/27
N2 - The complementary processes of pattern completion and pattern separation are thought to be essential for successful memory storage and recall. The dentate gyrus (DG) and proximal CA3 (pCA3) regions have been implicated in pattern separation, in part through extracellular recording studies of these areas. However, the DG contains two types of excitatory cells: granule cells of the granule layer and mossy cells of the hilus. Little is known about the firing properties of mossy cells in freely moving animals, and it is unclear how their activity may contribute to the mnemonic functions of the hippocampus. Furthermore, tetrodes in the dentate granule layer and pCA3 pyramidal layer can also record mossy cells, thus introducing ambiguity into the identification of cell types recorded. Using a random forests classifier, we classified cells recorded in DG (Neunuebel and Knierim, 2014) and pCA3 (Lee et al., 2015) of 16 male rats and separately examined the responses of granule cells, mossy cells, and pCA3 pyramidal cells in a local/global cue mismatch task. All three cell types displayed low correlations between the population representations of the rat’s position in the standard and cue-mismatch sessions. These results suggest that all three excitatory cell types within the DG/pCA3 circuit may act as a single functional unit to support pattern separation.
AB - The complementary processes of pattern completion and pattern separation are thought to be essential for successful memory storage and recall. The dentate gyrus (DG) and proximal CA3 (pCA3) regions have been implicated in pattern separation, in part through extracellular recording studies of these areas. However, the DG contains two types of excitatory cells: granule cells of the granule layer and mossy cells of the hilus. Little is known about the firing properties of mossy cells in freely moving animals, and it is unclear how their activity may contribute to the mnemonic functions of the hippocampus. Furthermore, tetrodes in the dentate granule layer and pCA3 pyramidal layer can also record mossy cells, thus introducing ambiguity into the identification of cell types recorded. Using a random forests classifier, we classified cells recorded in DG (Neunuebel and Knierim, 2014) and pCA3 (Lee et al., 2015) of 16 male rats and separately examined the responses of granule cells, mossy cells, and pCA3 pyramidal cells in a local/global cue mismatch task. All three cell types displayed low correlations between the population representations of the rat’s position in the standard and cue-mismatch sessions. These results suggest that all three excitatory cell types within the DG/pCA3 circuit may act as a single functional unit to support pattern separation.
KW - Dentate gyrus
KW - Granule cells
KW - Hippocampus
KW - Mossy cells
KW - Pattern separation
KW - Single-unit recording
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U2 - 10.1523/JNEUROSCI.0940-19.2019
DO - 10.1523/JNEUROSCI.0940-19.2019
M3 - Article
C2 - 31641051
AN - SCOPUS:85075813854
SN - 0270-6474
VL - 39
SP - 9570
EP - 9584
JO - Journal of Neuroscience
JF - Journal of Neuroscience
IS - 48
ER -