Advertisement

Experimental Brain Research

, Volume 33, Issue 3–4, pp 371–394 | Cite as

Prominent excitatory pathways in the cat visual cortex (A 17 and A 18): A current source density analysis of electrically evoked potentials

  • U. Mitzdorf
  • W. Singer
Article

Summary

The current source density (CSD) method in its one-dimensional approximation is used to analyze the field potentials in visual areas 18 and 17 of the cat, which were elicited by stimulating electrodes in the optic chiasm (OX), the optic radiation (OR) or in the respective cortical area itself. The CSD analysis reveals the basic pattern of excitatory postsynaptic activity.
  1. 1.

    In both visual areas the basic specific excitatory activity flows along three different intracortical pathways, all starting in layer IV: The first pathway relays activity from layer IV to supragranular pyramidal cells via strong, local connections to layer III and from there through long-distance connections to layer II. The second pathway conveys activity from layer IV to layer V, where it mainly contacts apical dendrites of layer VI pyramidal cells. This infragranular polysynaptic activity is not clearly resolvable into separate components, suggesting that it is conveyed by various groups of axons, among them long-distance horizontal connections. The third pathway has one synaptic relay within layer IV and then conveys activity to layer III. In addition, monosynaptic activity is revealed in layers VI and I.

     
  2. 2.

    In A 18 one coherent, fast-conducting group of afferents induces this basic activity pattern. In A 17 no such fast conducting input is resolvable; the supragranular activity is induced by a small group of afferents with intermediate conduction velocity, which terminate in the upper part of layer IV. The infragranular activity is induced by afferents with slower and widely scattered conduction velocities, which terminate in the lower part of layer IV. The layer VI input is very prominent in A 17 and also has a wide latency scatter.

     
  3. 3.

    The supragranular activity is more prominent in A 18 than in A 17 and the respective layers appear thicker, in accordance with anatomy. In A 17 the infragranular activity prevails and layers IV and VI appear very broad, again in accordance with anatomy.

     
  4. 4.

    Comparison of the CSDs with the original evoked potentials shows that the surface evoked potentials over A 18 reflect the three dipolar sink/source distributions of the coherent monosynaptic activity in layer IV and of the two prominent polysynaptic activities in layers III and II. The widely scattered activity in the lower part of layer IV in A 17 and all infragranular activities in both areas generate smaller, partly closed-field potentials; those are not discernible from the strong far-field potentials which originate from the supragranular activity and — especially in A 17 —from farther distant events.

     

