Skip to main content
Log in

Ultrastructural characteristics of layer III pyramidal neurons in the cat primary auditory cortex (Al)

  • Published:
Neurophysiology Aims and scope

Abstract

Electron microscope studies were made of retrogradely horseradish peroxidase-labeled pyramidal neurons forming transcallosal projections in layer III of the cat primary auditory cortex (Al). These showed a significant proportion of the somatic membrane to be covered with processes of astroglia, while synapses occupy 20% of the synaptic surface on average. Between 4 and 10 axosomatic synapses were identified on the profiles of callosal cell somata. All these were formed by axonal terminals containing small, flattened synaptic vesicles and had symmetrical contacts. Average length of these synaptic contacts equaled 1.6 µm. Numerous anterogradely horseradish peroxidase-labeled axonal terminals of callosal fibers were found in cortical area Al in amongst retrogradely HP-labeled neurons. The ultrastructural pattern of these is described.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

Literature cited

  1. A. S. Batuev, and B. P. Babmindra, "Systemic principles underlying the organization of neurons producing cortical inhibition," Fiziol. Zh.,35, No. 3, 84–91 (1989).

    PubMed  Google Scholar 

  2. Yu. A. Gonchar and V. I. Kravets, "Electron microscope research into neurons of the cat primary auditory cortex (area Al) projecting to the medial geniculate body," Neirofiziologiya,22, No. 2, 171–178 (1990).

    Google Scholar 

  3. Yu. A. Gonchar and V. A. Maiskii, "Qualitative and quantitative characteristics of callosal neurons of the primary auditory cortex (area Al) in cats," Neirofiziologiya,22, No. 2, 249–257 (1990).

    Google Scholar 

  4. F. N. Serkov, Electrophysiology of the Higher Regions of the Auditory System [in Russian], Nauk. Dumka, Kiev (1977).

    Google Scholar 

  5. F. N. Serkov, Cortical Inhibition [in Russian], Nauk. Dumka, Kiev (1986).

    Google Scholar 

  6. V. L. Ezrokhi, I. V. Volkov, L. S. Grechushnikova, and L. Yu. Tarasova, "Monosynaptic connections between callosal system neurons and specific thalamic nuclei," Neirofiziologiya,17, No. 3, 305–314 (1985).

    Google Scholar 

  7. V. L. Ezrokhi, L. Yu. Tarasova, and L. I. Aleksandrov, "Callosal neurons: the monosynaptic connections between them and their descending projections," Zh. Vyssh. Nerv. Deyat.,35, No. 3, 528–536 (1985).

    Google Scholar 

  8. R. A. Code and J. A. Winer, "Commissural neurons in layer III of cat primary auditory cortex (Al): pyramidal and non-pyramidal cell input," J. Comp. Neurol.,242, No. 4, 485–510 (1985).

    PubMed  Google Scholar 

  9. T. J. Imig and J. F. Brugge, "Sources and terminations of callosal axons related to binaural and frequency maps in primary auditory cortex of the cat," J. Comp. Neurol.,182, No. 5, 637–660 (1978).

    PubMed  Google Scholar 

  10. T. J. Imig and R. A. Reale, "Ipsilateral cortico-cortical projections related to binaural columns in cat primary auditory cortex," J. Comp. Neurol.,203, No. 1, 1–14 (1981).

    PubMed  Google Scholar 

  11. J. P. Kelly and D. Wong, "Laminar connections of the cat's auditory cortex," Brain Res.,212, No. 1, 1–15 (1981).

    PubMed  Google Scholar 

  12. A. Mitani and M. Shimokouchi, "Neuronal connections in the primary auditory cortex: an electrophysiological study in the cat," J. Comp. Neurol.,235, No. 3, 417–429 (1985).

    PubMed  Google Scholar 

  13. A. Mitani, M. Shimokouchi, K. Itoh, et al., "Morphology and laminar organization of electrophysiologically identified neurons in the primary auditory cortex in the cat," J. Comp. Neurol.,235, No. 3, 430–447 (1985).

    PubMed  Google Scholar 

  14. A. Peters and E. G. Jones, "Classification of cortical neurons," in: Cerebral Cortex, Plenum Press, New York-London (1984), Vol. 1, pp. 107–121.

    Google Scholar 

  15. K. Schonitzer and H. Hollander, "Anterograde tracing of horseradish peroxidase (HRP) with the electron microscope using tetramethylbenzidine reaction," J. Neurosci. Meth.,4, No. 3, 373–383 (1981).

    Google Scholar 

  16. J. A. Winer, "The pyramidal neurons in layer III of the cat primary auditory cortex (Al)," J. Comp. Neurol.,229, No. 4, 476–496 (1984).

    PubMed  Google Scholar 

Download references

Authors

Additional information

A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 22, No. 4, pp. 520–526, July–August, 1990.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Gonchar, Y.A., Maiskii, V.A. Ultrastructural characteristics of layer III pyramidal neurons in the cat primary auditory cortex (Al). Neurophysiology 22, 389–395 (1990). https://doi.org/10.1007/BF01052481

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF01052481

Keywords

Navigation