Neurite growth cones detect and respond to guidance cues in their loca
l environment that determine stereotyped pathways during development a
nd regeneration. Micropatterns of laminin (which was found to adsorb p
referentially to photolithographically defined hydrophobic areas of mi
cropatterns) were here used to model adhesive pathways that might infl
uence neurite extension. The responses of growth cones were determined
by the degree of guidance of neurite extension and also by examining
growth cone morphology. These parameters were found to be strongly dep
endent on the geometry of the patterned laminin, and on neuron type. D
ecreasing the spacing of multiple parallel tracks of laminin alternati
ng with non-adhesive tracks, resulted in decreased guidance of chick e
mbryo brain neurons. Single isolated 2 mum tracks strongly guided neur
ite extension whereas 2 mum tracks forming a 4 mum period multiple par
allel pattern did not. Growth cones appear to be capable of bridging t
he narrow non-adhesive tracks, rendering them insensitive to the small
er period multiple parallel adhesive patterns. These observations sugg
est that growth cones would be unresponsive to the multiple adhesive c
ues such as would be presented by oriented extracellular matrix or cer
tain axon fascicle structures, but could be guided by isolated adhesiv
e tracks. Growth cone morphology became progressively simpler on progr
essively narrower single tracks. On narrow period multiple parallel tr
acks (which did not guide neurite extension) growth cones spanned a nu
mber of adhesive/non-adhesive tracks, and their morphology suggests th
at lamellipodial advance may be independent of the substratum by using
filopodia as a scaffold. In addition to acting as guidance cues, lami
nin micropatterns also appeared to influence the production of primary
neurites and their subsequent branching. On planar substrata, dorsal
root ganglion neurons were multipolar, with highly branched neurite ou
tgrowth whereas, on 25 mum tracks, neurite branching was reduced or ab
sent, and neuron morphology was typically bipolar. These observations
indicate the precision with which growth cone advance may be controlle
d by substrata and suggest a role for patterned adhesiveness in neuron
al morphological differentiation, but also high-light some of the limi
tations of growth cone sensitivity to substratum cues.