Origin of cells in contact with the growth cones of embryonal peripheral nerves and histochemical detection of nonspecific cholinesterase activity in quail‐chick and chick‐quail chimeras

Abstract

The types of cells contacted by growth cones were examined in chick-quail and vice versa chimeras. Simultaneously, the presence of nonspecific cholinesterase (nChE) was monitored in developing peripheral nerves of these embryos. In all the chimeras studied, the growth cones were in contact with both Schwann cell progenitors and mesenchymal cells of the limb bud. This observation implies that the growth cones may obtained guidance cues directly from the mesenchymal cells of the limb bud. Schwann cell progenitors as well as mesenchymal cells in contact with growth cones were capable to produce nChE molecules. The reaction product indicating nChE activity was localized on the outer surface of the plasma membrane of both types of cells in contact with growth cones. However, mesenchymal cells forming the "primitive perineurium" were devoid of the reaction product on their plasma membrane. We conclude that with exception of classic adhesive molecules the process of axonal guidance can be mediated by nChE molecules.

Χρήση βιοσημάντων των βιοδεικτών coturnix coturnix japonica ( ορτύκι) και onchorhynchus mykiss (πέστροφα) για την αξιολόγηση οικοτοξικολογικών επιπτώσεων του methamidophos

“…ηδκ πναβιαηζηυηδηα, ζε μνζζιέκεξ πενζπηχζεζξ δ ζζημπδιζηή πνχζδ βζα ηδκ BuChE θάκδηε κα ακήηεζ ζε κεονμβθμζαηά ηφηηανα, πμο ακαβκςνίγμκηαζ απυ ημ ιέβεεμξ ηαζ ηδ εέζδ ημοξ, ηαζ ζοιθςκεί ιε πνμδβμφιεκεξ δδιμζζεφζεζξ ζε εβηέθαθμ πηδκχκ, εδθαζηζηχκ, ζοιπενζθαιαακμιέκμο ημο ακενχπζκμο (Dubovy, 1991;Haninec and Dubovy, 1992;Wright 1993a, b;Mesulam et al 2002) (Chattonnet ηαζ Lockridge, 1989;Massoulié et al 1999). ε γχα πμο εηηέεδηακ ζε έκα πανειπμδζζηή ηδξ AChE, ημ diisopropylphosphorofluoridate (Meneguz et al 1989), ημ chlorpyrifos (Ricceri et al 2003), ή ημ soman (Lintern et al 1998) (Afifi et al 1991;Sharma et al 2005;Gokcimen et al 2007;Yehia et al 2007;Sayim, 2007).…”