Distribution of laminin and fibronectin along peripheral trigeminal axon pathways in the developing chick

Abstract

The trigeminal region of the chick was studied with indirect immunofluorescence in order to determine whether extracellular matrix components might be distributed in such a way as to guide trigeminal axons to their peripheral targets in the mandibular arch. Tissue sections from stages 13-15 and 21/22 were immunolabeled indirectly with affinity-purified antibodies raised against fibronectin and laminin, two extracellular matrix glycoproteins that support axon growth in vitro. Fibronectin was distributed ubiquitously throughout the head mesenchyme prior to and during initial axon growth from the brainstem (stages 13-15). Shortly after trigeminal axons reached their target tissues (stage 21/22), fibronectin immunolabeling was distributed throughout the head mesenchyme, but was present only at low levels in the trigeminal ganglion and motor nerve. Laminin immunolabeling was distributed in the lateral head mesenchyme at stage 13 as small specks and patches. At stage 14, when the motor axons first exit from the brainstem, short, linear arrays of laminin immunostaining were present from the basement membrane of the neural tube to the core of the mandibular arch, and many were parallel to the direction of axon growth. By stage 21/22 the trigeminal ganglion and motor root showed intense antilaminin immunofluorescence as did the central core of the mandibular arch. These studies suggest that the distribution of fibronectin within the head mesenchyme cannot give directional information to the growing trigeminal axons because of its homogeneous distribution. However, the initial distribution of laminin during the earliest stages of axon outgrowth may provide an extracellular matrix pathway that permits trigeminal axons to reach their targets.

Filopodia initiate choices made by sensory neuron growth cones at laminin/fibronectin borders in vitro

“…Consistent with this proposal is the immunohistochemical localization of both growth-promoting and growth-inhibiting macromolecules along many neuronal migratory routes Rogers et al, 1986;Riggott and Moody, 1987;Harris, 1989;Snow et al, 1990b). Further evidence for local regulation of growth cone behavior along neuronal pathways is the presence of "decision points" where growth cones make stereotyped choices among several alternative routes (Tosney and Landmesser, 1985b;Caudy and Bentley, 1986;Bovolenta and Mason, 1987;Sretavan and Reichardt, 1993).…”

The influence of fibronectin and laminin during Schwann cell migration and peripheral nerve regeneration through silicon chambers

“…Factors that increase cell adhesion favour rapid neurite initiation and growth by stabilizing the motile growth cone against retraction (Letourneau, 1975). Fibronectin mediates some of the interactions of the trigeminal growth cone surface with molecules in the surrounding extracellular matrix (Riggott & Moody, 1986). Fibronectin promotes neuritic outgrowth by influencing the organisation and/or assembly of cytoskeletal elements within the growing neurite tip (Akers et al, 1981).…”

Neurite Penetration into Collagen Gels Requires Ca²⁺-Dependent Metalloproteinase Activity

“…In some cases, it appears that axons grow along selected fascicules of other axons [Goodman et al, 1984;Kuwada, 1986;Landmesser and Honig, 1986], whereas in some cases axons seem to grow either autonomously or along pathways rich in specific extracellular matrix components such as laminin [Tosney and Landmesser, 1984;Silver and Rutishauser, 1984;Cohen et al, 1986;Rogers et al, 1986;Riggott and Moody, 1987]. Irrespective of the cues that determine axon guidance, it is clear that neurites in the peripheral nervous system grow within a 3-dimensional environ ment rich in extracellular matrix.…”