Linked Life Data

17289278

Source:http://linkedlifedata.com/resource/pubmed/id/17289278

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2007-3-12
pubmed:abstractText
The vertebrate neuromuscular junction (NMJ) is known to be a cholinergic synapse at which acetylcholine (ACh) is released from the presynaptic terminal to act on postsynaptic nicotinic ACh receptors. There is now growing evidence that glutamate, which is the main excitatory transmitter in the CNS and at invertebrate NMJs, may have a signaling function together with ACh also at the vertebrate NMJ. In the CNS, the extracellular concentration of glutamate is kept at a subtoxic level by Na(+)-driven high-affinity glutamate transporters located in plasma membranes of astrocytes and neurons. The glutamate transporters are also pivotal for shaping glutamate receptor responses at synapses. In order to throw further light on the potential role of glutamate as a cotransmitter at the NMJ we used high-resolution immunocytochemical methods to investigate the localization of the plasma membrane glutamate transporters GLAST (glutamate aspartate transporter) and GLT (glutamate transporter 1) in rat and mice NMJ regions. Confocal laser-scanning immunocytochemistry showed that GLT is restricted to the NMJ in rat and mouse skeletal muscle. Lack of labeling signal in knock-out mice confirmed that the immunoreactivity observed at the NMJ was specific for GLT. GLAST was also localized at the NMJ in rat but not detected in mouse NMJ (while abundant in mouse brain). Post-embedding electron microscopic immunocytochemistry and quantitative analyses in rat showed that GLAST and GLT are enriched in the junctional folds of the postsynaptic membrane at the NMJ. GLT was relatively higher in the slow-twitch muscle soleus than in the fast-twitch muscle extensor digitorum longus, whereas GLAST was relatively higher in extensor digitorum longus than in soleus. The findings show--together with previous demonstration of vesicular glutamate, a vesicular glutamate transporter and glutamate receptors--that mammalian NMJs contain the machinery required for synaptic release and action of glutamate. This indicates a signaling role for glutamate at the normal NMJ and provides a basis for the ability of denervated muscle to be reinnervated by glutamatergic axons from the CNS.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0306-4522
pubmed:author
pubmed:issnType
Print
pubmed:day
16
pubmed:volume
145
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
579-91
pubmed:meshHeading
pubmed-meshheading:17289278-Animals, pubmed-meshheading:17289278-Excitatory Amino Acid Transporter 1, pubmed-meshheading:17289278-Excitatory Amino Acid Transporter 2, pubmed-meshheading:17289278-Glutamic Acid, pubmed-meshheading:17289278-Immunohistochemistry, pubmed-meshheading:17289278-Male, pubmed-meshheading:17289278-Mice, pubmed-meshheading:17289278-Mice, Inbred C57BL, pubmed-meshheading:17289278-Mice, Knockout, pubmed-meshheading:17289278-Microscopy, Confocal, pubmed-meshheading:17289278-Microscopy, Immunoelectron, pubmed-meshheading:17289278-Motor Neurons, pubmed-meshheading:17289278-Muscle, Skeletal, pubmed-meshheading:17289278-Muscle Fibers, Fast-Twitch, pubmed-meshheading:17289278-Muscle Fibers, Slow-Twitch, pubmed-meshheading:17289278-Neuromuscular Junction, pubmed-meshheading:17289278-Rats, pubmed-meshheading:17289278-Rats, Wistar, pubmed-meshheading:17289278-Signal Transduction, pubmed-meshheading:17289278-Species Specificity, pubmed-meshheading:17289278-Synaptic Membranes, pubmed-meshheading:17289278-Synaptic Transmission
pubmed:year
2007
pubmed:articleTitle
Subcellular localization of the glutamate transporters GLAST and GLT at the neuromuscular junction in rodents.
pubmed:affiliation
Department of Anatomy and Centre for Molecular Biology and Neuroscience, University of Oslo, P.O. Box 1105 Blindern, N0317 Oslo, Norway.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't