AXONAL COLLATERAL-COLLATERAL TRANSPORT OF TRACT TRACERS IN BRAIN NEURONS - FALSE ANTEROGRADE LABELING AND USEFUL TOOL

Citation
S. Chen et G. Astonjones, AXONAL COLLATERAL-COLLATERAL TRANSPORT OF TRACT TRACERS IN BRAIN NEURONS - FALSE ANTEROGRADE LABELING AND USEFUL TOOL, Neuroscience, 82(4), 1998, pp. 1151-1163
Citations number
34
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Neurosciences
Journal title
ISSN journal
0306-4522
Volume
82
Issue
4
Year of publication
1998
Pages
1151 - 1163
Database
ISI
SICI code
0306-4522(1998)82:4<1151:ACTOTT>2.0.ZU;2-4
Abstract
It is well established that some neuroanatomical tracers may be taken up by local axonal terminals and transported to distant axonal collate rals (e.g., transganglionic transport in dorsal root ganglion cells). However, such collateral-collateral transport of tracers has not been systematically examined in the central nervous system. We addressed th is issue with four neuronal tracers-biocytin, biotinylated dextran ami ne, cholera toxin B subunit, and Phaseolus vulgaris-leucoagglutinin-in the cerebellar cortex. Labelling of distant axonal collaterals in the cerebellar cortex (indication of collateral-collateral transport) was seen after focal iontophoretic microinjections of each of the four tr acers. However, collateral-collateral transport properties differed am ong these tracers. Injection of biocytin or Phaseolus vulgaris-leucoag glutinin in the cerebellar cortex yielded distant collateral labelling only in parallel fibres. In contrast, injection of biotinylated dextr an amine or cholera toxin B subunit produced distant collateral labell ing of climbing fibres and messy fibres, as well as parallel fibres. T he present study is the first systematic examination of collateral-col lateral transport following injection of anterograde tracers in brain. Such collateral-collateral transport may produce false-positive concl usions regarding neural connections when using these tracers for anter ograde transport. However, this property may also be used as a tool to determine areas that are innervated by common distant afferents. In a ddition, these results may indicate a novel mode of chemical communica tion in the nervous system. (C) 1997 IBRO. Published by Elsevier Scien ce Ltd.