Experimental Brain Research

, Volume 6, Issue 4, pp 324–352 | Cite as

Functional synaptic organization of primary visual cortex neurones in the cat

  • O. Creutzfeldt
  • M. Ito
Article

Summary

The spontaneous and light evoked post-synaptic activity of cells of the primary visual cortex was investigated with intracellular and quasi-intracellular records. The resting membrane potential fluctuated mostly between 3–10 mV below the firing threshold owing to spontaneous EPSP- and IPSP-activity. Discharge activity was therefore low. Forms and amplitudes of the visible EPSP's showed a large variability, the frequency was 150–300/sec. Discrete IPSP's were between 0.5–3 mV and were less frequent than EPSP's (about 1∶10). Their duration was only slightly longer than that of EPSP's. EPSP's and IPSP's could be elicited at on or off by appropriately positioned small light stimuli. During the initial reaction following a stimulus, single PSP's could be distinguished. Geniculate on-center- as well as off-center-afferents could lead to excitation or inhibition in different neurones. The receptive fields of cortical cells to monocular stimulation were analysed with averaged records. In each neurone 2–4 overlapping areas of on- or off-activation or -inhibition could be distinguished. Each of these activation or inhibition zones had the functional properties of a single geniculo-cortical onor off-center fibre with their receptive field centers separated by 1–3°. The variety of functional organizations of the cortical neurones to monocular stimulation was explained by variable combinations of 2–4 converging geniculate on- or off-center fibres with either excitatory or inhibitory action and variable overlap of their receptive fields. This was tested in a simple computer model. — Most neurones with pronounced reactions to movement or with direction specific movement sensitivity (about half of the neurones investigated) had an excitatory contact with an off-center fibre, which seemed to be mainly responsible for the movement reaction.- The findings suggest that from each eye less than 5 geniculo-cortical afferent converging fibres have a major effect on the activity of one cortical cell. Inhibitory afferents may be indirect and relayed through another cortical pyramidal cell.

