Nature Neuroscience
- 9, 1274 - 1283 (2006)
Published online: 3 September 2006; | doi:10.1038/nn1762
Focal adhesion kinase signaling at sites of integrin-mediated adhesion controls axon pathfinding
Estuardo Robles & Timothy M Gomez
Figure 4.FAK activity is required for point contact formation and stabilization of lamellipodial protrusions. (a,b) F-actin staining in wild-type growth cones on laminin and tenascin. (c) GFP-FRNK–expressing growth cone on laminin. (d–f) Paxillin immunofluorescence of regions indicated by red boxes in a–c. Punctate paxillin enrichments indicated by red arrows. (g–i) Paxillin immunofluorescence images in d–f subjected to exclusive thresholding to identify point contacts (yellow line indicates growth cone boundary). (j–l) Quantitative analysis of reduced FAK activity on the percentage of growth cones with paxillin puncta, number of puncta per growth cone and size of paxillin puncta. Quantification was restricted to the growth cone periphery. n > 40 growth cones in three cultures for each condition. (m–p) Fluorescence images of GFP-expressing control (m) and FAKmo-loaded (o) growth cones on laminin. Corresponding kymographs constructed from regions indicated by red lines. (q,r) Duration and size of lamellipodial extensions and retractions in control and FAK-inhibited growth cones. n > 12 growth cones for each condition. Scale bars: 5 m in a–c; 3.5 m in d–i; 7 m in m,o. Data are mean s.e.m. *P < 0.05, **P < 0.001. LN, laminin; FMO, FAKmo; TN, tenascin.
m in a–c; 3.5 
s.e.m. *
P < 0.05, **
P < 0.001. LN, laminin; FMO, FAKmo; TN, tenascin.
