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. 2011 Jun 26;14(8):951-2.
doi: 10.1038/nn.2841.

In vivo evidence that retinal bipolar cells generate spikes modulated by light

Elena Dreosti  1 , Federico Esposti, Tom Baden, Leon Lagnado
Affiliations

In vivo evidence that retinal bipolar cells generate spikes modulated by light

Elena Dreosti et al. Nat Neurosci. .

Abstract

Retinal bipolar cells have been assumed to generate purely graded responses to light. To test this idea we imaged the presynaptic calcium transient in live zebrafish. We found that ON, OFF, transient and sustained bipolar cells are all capable of generating fast 'all-or-none' calcium transients modulated by visual stimulation.

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Figures

Figure 1
Figure 1. Imaging fast presynaptic calcium transients in bipolar cells in vivo
a. Synaptic terminals of bipolar cells expressing SyGCaMP2 in a zebrafish (10 dpf). ROIs corresponding to terminals shown below. Scale bar: 20 μm. b. Raster plot showing spontaneous SyGCaMP2 signals in darkness. Sampling interval: 128 ms. c. Spontaneous calcium transients in one terminal. Note the relatively fixed amplitude and time-course. d. Two calcium transients from c on an expanded time-scale. An exponential fit to the first is shown in red (τ = 1.18 s) and superimposed to both spikes. From a sample of 1,008 terminals, 65% generate one or more calcium transients over a 60 s period. e. A single presynaptic calcium transient sampled at 200 Hz (black) and smoothed by interpolation (red). The lower trace is the derivative: the signal describing the rate of calcium influx has a width of 65 ms at half-maximum. All procedures were carried out according to the UK Animals (Scientific Procedures) Act 1986 and approved by the UK Home Office.
Figure 2
Figure 2. Bipolar cells responded to light with both graded signals and spikes
Presynaptic calcium spikes were observed in a variety of functionally distinct bipolar cells. A full-field stimulus (amber; I = 1.7 nW/mm2) was applied at 15 s and modulated around this mean from 25–35 s (square wave, 100% contrast, 2.5 Hz). All traces are examples from individual terminals and have been grouped to show: a, sustained and graded ON terminals; b, sustained and graded OFF; c, transient ON; d, sustained OFF encoding light with spikes; e, transient ON terminals generating calcium spikes in response to temporal contrast; f, terminals generating calcium spikes at low rates but without clear modulation by the stimulus. All scale bars show ΔF/F = 2. g. Sustained ON and OFF terminals also generating spikes (upper and lower traces respectively). h. Upper trace: sustained ON terminal generating a slow response to contrast and then spikes. Lower trace: transient ON cell that spikes at light onset but then generates a slow sustained response to contrast (maximum intensity = 1.7 nW/mm2). Scale bars in g–h show ΔF/F = 1.
See this image and copyright information in PMC

References

    1. Masland RH. Nat Neurosci. 2001;4:877–886. - PubMed
    1. Protti DA, Flores-Herr N, von Gersdorff H. Neuron. 2000;25:215–227. - PubMed
    1. Palmer MJ. J Physiol. 2006;572:747–762. - PMC - PubMed
    1. Dreosti E, Odermatt B, Dorostkar M, Lagnado L. Nature Methods. 2009;6:883–889. - PMC - PubMed
    1. Dorostkar MM, Dreosti E, Odermatt B, Lagnado L. J Neurosci Methods. 2010;188:141–150. - PMC - PubMed

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