Key Words

Visual cortex Intracellular recording Receptive fields Computer simulation 

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References

  1. Barlow, H.B., C. Blakemore and J.D. Pettigrew: The neural mechanism of binocular depth discrimination. J. Physiol. (Lond.) 193, 327–342 (1967).Google Scholar
  2. Baumgartner, G., u. P. Hakas: Neurophysiologie des simultanen Helligkeitskontrastes. Pflügers Arch. ges. Physiol. 274, 489–510 (1962).Google Scholar
  3. —: Visual motion detection in the cat. Science 146, 1070–1071 (1964).Google Scholar
  4. —: Responses of single units of the cat visual system to rectangular stimulus patterns. J. Neurophysiol. 28, 1–18 (1965).Google Scholar
  5. Burke, R.E.: Composite nature of the monosynaptic excitatory postsynaptic potential. J. Neurophysiol. 30, 1114–1137 (1967).Google Scholar
  6. Burns, B.O., W. Heron and R. Pitchard: Physiological excitation of visual cortex in cat's unanaesthetized isolated forebrain. J. Neurophysiol. 25, 165–181 (1962).Google Scholar
  7. Colonnier, M.: The structural design of the neo-cortex. In: Brain and Conscious Experience, pp. 1–23. Ed. by J.C. Eccles. Berlin-Heidelberg-New York: Springer 1966.Google Scholar
  8. Creutzfeldt, O., and M. Ito: Inhibition in the visual cortex. In: Inhibition in the nervous system, pp. 343–349. Ed. by K. v. Euler. Oxford and New York: Pergamon Press 1968.Google Scholar
  9. —, H.D. Lux and S. Watanabe: Electrophysiology of cortical nerve cells. In: The Thalamus, pp. 209–235. Ed. by D. Purpura and M.D. Yahr. New York and London: Columbia University Press 1966.Google Scholar
  10. Eccles, J.C.: The physiology of synapses. Berlin-Göttingen-Heidelberg: Springer 1964.Google Scholar
  11. Fuster, J.M., O.D. Creutzfeldt and M. Straschill: Intracellular recording of neuronal activity in the visual system. Z. vergl. Physiol. 49, 605–622 (1965).Google Scholar
  12. Globus, A., and A.B. Scheibel: Synaptic loci on visual cortical neurones. I. The specificafferent radiation. Exp. Neurol. 18, 116–131 (1967a).Google Scholar
  13. Herz, A., O. Creutzeeldt u. J.M. Fuster: Statistische Eigenschaften der Neuronenaktivität im ascendierenden visuellen System. Kybernetik 2, 61–71 (1964).Google Scholar
  14. Hubel, D.H.: Integrative processes in central visual pathways of the cat. J. Opt. Soc. America 53, 58–66 (1963).Google Scholar
  15. Hubel, D., and T.N. Wiesel: Receptive fields, binocular interaction and functional architecture in the cat's visual cortex. J. Physiol. (Lond.) 160, 106–154 (1962).Google Scholar
  16. — Shape and arrangement of columns in cat's striate cortex. J. Physiol. (Lond.) 165, 559–568 (1963).Google Scholar
  17. — Receptive fields and functional architecture in two non-striate visual areas (18 and 19) of the cat. J. Neurophysiol. 28, 229–289 (1965).Google Scholar
  18. Jung, R., R. v. Baumgarten u. G. Baumgartner: Mikroableitungen von einzelnen Nervenzellen im optischen Cortex: Die lichtaktivierten B-Neurone. Arch. Psychiat. Nervenkr. 189, 521–539 (1952).Google Scholar
  19. — Neuronal integration in the visual cortex and its significance for visual information. In: Sensory communication, pp. 627–674. Ed. by W. Rosenblith. New York-London: Wiley & Sons and M.I.T. Press 1961.Google Scholar
  20. Leyhausen, P.: Das Verhalten der Katzen (Felidae). Handb. d. Zool. 10, (21) 1–34(1956).Google Scholar
  21. McILWAIN, J.T., and O.D. Creutzfeldt: Microelectrode study of synaptic excitation and inhibition in the lateral geniculate nucleus of the cat. J. Neurophysiol. 30, 1–21 (1967).Google Scholar
  22. Mountcastle, V.B.: Modality and topographic properties of single neurones of cat's somatic sensory cortex. J. Neurophysiol. 20, 408–434 (1957).Google Scholar
  23. O'leary, J.T., and G.H. Bishop: The optically excitable cortex of the rabbit. J. comp. Neurol. 68, 423–478 (1937).Google Scholar
  24. Otsuka, R., u. R. Hassler: Über Aufbau und Gliederung der corticalen Sehsphäre der Katze. Arch. Psychiat. Nervenkr. 203, 212–234 (1962).Google Scholar
  25. Rall, W.: Distinguishing theoretical synaptic potentials computed for different soma-dendritic distributions of synaptic input. J. Neurophysiol. 30, 1138–1168 (1967).Google Scholar
  26. Ramón y Cajal, S.: Studien über die Sehrinde der Katze. J. Psychol. Neurol. (Lpz.) 29, 161–181 (1923).Google Scholar
  27. Rodieck, R.W., J.D. Pettigrew, P.O. Bishop and T. Nikara: Residual eye movements in receptive field studies of paralysed cats. Vision Res. 7, 107–110 (1967).Google Scholar
  28. —, and J. Stone: Analysis of receptive fields of cat retinal ganglion cells. J. Neurophysiol. 28, 833–849 (1965).Google Scholar
  29. Sholl, D.A.: The organization of the visual cortex in the cat. J. Anat. 89, 33–46 (1955).Google Scholar
  30. Szentágothai, J.: The anatomy of complex integrative units in the nervous system. In: Results in neuroanatomy, neurochemistry, neuropharmacology and neurophysiology, pp. 9–45. Ed. by K. Lissak. Budapest: Akademiai Kiado 1967.Google Scholar
  31. Watanabe, S., M. Konishi and O. Creutzfeldt: Postsynaptic potentials in the cat's visual cortex following electrical stimulation of afferent pathways. Exp. Brain Res. 1, 272–283 (1966).Google Scholar

Copyright information

© Springer-Verlag 1968

Authors and Affiliations

  • O. Creutzfeldt
    • 1
  • M. Ito
    • 1
  1. 1.Abteilung für NeurophysiologieMax-Planck-Institut für PsychiatrieMünchenGermany

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