Functional Insights about Synaptic Inputs to Dendrites

  • Wilfrid Rall


This talk briefly reviewed results of earlier computations that simulated synaptic inputs to passive dendritic membrane. Then it reviewed dendritic spines and the possibility that some spine heads might have excitable membrane properties. Because some neurons have dendritic arbors that are studded with hundreds or thousands of spines, computations were used to explore theoretical examples of different synaptic input combinations to both excitable and passive spines. The results demonstrate the possibility of synaptic amplification by action potentials in spine heads, and the possibility of chain reactions between excitable spines. These nonlinear responses could be used for logical processing of inputs in dendritic arbors. Dendro-dendritic synapses were also reviewed briefly; they provide the possibility of graded synaptic interactions between dendritic arbors of different neurons, (without the constraint of all-or-nothing impulses). These examples of modeling and computations based on anatomy and physiology demonstrate both a richness of possibilities and a challenge to future modeling of neurons and networks of neurons. The details below are quite brief; more complete presentations with illustrations are available in the references cited.


Granule Cell Dendritic Spine Synaptic Input Dendritic Arbor Mitral Cell 
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. Klee, M. & W. Rall (1977) Computed potentials of cortically arranged populations of neurons. J. Neurophysiol. 40: 647–666.Google Scholar
  2. Miller, J.P., W. Rall & J. Rinzel (1985) Synaptic amplification by active membrane in dendritic spines. Brain Res. 325: 325–330.CrossRefGoogle Scholar
  3. Perkel, D.H. & D.J. Perkel (1985) Dendritic spines: Role of active membrane in modulating synaptic efficacy. Brain Res. 325: 331–335.CrossRefGoogle Scholar
  4. Rall, W. (1964) Theoretical significance of dendritic trees for neuronal input-output relations. In: Neural Theory and Modeling, R.F. Reiss, ed. Stanford University Press, pp. 73–97.Google Scholar
  5. Rall, W. (1970) Dendritic neuron theory and dendro-dendritic synapses in a simple cortical system. In:The Neurosciences: Second Study Program, F.O. Schmitt, ed. New York, Rockefeller Press, pp 552–565.Google Scholar
  6. Rall, W. (1977) Core conductor theory and cable properties of neurons. In: Handbook of Physiology, Cellular Biology of Neurons, Kandel, E.R., Brookhardt, J.M., & Mountcastle, V.B., eds. Bethesda, Am. Physiol. Soc. pp 39–97.Google Scholar
  7. Rall, W. (1989) Cable theory for dendritic neurons. In: Methods in Neuronal Modeling; from Synapses to Networks, C. Koch & I. Segev, eds. Cambridge, MIT Press, pp 9–62.Google Scholar
  8. Rall, W. (1990) Perspectives on neural modeling. In: The Segmental Motor System, M.D. Binder & L.M. Mendell eds. Oxford University Press, pp 129–149.Google Scholar
  9. Rall, W. & J. Rinzel (1973) Branch input resistance and steady attenuation for input to one branch of a dendritic neuron model. Biophys. J. 13: 648–688.CrossRefGoogle Scholar
  10. Rall, W. k I. Segev (1987) Functional possibilities for synapses on dendrites and dendritic spines. In: Synpatic Function, G.M. Edleman, W.E. Gall & W.M. Cowan, eds. New York, Wiley, pp 605–636.Google Scholar
  11. Rall, W. & I. Segev (1988a) Synaptic integration and excitable dendritic spine clusters: structure/function. In: Intrinsic Determinants of Neuronal Form and Function, R.J. Lasek & M.M. Black, eds. New York, Alan R. Liss, pp 263–282.Google Scholar
  12. Rall, W. k I. Segev (1988b) Dendritic spine synapses, excitable spine clusters and plasticity. In: Cellular Mechanisms of Conditioning and Behavioral Plasticity, CD. Woody, D. L. Alkon & J. L. McGaugh, eds. New York, Plenum Press, pp 221–236.Google Scholar
  13. Rall, W. k I. Segev (1988c) Excitable dendritic spine clusters: nonlinear synaptic processing. In: Computer Simulation in Brain Science, R.M.J. Cotterill, ed. Cambridge University Press, pp 26–43.Google Scholar
  14. Rall, W. k I. Segev (1990) Dendritic branches, spines, synapses and excitable spine clusters. In: Computational Neuroscience, E.L. Schwartz, ed. New York, MIT Press, pp 69–81.Google Scholar
  15. Rall, W., k G.M. Shepherd (1968) Theoretical reconstruction of field potentials and dendrodendritic synaptic interactions in olfactory bulb. J. Neurophysiol. 31: 884–915.Google Scholar
  16. Rall, W., G.M. Shepherd, T.S. Reese, & M.W. Brightman (1966) Dendrodendritic synaptic pathway for inhibition in the olfactory bulb. Exptl. Neurol. 14: 44–56.CrossRefGoogle Scholar
  17. Segev, I. k W. Rall (1988) Computational study of an excitable dendritic spine. J. Neurophysiol. 60: 499–523.Google Scholar
  18. Shepherd, G.M. & R.K. Brayton (1987) Logic operations are properties of computer-simulated interactions between active dendritic spines. Neuroscience 21: 151–165.CrossRefGoogle Scholar
  19. Shepherd, G.M., R.K. Brayton, J.P. Miller, I. Segev, J. Rinzel & W. Rall (1985) Signal enhancement in distal cortical dendrites by means of interaction between active dendritic spines. Proc. Nat. Acad. Sci. 82: 2192–2195.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1992

Authors and Affiliations

  • Wilfrid Rall
    • 1
  1. 1.Mathematical Research BranchNIDDK, NIHBethesda

Personalised recommendations