FIGURE 1.

Neuronal growth on micropatterns. (A) Honeycomb pattern. (B) Dimension of honeycomb pattern. L: edge length of hexagon, D: gap between hexagonal patterns, r₁: radius of a circle covering first nearest neighbors, r₂: radius of a circle covering second nearest neighbors, l₁: length from the center of a hexagonal pattern to the closest edge of a nearest neighboring pattern, l₂: length from the center of a hexagonal pattern to the farthest edge of a nearest neighboring pattern. (C–E) Example image of neurons grown on honeycomb patterns (gray, edge [L]: 55 μm, gap [D]: 50 μm) for 21 days in vitro. (Scale bar: 50 μm). Dendrites stained using MAP2 and honeycomb patterns, and neuritis stained using Tuj1. (F) Representative image of a receptive field (synapse formation zone). Red: synapsin (presynaptic) and Green: PSD95 (postsynaptic). Blue: neurons. Note that patterns are also marked with red fluorescence. Inset: enlarged image of yellow box. (Edge [L]: 55 μm, gap [D]: 30 μm) (scale bar: 50 μm) (G) Probability of cells inside patterns. Error bars: average and SD. (N = 4811 cells from 7 culture samples). (H) Proportion of patterns occupied by cell body, dendrite, and axon with average and SD values. (N: 9436 cells, 32916 patterns, 14 culture samples). (I) Number of patterns occupied by dendrites of individual neurons and normalized histogram (probability). (N: 1360 cells from 2 culture samples). (J) Number of patterns occupied by axons of individual neurons and normalized histogram (probability). (N: 314 cells from 9 culture samples). (K) Average distance from a cell to the three closest neurons. Histogram was normalized as probability [same samples with panel (I)].