Unidirectional photoreceptor-to-Müller glia coupling and unique K+ channel expression in Caiman retina

Autor: Alexei Verkhratsky, Anett Karl, Alexey Savvinov, Jose Davila, Luis A. Cubano, Mikhail Inyushin, Andreas Reichenbach, Astrid Zayas-Santiago, Elke Ulbricht, Silke Agte, Yuriy V. Kucheryavykh, Yomarie Rivera, Mike Francke, Misty J. Eaton, Thomas Pannicke, Serguei N. Skatchkov, Jan Benedikt, Rüdiger W. Veh
Jazyk: angličtina
Rok vydání: 2014
Předmět:
Visual System
Physiology
lcsh:Medicine
Mechanical Treatment of Specimens
Membrane Potentials
0302 clinical medicine
Glutamates
Comparative Anatomy
lcsh:Science
Membrane potential
Neurons
0303 health sciences
Alligators and Crocodiles
Multidisciplinary
Inward-rectifier potassium ion channel
Glutamate receptor
Anatomy
Potassium channel
Sensory Systems
Cell biology
Electrophysiology
medicine.anatomical_structure
Electroporation
Specimen Disruption
Muller glia
Ion Channel Gating
Ependymoglial Cells
Research Article
Photoreceptor Cells
Vertebrate
Signal Transduction
Cell Physiology
Nerve Tissue Proteins
Biology
Research and Analysis Methods
Retina
03 medical and health sciences
Potassium Channels
Tandem Pore Domain
medicine
Animals
Potassium Channels
Inwardly Rectifying
030304 developmental biology
Fluorescent Dyes
lcsh:R
Biology and Life Sciences
Cell Biology
Protein Structure
Tertiary
Specimen Preparation and Treatment
Cellular Neuroscience
Potassium
lcsh:Q
sense organs
030217 neurology & neurosurgery
Neuroscience
Zdroj: PLoS ONE, Vol 9, Iss 5, p e97155 (2014)
PLoS ONE
ISSN: 1932-6203
Popis: BACKGROUND: Muller cells, the principal glial cells of the vertebrate retina, are fundamental for the maintenance and function of neuronal cells. In most vertebrates, including humans, Muller cells abundantly express Kir4.1 inwardly rectifying potassium channels responsible for hyperpolarized membrane potential and for various vital functions such as potassium buffering and glutamate clearance; inter-species differences in Kir4.1 expression were, however, observed. Localization and function of potassium channels in Muller cells from the retina of crocodiles remain, hitherto, unknown. METHODS: We studied retinae of the Spectacled caiman (Caiman crocodilus fuscus), endowed with both diurnal and nocturnal vision, by (i) immunohistochemistry, (ii) whole-cell voltage-clamp, and (iii) fluorescent dye tracing to investigate K+ channel distribution and glia-to-neuron communications. RESULTS: Immunohistochemistry revealed that caiman Muller cells, similarly to other vertebrates, express vimentin, GFAP, S100beta, and glutamine synthetase. In contrast, Kir4.1 channel protein was not found in Muller cells but was localized in photoreceptor cells. Instead, 2P-domain TASK-1 channels were expressed in Muller cells. Electrophysiological properties of enzymatically dissociated Muller cells without photoreceptors and isolated Muller cells with adhering photoreceptors were significantly different. This suggests ion coupling between Muller cells and photoreceptors in the caiman retina. Sulforhodamine-B injected into cones permeated to adhering Muller cells thus revealing a uni-directional dye coupling. CONCLUSION: Our data indicate that caiman Muller glial cells are unique among vertebrates studied so far by predominantly expressing TASK-1 rather than Kir4.1 K+ channels and by bi-directional ion and uni-directional dye coupling to photoreceptor cells. This coupling may play an important role in specific glia-neuron signaling pathways and in a new type of K+ buffering.
Databáze: OpenAIRE
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