Publication Date:
1989-09-01
Description:
In developing nervous systems, many peripheral and central pathways are established by early arising populations of pioneer neurons. The growth cones of these pioneer neurons can migrate while embryonic distances are short and while intervening tissue is relatively uncomplicated. Are these pioneers necessary? In grasshopper embryos, a pair of pioneer neurons arise at the tips of limb buds and extend axons through the limb to the central nervous system. Growth cones of later arising sensory neurons migrate along the pioneer axons. After ingrowth of sensory axons, the pioneer neurons die. If the pioneer neurons are prevented from differentiating by heat shock, then the sensory growth cones that would have migrated along them are blocked and fail to reach the central nervous system. Thus, the pioneer axons are necessary for successful migration of these sensory growth cones. By crossing a segment boundary early in embryogenesis, the pioneers circumvent an incompatibility between differentiated segment boundary cells and growth cone migration. Pioneer neurons may resolve similar problems in many systems.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Klose, M -- Bentley, D -- NS09074-20/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1989 Sep 1;245(4921):982-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular and Cell Biology, University of California, Berkeley 94720.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2772651" target="_blank"〉PubMed〈/a〉
Keywords:
Afferent Pathways/cytology/embryology
;
Animals
;
Embryo, Nonmammalian/physiology
;
Grasshoppers/*embryology
;
Hot Temperature
;
Neurons/*physiology
;
Peripheral Nerves/cytology/embryology
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
