Tenascin and laminin function in target recognition and central synaptic differentiation.
The influence of the target cell-issued extracellular molecules tenascin-C and laminin on synaptogenesis was studied in mixed primary cultures of pituitary melanotrophs and hypothalamic neurons. We could demonstrate in this neuron-target co-culture system a new role for tenascin-C, which appeared to be expressed as an early and transitory signal of target recognition for selective afferent fibers. Tenascin-C expression disappeared from the melanotrophs soon after the establishment of neural contacts. Concomitantly, the melanotrophs became immunoreactive for laminins, and more specifically for the synaptic isoform beta2 chain-containing laminin. The laminin signal appeared to be involved in the induction of synaptic differentiation, selectively with fibers containing both dopamine and GABA, like those innervating the melanotrophs in situ.
Soussand
J
J
CNRS/ULP UMR 7519, IPCB, Strasbourg, France.
Jahké
R
R
Simon-Assmann
P
P
Stoeckel
M E
ME
Schimchowitsch
S
S
D000344:Afferent Pathways / Q000166:cytology / Q000254:growth & development / Q000502:physiology; D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D018920:Coculture Techniques; D005455:Fluorescent Antibody Technique; D007150:Immunohistochemistry; D007797:Laminin / Q000502:physiology*; D018613:Microscopy, Confocal; D010902:Pituitary Gland / Q000166:cytology / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013569:Synapses / Q000502:physiology*; D019063:Tenascin / Q000502:physiology*
D007797:Laminin; D019063:Tenascin