Hippocampal neurons respond uniquely to topographies of various sizes and shapes

Abstract

A number of studies have investigated the behavior of neurons on microfabricated topography for the purpose of developing interfaces for use in neural engineering applications. However, there have been few studies simultaneously exploring the effects of topographies having various feature sizes and shapes on axon growth and polarization in the first 24 h. Accordingly, here we investigated the effects of arrays of lines (ridge grooves) and holes of microscale (~2 μm) and nanoscale (~300 nm) dimensions, patterned in quartz (SiO2), on the (1) adhesion, (2) axon establishment (polarization), (3) axon length, (4) axon alignment and (5) cell morphology of rat embryonic hippocampal neurons, to study the response of the neurons to feature dimension and geometry. Neurons were analyzed using optical and scanning electron microscopy. The topographies were found to have a negligible effect on cell attachment but to cause a marked increase in axon polarization, occurring more frequently on sub-microscale features than on microscale features. Neurons were observed to form longer axons on lines than on holes and smooth surfaces; axons were either aligned parallel or perpendicular to the line features. An analysis of cell morphology indicated that the surface features impacted the morphologies of the soma, axon and growth cone. The results suggest that incorporating microscale and sub-microscale topographies on biomaterial surfaces may enhance the biomaterials’ ability to modulate nerve development and regeneration.

SU-8-based nanoporous substrate for migration of neuronal cells

“…Nanopatterned surfaces are known to affect cell behavior, such as attachment [8,9], migration [10], and differentiation [11][12][13][14]. Thus, nanopatterns can be used on the surface of an implantable medical device to control cellular activities for different biomedical applications.…”

Neuronal Electrophysiological Function and Control of Neurite Outgrowth on Electrospun Polymer Nanofibers Are Cell Type Dependent

“…Unlike DRG neurons, Nagata et al showed that central nervous system neuroblasts, including those from the hippocampus, extended neurites primarily perpendicular, but also parallel, to the existing aligned neurite bundles. 42 Later studies extended this to the artificial topographic cues, 43,44 however, parallel hippocampal neurite outgrowth has been reported upon electrospun fibers. 45 DRG and hippocampal neurons provide biomaterial research with two very different neuronal models, representing the two extremes of the neuronal spectrum: a low plasticity peripheral nervous system model that typically does not form networks in culture, and a highly plastic network-forming central nervous system model.…”

Selective axonal growth of embryonic hippocampal neurons according to topographic features of various sizes and shapes

“…In the competitions between the topographies, neurons extended their axons towards the 300 nm lines at a greater frequency than the 2 µm lines, which is consistent with trends reported in the literature showing that smaller lines are more stimulative than larger lines. 14 The competitions between lines and holes indicated that the neurons preferred holes over lines, provided that the different features have an equivalent critical dimension.…”