Identifying the specific
role of physical guidance cues in the growth of neurons is crucial
for understanding the fundamental biology of brain development and
for designing scaffolds for tissue engineering. Here, we investigate
the structural significance of nanoscale topographies as physical
cues for neurite outgrowth and circuit formation by growing neurons
on semiconductor nanowires. We monitored neurite growth using optical
and scanning electron microscopy and evaluated the spontaneous neuronal
network activity using functional calcium imaging. We show, for the
first time, that an isotropic arrangement of indium phosphide (InP)
nanowires can serve as physical cues for guiding neurite growth and
aid in forming a network with neighboring neurons. Most importantly,
we confirm that multiple neurons, with neurites guided by the topography
of the InP nanowire scaffolds, exhibit synchronized calcium activity,
implying intercellular communications via synaptic connections. Our
study imparts new fundamental insights on the role of nanotopographical
cues in the formation of functional neuronal circuits in the brain
and will therefore advance the development of neuroprosthetic scaffolds