Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2001-3-6
pubmed:abstractText
We have investigated the role of the NMDA glutamate receptor (NMDAR) in the genesis and regulation of structural plasticity during synaptogenesis in the visual layers of the rat superior colliculus (sSC). In this neuropil, three projections compete for synaptic space during development. By fluorescently labeling the projections of both eyes and imaging them with confocal microscopy, we can quantify the sprouting of the ipsilateral retinal projection that follows removal of a portion of the contralateral retinal and/or corticocollicular projection. Using these techniques we have studied the effects of NMDAR blockade under different levels of competition. NMDARs were chronically blocked from birth [postnatal day 0 (P0)] by suspending the competitive antagonist 2-amino-5-phosphonopentanoic acid in the slow release plastic Elvax, a slab of which was implanted over the sSC. Such treatment alone does not impair the normal segregation of the retinal projections. However, if sprouting of the ipsilateral projection is initiated with a small contralateral retinal lesion at P6, this sprouting can be further increased by blocking NMDARs from birth. Sprouting of the ipsilateral retinal projection is also induced by retinal lesions made at P10/P11, but NMDAR blockade does not augment the sprouting induced by this later lesion. However, when combined with simultaneous ablation of the ipsilateral visual cortex, P10/P11 lesions show increased sprouting after NMDAR blockade. These data indicate that P0 NMDAR blockade does not eliminate synaptic competition in the sSC. Instead, early elimination of NMDAR function appears to facilitate sprouting that is gated in a stepwise manner by the other visual afferents.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1529-2401
pubmed:author
pubmed:issnType
Electronic
pubmed:day
1
pubmed:volume
21
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1557-68
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:11222646-2-Amino-5-phosphonovalerate, pubmed-meshheading:11222646-Animals, pubmed-meshheading:11222646-Animals, Newborn, pubmed-meshheading:11222646-Axons, pubmed-meshheading:11222646-Cell Count, pubmed-meshheading:11222646-Cerebral Decortication, pubmed-meshheading:11222646-Drug Implants, pubmed-meshheading:11222646-Excitatory Amino Acid Antagonists, pubmed-meshheading:11222646-Fluorescent Dyes, pubmed-meshheading:11222646-Neuronal Plasticity, pubmed-meshheading:11222646-Occipital Lobe, pubmed-meshheading:11222646-Rats, pubmed-meshheading:11222646-Rats, Sprague-Dawley, pubmed-meshheading:11222646-Receptors, N-Methyl-D-Aspartate, pubmed-meshheading:11222646-Retina, pubmed-meshheading:11222646-Retinal Ganglion Cells, pubmed-meshheading:11222646-Scotoma, pubmed-meshheading:11222646-Superior Colliculi, pubmed-meshheading:11222646-Visual Pathways
pubmed:year
2001
pubmed:articleTitle
Chronic NMDA receptor blockade from birth increases the sprouting capacity of ipsilateral retinocollicular axons without disrupting their early segregation.
pubmed:affiliation
Interdepartmental Neuroscience Program, Yale University, New Haven, Connecticut 06520, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.