Effect of culture substrata and fibroblast inhibitors: Trigeminal ganglion axon outgrowth revisited

Axon outgrowth in vitro can be influenced profoundly by the culture system used and may even be misleading due to certain prerequisites. intact non-dissociated trigeminal ganglia extend neurites only when cocultured with target tissues and not in isolation. we set out to determine if intact early age murine trigeminal ganglia extend neurites in isolation,is it the culture system involved and whether fibroblast inhibitors could actually prevent the normal outgrowth pattern. mouse intact trigeminal ganglia before target innervation were given the choice to grow in isolation or with target tissues on three dimensional collagen gels,collagen coated platform and poly-d-lysme substrata. cultures in this way were set up in the presence and absence of fibroblast inhibitors. results demonstrated that; firstly,trigeminal ganglia were capable of extending neurites in isolation,secondly,poly-d-lysine promoted extensive outgrowth of neurites,a comparable outgrowth was promoted by collagen substrata but not threedimensional collagen gels. thirdly,inhibitors used to prevent fibroblast outgrowth radically affected the normal outgrowth pattern of neurite fascicles and morphology. where fibroblast inhibitors were omitted,neurites grew to several hundred micrometers distance,highly branched and established intricate neurite-non-neuronal networks. growth cones and filopodia were well developed. additionally,widespread outgrowth occurred only where ganglia were cultured within the first five or ten minutes after removal from embryos. lastly,outgrowth of non-neuronal nonfibroblast cells occurred only when ganglia were cultured without fibroblast inhibitors. we conclude that evaluation of in vitro axon outgrowth and directionality should be cautious. copyright 2010 zoological society of pakistan.