Linked Life Data

8083731

Source:http://linkedlifedata.com/resource/pubmed/id/8083731

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
1994-10-12
pubmed:abstractText
NMDA receptor activation can alter synaptic strength, cause cell death, and may modulate the release of glutamate and other neurotransmitters. Using a specific and selective antiserum directed against the R1 subunit of the NMDA receptor, we examined (1) whether NMDA receptors in the adult rat visual cortex are exclusively postsynaptic or also presynaptic and (2) whether NMDA-R1 subunits are incorporated into the plasma membrane prior to, contemporaneously, or following the formation of synapses during postnatal development. By light microscopy, NMDA-R1 immunoreactivity in the adult visual cortex is easily detectable within perikarya and proximal dendrites in laminae 2-6. Many of them have the morphological features of pyramidal neurons. In addition, fine punctate labeling is evident throughout the neuropil. Electron microscopy reveals these puncta to reside at postsynaptic densities of axospinous junctions and at fine astrocytic processes and axon terminals. In the deeper laminae, the majority of labeled profiles are astrocytic. Visual cortices of animals in their first postnatal week show concentrated immunoreactivity in a few nonpyramidal neurons within laminae that have just differentiated from the cortical plate. Electron microscopy reveals diffuse labeling along the plasma membrane of dendritic shafts lacking morphologically identifiable synaptic junctions or appositions to axons. Immunoreactivity is detectable in dendritic processes by postnatal day (PND) 2, in axonal processes by PND 4, and in astrocytic profiles by PND 14. Immunoreactivity also is detectable along the postsynaptic membrane of presumably transient axosomatic junctions. At all ages, the prevalence of NMDA-R1-immunoreactive profiles is lamina 1 > 4/5 > 6/6B. These results provide the cellular basis for NMDA receptors' participation in (1) postsynaptic membrane excitability, (2) regulation of transmitter release, (3) and, in the deeper laminae, astrocyte responses. During development, NMDA-R1 subunits are associated with the plasma membrane prior to axons' arrival while clustering of receptors to junctions may be promoted by axonal contact. Finally, spatial segregation of axonal growth cones may be mediated by NMDA-R1 subunits on these axonal processes.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0270-6474
pubmed:author
pubmed:issnType
Print
pubmed:volume
14
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5202-22
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Cellular and subcellular localization of NMDA-R1 subunit immunoreactivity in the visual cortex of adult and neonatal rats.
pubmed:affiliation
Center for Neural Science, New York University, New York 10003.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't