Calcium imaging reveals wave-like activity in adult retina that is suppressed by an inhibitory network.

<p>A: left panel, A fluorescence image showing loading of calcium indicator OGB-1-AM (green) with superimposed GC (red). Dashed lines indicate position of the recording pipette. Arrowhead points to GC axon. Dark shadow in the left is a blood vessel. Scale bar 80 µm. (A, middle panel) Simultaneous calcium imaging (top) and whole-cell sEPSC traces from GC (bottom). (A, right panel) Cross-correlations between ΔF/F and sEPSCs (right, n = 21) and randomized controls. Note inversed Y-axis to reflect the opposite directions for correlated events – each increase in intracellular calcium (positive) coincides with an inward current (negative). B: A sequence of ΔF/F pseudo color time-lapse images during 12 s of retinal activity viewed from GC side at P47. Blockade of inhibitory feedback reveals the wave-like propagating activity across the retina (middle). This activity is not evident in untreated control conditions (top) and eliminated by application of nifedipine (bottom), a selective antagonist of L-type VGCaCs. Size of the retinal region in each panel is 636× µm. C: Time course of the ΔF/F monitored over 120 s from retinal region marked by a white box in B at various conditions. D: Histogram of wave velocities under SST condition. Bin size is 100 µm/s, n = 130 of waves and n = 4 of retinas. See Supplementary <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0077658#pone.0077658.s001" target="_blank">Videos S1</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0077658#pone.0077658.s004" target="_blank">4</a> for calcium recordings during control, SST and nifedipine conditions in raw (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0077658#pone.0077658.s001" target="_blank">Videos S1</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0077658#pone.0077658.s002" target="_blank">S2</a>) and ΔF/F pseudo color modes (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0077658#pone.0077658.s003" target="_blank">Videos S3</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0077658#pone.0077658.s004" target="_blank">S4</a>) from P47 retinas.