Control of CA3 Place Fields by the Dentate Gyrus: A Neural Network Model

  • Ali A. Minai


A very interesting aspect of hippocampal anatomy is the presence of two pathways projecting from the entorhinal cortex (EC) to the CA3 region — one directly via the perforant path (PP), and the other through the dentate gyms (DG) using the mossy fibers of the granule cells. This implies that the place fields of the CA3 arise from the joint influence of EC and DG. We hypothesize that the DG plays a modulatory role in this scheme, serving to enhance discrimination during the learning of new place codes. Drawing in part on some receny experimental findings, we model a mechanism whereby DG neurons accomplish pattern separation by modulating the balance of dendritic and somatic inhibition in granule cells. Our results are consistent with a variety of observations in the literature, including the following: 1) DG lesions do not abolish CA3 place fields but disrupt spatial memory; 2) Even similar environments produce different place fields in CA3 but not in the EC. We show that DG modulation allows the model hippocampus to control spatial discrimination, and produces realistic place fields.


Granule Cell Dentate Gyrus Entorhinal Cortex Mossy Fiber Place Field 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. [1]
    Buckmaster, P.S., and Schwartzkroin, P.A. (1994) Hippocampal mossy cell function: A speculative view. Hippocampus 4: 393–402.CrossRefGoogle Scholar
  2. [2]
    Gibson, W.G., Robinson, J., and Bennett, M.R. (1991) Probabilistic secretion of quanta in the central nervous system: Granule cell synaptic control of pattern separation and activity regulation. Phil Trans. R.. Soc. Lond. B 332: 199–220.CrossRefGoogle Scholar
  3. [3]
    Hasselmo, M.E. (1993). Acetylcholine and learning in a cortical associative memory. Neural Computation 5: 32–44.CrossRefGoogle Scholar
  4. [4]
    Knierim, J.J., and McNaughton, B.L. (1995) Differential effects of dentate gyms lesions on pyramidal cell firing in 1- and 2-dimensional spatial tasks. Soc. Neurosci. Abstr. 21: 940.Google Scholar
  5. [5]
    Mar-, D. (1969) Simple memory: A theory for archicortex. Phil. Trans. R. Soc. Lond. B) 262: 23–81.CrossRefGoogle Scholar
  6. [6]
    McNaughton, B.L., Barnes, C.A., Meltzer, J., and Sutherland, R.J. (1989). Hippocampal granule cells are necessary for normal spatial learning but not for spatially-selective pyramidal cell discharge. Exp. Brain Res. 76: 485–496.PubMedCrossRefGoogle Scholar
  7. [7]
    McNaughton, B.L., Barnes, C.A., Gerrard, J.L., Gothard, K., Jung, M.W., Knierim, J.J., Kudrimoti, H., Qin, Y., Skaggs, W.E., Suster, M., and Weaver, K.L. (1996) Deciphering the hippocampal polyglot: The hippocampus as a path integration system. J. Exper. Biol. 199: 173–185.Google Scholar
  8. [8]
    O’Reilly, R.C., and McClelland, J.L. (1994). Hippocampal conjunctive encoding, storage and recall: Avoiding a tradeoff. Tech. Rep. PDP.CNS.94. 4. PDP and CNS Group: Pittsburgh, PA.Google Scholar
  9. [9]
    Quirk, G.J., Muller, R.U., Kubie, J.L., and Ranck, J.B., Jr. (1992). The positional firing properties of medial entorhinal neurons: Description and comparison with hippocampal place cells. J. Neurosci. 12: 1945–1963-Google Scholar
  10. [10]
    Rolls, E. (1989). The representation and storage of information in neuronal networks in the primate cerebral cortex and hippocampus. In: The Computing Neuron, Rolls, E (eds.) 125–159, Addison-Wesley.Google Scholar
  11. [1.
    ] Thompson, L.T., and Best, P.J. (1989). Place cells and silent cells in the hippocampus of freely-behaving rats. J. Neurosci. 9: 2382–2390.PubMedGoogle Scholar
  12. [12]
    Touretzky, D.S., and Redish, A.D. (1996) Theory of rodent navigation based on interacting representations of space. Hippocampus 6: 247–270.PubMedCrossRefGoogle Scholar
  13. [13]
    Treves, A., and Rolls, E.T. (1992). Computational constraints suggest the need for two distinct input systems to the hippocampal CA3 network. Hippocampus 2: 189–200.PubMedCrossRefGoogle Scholar
  14. [14]
    Yeckel, M.F., and Berger, T.W. (1990). Feedforward excitation of the hippocampus afferents from the entorhinal cortex: Redefinition of the role of the trisynaptic pathway. Proc. Nat. Acad. Sci. 87: 5832–5836.PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1997

Authors and Affiliations

  • Ali A. Minai
    • 1
  1. 1.Complex Adaptive Systems Laboratory, Department of Electrical and Computer Engineering and Computer ScienceUniversity of CincinnatiCincinnatiUSA

Personalised recommendations