Key words

Visual cortex Current source density analysis Field potentials Cat 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Cleland, B.G., Dubin, M.W., Levick, W.R.: Sustained and transient neurons in the cat's retina and lateral geniculate nucleus. J Physiol (Lond) 217, 473–496 (1971)Google Scholar
  2. Creutzfeldt, O.D., Garey, L.J., Kuroda, R., Wolff, J.-R.: The distribution of degenerating axons after small lesions in the intact and isolated visual cortex of the cat. Exp Brain Res 27, 419–440 (1977)Google Scholar
  3. Creutzfeldt, O.D., Houchin, J.: Neuronal basis of EEG-waves. In: A. Rémond (Ed.): Handbook of Electroencephalography and Clinical Neurophysiology, Vol. 2, Part C (Ed.: O. Creutzfeldt) Amsterdam: Elsevier 1974Google Scholar
  4. Creutzfeldt, O.D., Kuhnt, U.: Electrophysiology and topographical distribution of visual evoked potentials in animals. In: Handbook of Sensory Physiology. Vol. VII, 3B. (Ed.: R. Jung), pp. 595–646. Berlin, Heidelberg, New York: Springer 1973Google Scholar
  5. Freeman, J.A., Nicholson, C.: Experimental optimization of current source-density technique for Anuran cerebellum. J Neurophysiol 38, 369–382 (1975)Google Scholar
  6. Freeman, J.A., Stone, J.: A technique for current density analysis of field potentials and its application to the frog cerebellum. In: Neurobiology of Cerebellar Evolution and Development. (Ed. R. Llinás), pp. 421–430. Chicago: American Medical Association 1969Google Scholar
  7. Garey, L.J., Powell, T.P.S.: The projection of the lateral geniculate nucleus upon the cortex in the cat. Proc R Soc Lond [Biol] 169, 107–126 (1967)Google Scholar
  8. Gilbert, C.D.: Laminar differences in receptive field properties of cells in cat primary visual cortex. J Physiol (Lond) 268, 391–421 (1977)Google Scholar
  9. Gilbert, C.D., Kelly, J.P.: The projections of cells in different layers of the cat's visual cortex. J Comp Neurol 163, 81–106 (1975)Google Scholar
  10. Hoffmann, K.-P., Stone, J.: Conduction velocity of afferents to cat visual cortex: a correlation with cortical receptive field properties. Brain Res 32, 460–466 (1971)Google Scholar
  11. Holländer, H., Vanegas, H.: The projection from the lateral geniculate nucleus onto the visual cortex in the cat. A quantitative study with horseradish-peroxidase. J Comp Neurol 173, 519–536 (1977)Google Scholar
  12. Hubel, D.H., Wiesel, T.N.: Laminar and columnar distribution of geniculo-cortical fibers in the macaque monkey. J Comp Neurol 146, 421–450 (1972)Google Scholar
  13. Humphrey, D.R.: Re-analysis of the antidromic cortical response. II. On the contribution of cell discharge and PSPs to the evoked potentials. Electroencephalogr Clin Neurophysiol 25, 421–442 (1968)Google Scholar
  14. LeVay, S., Ferster, D.: Relay cell classes in the lateral geniculate nucleus of the cat and the effect of visual deprivation. J Comp Neurol 172, 567–584 (1977)Google Scholar
  15. LeVay, S., Gilbert, C.D.: Laminar patterns of geniculo cortical projection in the cat. Brain Res 113, 1–19 (1976)Google Scholar
  16. Mitzdorf, U., Singer, W.: Laminar segregation of afferents to lateral geniculate nucleus of the cat: an analysis of current source density. J Neurophysiol 40, 1227–1244 (1977)Google Scholar
  17. Nicholson, C., Freeman, J.A.: Theory of current source-density analysis and determination of conductivity tensor for Anuran cerebellum. J Neurophysiol 38, 356–368 (1975)Google Scholar
  18. Otsuka, R., Hassler, R.: Über Aufbau und Gliederung der corticalen Sehsphäre bei der Katze. Arch Psychiat Nervenkr 203, 212–234 (1962)Google Scholar
  19. Palmer, L.A., Rosenquist, A.C.: Visual receptive fields of single striate cortical units projecting to the superior colliculus in the cat. Brain Res 67, 27–42 (1974)Google Scholar
  20. Plonsey, R.: Bioelectric Phenomena. New York: Me Graw-Hill 1969Google Scholar
  21. Rall, W.: Distinguishing theoretical synaptic potentials computed for different soma-dendritic distributions of synaptic input. J Neurophysiol 30, 1138–1168 (1967)Google Scholar
  22. Rosenquist, A.C., Edwards, S.B., Palmer, L.A.: An autoradiographic study of the projections of the dorsal lateral geniculate nucleus and the posterior nucleus in the cat. Brain Res 80, 71–93 (1974)Google Scholar
  23. Rossignol, S., Colonnier, M.: A light microscope study of degeneration patterns in cat cortex after lesions of the lateral geniculate nucleus. Vision Res Suppl 3, 329–338 (1971)Google Scholar
  24. Singer, W.: The effect of mesencephalic reticular stimulation on intracellular potentials of cat lateral geniculate neurons. Brain Res 61, 35–54 (1973)Google Scholar
  25. Singer, W.: The control of thalamic transmission by corticofugal and ascending reticular pathways in the visual system. Physiol Rev 57, 386–420 (1977)Google Scholar
  26. Singer, W., Tretter, F., Cynader M.: Organization of cat striate cortex: A correlation of receptive-field properties with afferent and efferent connections. J Neurophysiol 38, 1080–1096 (1975)Google Scholar
  27. Singer, W., Tretter, F., Cynader, M.: The effect of reticular stimulation on spontaneous and evoked activity in the cat visual cortex. Brain Res 102, 71–90 (1976)Google Scholar
  28. Stone, J., Dreher, B.: Projection of X- and Y-cells of the cat's lateral geniculate nucleus to areas 17 and 18 of visual cortex. J Neurophysiol 36, 551–567 (1973)Google Scholar
  29. Stone, J., Freeman, R.B., Jr.: Conduction velocity groups in the cat's optic nerve according to their retinal origin. Exp Brain Res 13, 489–497 (1971)Google Scholar
  30. Szentágothai, J.: Synaptology of the visual cortex. In: Handbook of Sensory Physiology. Vol. VII, 3B. (Ed.: R. Jung), pp. 269–324. Berlin, Heidelberg, New York: Springer 1973Google Scholar
  31. Toyama, K., Matsunami, K., Ohno, T., Tokashiki, S.: An intracellular study of neuronal organization in the visual cortex. Exp Brain Res 21, 45–66 (1974)Google Scholar
  32. Tretter, F., Cynader, M., Singer, W.: Cat parastriate cortex: A primary or secondary visual area? J Neurophysiol 38, 1099–1113 (1975)Google Scholar

Copyright information

© Springer-Verlag 1978

Authors and Affiliations

  • U. Mitzdorf
    • 1
  • W. Singer
    • 1
  1. 1.Max-PIanck-Institut für PsychiatrieMünchen 40Federal Republic of Germany

Personalised recommendations