Modulatory Effects of Perineuronal Oligodendrocytes on Neuronal Activity in the Rat Hippocampus
| Autor: | Yasukazu Hozumi, Kenya Kaneko, Yoshihiko Yamazaki, Satoshi Fujii |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Potassium Channels Interneuron Action Potentials Biology Biochemistry Hippocampus Membrane Potentials Rats Sprague-Dawley 03 medical and health sciences Cellular and Molecular Neuroscience chemistry.chemical_compound 0302 clinical medicine Interneurons Biological neural network medicine Premovement neuronal activity Animals Neurons Tetraethylammonium musculoskeletal neural and ocular physiology Pyramidal Cells Afterhyperpolarization Depolarization General Medicine Hyperpolarization (biology) Oligodendrocyte Oligodendroglia 030104 developmental biology medicine.anatomical_structure nervous system chemistry Neuroscience 030217 neurology & neurosurgery |
| Zdroj: | Neurochemical research. 43(1) |
| ISSN: | 1573-6903 |
| Popis: | Action potentials are fundamental to relaying information from region to region in the nervous system. Changes in action potential firing patterns in neural circuits influence how the brain processes information. In our previous study, we focused on interneuron/perineuronal astrocyte pairs in the hippocampal CA1 region and reported that direct depolarization of perineuronal astrocytes modulated the firing pattern of interneurons. In the current study, we investigated the morphological and electrophysiological properties of perineuronal oligodendrocytes, and examined their modulatory effects on interneuronal firing in the CA1 region. Perineuronal oligodendrocytes only had a few processes, which were crooked, intricately twisted, and twined around the soma and proximal region of the main processes of adjacent interneurons. Whole-cell current patterns of perineuronal oligodendrocytes were homogenous and the current-voltage relationship showed remarkable outward rectification. Although the K+ channel blockers, tetraethylammonium and 4-aminopyridine, clearly blocked outward currents, Ba2+ did not significantly alter whole-cell currents. Unlike perineuronal astrocytes, the depolarization of perineuronal oligodendrocytes had no effect on interneuronal firing; however, when the interneurons were firing at a higher frequency, the hyperpolarization of perineuronal oligodendrocytes suppressed their action potentials. The suppressive effects of perineuronal oligodendrocytes were inhibited in the presence of a low concentration of tetraethylammonium, which selectively blocked deep and fast afterhyperpolarization. These results suggest that perineuronal oligodendrocytes suppress interneuronal firing through their influence on K+ channels, which are responsible for deep and fast afterhyperpolarization. |
| Databáze: | OpenAIRE |
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