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Virchows Archiv B

, 6:1 | Cite as

Ultrastructural studies on the long term effects of sodium glutamate on the rat retina

  • H. -A. Hansson
Article
  • 18 Downloads

Summary

Suckling rats were treated with sublethal doses of monosodium-L-glutamate for from one day up to two weeks. The retinae and the optic nerves and tracts were examined after two to ten months by transmission electron microscopy.

The nerve cells in the ganglion cell layer and in the inner nuclear layer were destroyed with few exceptions. The occasionally remaining neurons were small and immature. The rest of the cells in the inner part of the glutamate-damaged retinae consisted of Müllerian neuroglial cells, astrocytes and occasionally observed oligodendrocytes. Scattered glial cells of an intermediate type, perhaps representing microglial cells or reactive neuroglial cells, were also observed. There were many extracellular spaces of varying size and shape among the glial cells. The neuroglial processes formed helical structures. There was a reduction in the number of synaptic bodies and a relative increase in the somatic type of rod cell synapses. The photoreceptor cells and the epithelial cells appeared otherwise unchanged.

The number of myelinated axons was reduced to about one per cent of the normal in the optic nerve and tract. Desmosomes were frequent between astrocytic processes.

The results are discussed in relation to those obtained in previous studies on retinal damage induced by glutamate.

Keywords

Glutamate Optic Nerve Nerve Cell Photoreceptor Cell Ganglion Cell Layer 
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.

Zusammenfassung

Babyratten wurden mit einer sublethalen Dosis monosodium-L-glutamat (1 Tag bis zu 2 Wochen) behandelt. Die Netzhäute und Sehnerven samt Umgebung wurden nach 2–10 Monaten elektronenmikroskopisch untersucht.

Die Nervenzellen in der Ganglienzellschicht und der inneren Körnerschicht waren mit einigen Ausnahmen zerstört. Die zufällig übriggebliebenen Neuronen waren klein und unreif. Die Zellreste im inneren Abschnitt der. glutamatgeschädigten Netzhäute bestehen aus den Müllerschen neuroglialen Zellen, Astrocyten und zufällig beobachteten Oligodendrocyten. Auch zerstreute gliale Zellen eines dazwischenliegenden Typs, die vielleicht mikrogliale Zellen oder aktive neurogliale Zellen darstellen, wurden beobachtet. Zwischen den glialen Zellen fanden sich viele extracellulare Räume von wechselnder Größe und Form. Die neuroglialen Fortsätze bildeten schneckenartige Strukturen. Die Anzahl der synaptischen Körperchen war reduziert, der somatische Typ der Stabzellensynapsen hatte zugenommen. Die Photoreceptor- und Epithelzellen erschienen unverändert.

Die Anzahl der myelinisierten Axone in Sehnerven und Umgebung war auf ungefähr 1 % der Norm reduziert. Desmosomen zwischen den astrocytischen Prozessen waren häufig zu sehen.

Die Ergebnisse werden mit denen vorangegangener Studien von glutamatbedingten Netzhautzerstörungen verglichen.

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Copyright information

© Springer-Verlag 1970

Authors and Affiliations

  • H. -A. Hansson
    • 1
  1. 1.Department of Histology and the Neuropathological Laboratory, Department of Pathology IUniversity of GöteborgGöteborgSweden

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