Publication Date:
1990-01-12
Description:
Individual neurons in the brain send their axons over considerable distances to multiple targets, but the mechanisms governing this process are unresolved. An amenable system for studying axon outgrowth, branching, and target selection is the mammalian corticopontine projection. This major connection develops from parent corticospinal axons that have already grown past the pons, by a delayed interstitial budding of collateral branches that then grow directly into their target, the basilar pons. When cocultured with explants of developing cortex in three-dimensional collagen matrices, the basilar pons elicits the formation and directional growth of cortical axon collaterals across the intervening matrix. This effect appears to be target-specific and selectively influences neurons in the appropriate cortical layer. These in vitro findings provide evidence that the basilar pons becomes innervated by controlling at a distance the budding and directed ingrowth of cortical axon collaterals through the release of a diffusible, chemotropic molecule.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Heffner, C D -- Lumsden, A G -- O'Leary, D D -- EY07025/EY/NEI NIH HHS/ -- New York, N.Y. -- Science. 1990 Jan 12;247(4939):217-20.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, MO 63110.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2294603" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Axons/*physiology/ultrastructure
;
Cerebral Cortex/growth & development/*ultrastructure
;
Culture Techniques
;
Fluorescent Dyes
;
Motor Cortex/ultrastructure
;
Nerve Growth Factors/physiology
;
Neural Pathways/growth & development/ultrastructure
;
Pons/*physiology/ultrastructure
;
Rats
;
Spinal Cord/ultrastructure
;
Visual Cortex/ultrastructure
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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