Linked Life Data

2307281

Source:http://linkedlifedata.com/resource/pubmed/id/2307281

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1990-4-12
pubmed:abstractText
In previous work using neural transplants (Hankin and Lund, 1987) we demonstrated two basic components of optic axon outgrowth in the mammalian retinotectal system: one category of outgrowth utilizes the subpial margin of the rostral brain stem as a preferential substrate (as do normal retinotectal axons); the other type of outgrowth, from retinae embedded deep within the midbrain parenchyma, is distance-dependent and highly target-oriented, but shows little apparent substrate specificity. One explanation for this directed outgrowth is that it is in response to a diffusible factor emanating from cells in the superior colliculus. In the present study we use congenitally anophthalmic mice as recipients for retinal transplants to test whether prior optic innervation of the superior colliculus plays a role in establishing either component of outgrowth. We show that outgrowth along the subpial pathway from a graft placed on the surface of the brain stem can take place in the absence of prior innervation of the superior colliculus. The target-directed outgrowth exhibited by embedded grafts only occurs if the tectum is also innervated by a second graft placed on the surface of the brain stem. It is proposed that tectal cells produce a factor in response to optic innervation and that this directs the growth patterns of embedded grafts. This suggests that optic innervation is a necessary prerequisite for the superior colliculus to produce the proposed diffusible chemotropic signal. In normal development such a factor could function to improve the efficiency of target-finding by later growing optic axons, but it might serve a quite different role, encouraging branching and trophic maintenance of the optic pathway once it has reached the tectum.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0012-1606
pubmed:author
pubmed:issnType
Print
pubmed:volume
138
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
136-46
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Induction of target-directed optic axon outgrowth: effect of retinae transplanted to anophthalmic mice.
pubmed:affiliation
Department of Neurobiology, Anatomy and Cell Science, School of Medicine, University of Pittsburgh, Pennsylvania 15261.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.