|
|
|
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
|
Fig. 5. Rac1 is involved in agrin-induced growth-cone turning of Xenopus
neurons. (A) Agrin downregulates Rac1 activity in developing cerebellar
granule neurons. Western blots show the time course of activation of Rac1 and
Rho GTPase in cultured cerebellar granule cells following treatment with agrin
(100 ng/ml) for 1-30 minutes. Left, Rac1 activity; right, Rho activity. Total
Rac1 and Rho expression served as loading control (bottom panels). Results are
representative of at least three experiments and the fold change compared with
the untreated control is presented in the histograms. Each value represents
the average±s.e.m. (B) Left: microscopic time-lapse images of cultured
neurons from embryonic Xenopus spinal cord expressing GFP (top) and
DN-Rac1-GFP (bottom) at the beginning (0 min) and the end (top, 60 min;
bottom, 120 min) of exposure to an agrin gradient created by the pulsatile
application (arrows) of agrin. Right: superimposed traces depict the
trajectory of the neurite extension during the 1-hour (top, expression of GFP)
and 2-hour (bottom, expression of DN-Rac1-GFP) turning assay. (C) Left:
histogram showing the average turning angles of growth cones from neurons
expressing different constructs in the presence of an agrin gradient (100
µg/ml in the micropipette). Scatter plots show the distribution of the
turning angles of each growth cone. Right: histogram showing the average
neurite extension rate during the turning assay. Scatter plots show the
extension rate of each neurite. Each value represents the
average±s.e.m.; *P<0.01 (Student's
t-test).
|
