FIGURE 4.

Intrathecal delivery of MT-I/II to lumbar DRGs of P28 rats overcomes MAG-mediated inhibition. P28 rats had pumps inserted intrathecally to deliver vehicle (sterile saline) or MT-I/II (0.125, 0.25, and 0.5 μg/μl) to the lumbar DRGs. 24 h later, DRG neurons from the L3, L4, and L5 DRG were cultured onto monolayers of either control (CON) or MAG-expressing (striped bars) or control CHO cells (black bars) and immunostained for βIII tubulin and quantitated for neurite length (300–500 neurons) (A). The graph is an average of three independent experiments with n = 6 for all conditions. Vehicle control neurons grew long processes on control CHO cells (B) but were inhibited in the presence of MAG by an average of 40% (C). Rats that received MT-I/II had significantly longer neurites on MAG at 0.125 μg/μl (D) and a dose-dependent increase in length with 0.25 (E and F) and 0.5 μg/μl (G). Statistics performed are from one-way ANOVA. *, p < 0.05; **, p < 0.01. Scale bar, 20 μm.