Figure 3

Stiff substrate increases synchronized spontaneous cytosolic Ca²⁺ oscillations in cultured neural networks of hippocampal neurons.

(a) Representative single cell images showing Ca²⁺ fluorescence in DIV14–18 neurons on stiff substrates. (b) Representative single cell images showing Ca²⁺ fluorescence intensity at given time points from one neuron on soft substrate and another neuron on stiff substrate. (c) Representative time elapse recordings of Ca²⁺ oscillations from neurons on soft and stiff substrates. (d) Summary of the basal cytosolic Ca²⁺ concentrations (left) and the magnitude (middle) and frequency (right) of Ca²⁺ oscillations in 58 neurons on soft and stiff substrates from three preparations. *, p < 0.05 denotes significant difference and NS, no significant difference. (g) Left: representative single cell images showing Ca²⁺ fluorescence in DIV14–18 neurons on soft and stiff substrates. Right: time elapse recordings of Ca²⁺ oscillations from four neurons as denoted by circles in the left images.