Research Paper Volume 9, Issue 6 pp 1607—1622

Figure 5. Axon growth in vitro is inhibited by GAGs, and more inhibited when GAGs are from PNNs fractions of old brains. (A) Axon outgrowth from adult DRG neurons plated on laminin mixed with CS GAGs from diffuse ECM fraction (B1) of 3 or 18 month old brains. (B) Axon outgrowth from adult DRG neurons plated on laminin mixed with CS GAGs from PNN fraction (B4) of 3 or 18 month old brains. (C) Axon outgrowth from typical adult DRG neurons plated on laminin on laminin alone. (D) Axon outgrowth from adult DRG neurons plated on laminin mixed with CS GAGs from PNN fraction of 18 months brains (B4) and treated with chABC. (E) The graph shows average longest neurite of DRG grown 24 h on each plating condition. All the GAGs inhibit neurite outgrowth when compared with laminin alone; PNNs extracts are more inhibitory than ECM extracts; growth is further reduced when GAGs are from the PNNs fraction of aged brains; chABC treatment partially rescues the inhibitory effect of PNNs extracts from 18 months brains.

Graphs show mean ± s.e.m. Asterisks indicate a significant relationship between average longest neurite and type of GAGs extract used for plating. One Way Anova and Dunnett post-hoc comparisons:***p >0.001, **p =0.002.B1, ECM fraction; B4, PNNs fraction; 3m, 3-month-old brains; 6m, 6-month-old brains; 12m, 12-month-old brains; 18m, 18-month-old brains; C4S, Chondroitin-4-sulfate; C6S, Chondroitin-6-sulfate; lam, laminin; chABC, chondroitinase ABC. Scale bar: 100 µm.