Edwards, IJ, Bruce, G, Lawrenson, C et al. (4 more authors) (2013) Na+/K+ ATPase α1 and α3 Isoforms Are Differentially Expressed in α- and γ-Motoneurons. Journal of Neuroscience, 33 (24). 9913 - 9919. ISSN 0270-6474
Abstract
The Na(+)/K(+) ATPase (NKA) is an essential membrane protein underlying the membrane potential in excitable cells. Transmembrane ion transport is performed by the catalytic α subunits (α1-4). The predominant subunits in neurons are α1 and α3, which have different affinities for Na(+) and K(+), impacting on transport kinetics. The exchange rate of Na(+)/K(+) markedly influences the activity of the neurons expressing them. We have investigated the distribution and function of the main isoforms of the α subunit expressed in the mouse spinal cord. NKAα1 immunoreactivity (IR) displayed restricted labeling, mainly confined to large ventral horn neurons and ependymal cells. NKAα3 IR was more widespread in the spinal cord, again being observed in large ventral horn neurons, but also in smaller interneurons throughout the dorsal and ventral horns. Within the ventral horn, the α1 and α3 isoforms were mutually exclusive, with the α3 isoform in smaller neurons displaying markers of γ-motoneurons and α1 in α-motoneurons. The α3 isoform was also observed within muscle spindle afferent neurons in dorsal root ganglia with a higher proportion at cervical versus lumbar regions. We confirmed the differential expression of α subunits in motoneurons electrophysiologically in neonatal slices of mouse spinal cord. γ-Motoneurons were excited by bath application of low concentrations of ouabain that selectively inhibit NKAα3 while α-motoneurons were insensitive to these low concentrations. The selective expression of NKAα3 in γ-motoneurons and muscle spindle afferents, which may affect excitability of these neurons, has implications in motor control and disease states associated with NKAα3 dysfunction.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) 2013, Society for Neuroscience. Reproduced in accordance with the publisher's self-archiving policy. |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Biological Sciences (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 04 Jul 2013 10:28 |
Last Modified: | 15 Sep 2014 03:20 |
Published Version: | http://dx.doi.org/10.1523/JNEUROSCI.5584-12.2013 |
Status: | Published |
Publisher: | Society for Neuroscience |
Identification Number: | 10.1523/JNEUROSCI.5584-12.2013 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:75872 |