Two-Photon Holographic Stimulation of ReaChR

Chaigneau, Emmanuelle; Ronzitti, Emiliano; Gajowa, Marta; Soler-Llavina, Gilberto; Tanese, Dimitrii; Brureau, Anthony Y. B.; Papagiakoumou, Eirini; Zeng, Hongkui; Emiliani, Valentina

doi:10.3389/fncel.2016.00234

Cited by 67 publications

(94 citation statements)

References 39 publications

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“…2A). Holographic illumination was provided by a fiber amplifier laser source, emitting at 1030 nm and operating at 500 kHz repetition rate (Satsuma HP, Amplitude Systems, France) enabling efficient 2P optogenetic activation of opsins (Chaigneau et al, 2016) (Ronzitti et al, 2017). Calcium imaging was provided by raster scanning a 920-nm beam delivered by a Ti:Sapphire oscillator (Chamaleon Vision II, Coherent Ltd., USA).…”

Section: An All Optical System Combining Holographic Front Shaping Anmentioning

confidence: 99%

All-optical interrogation of a direction selective retinal circuit by holographic wave front shaping

Spampinato

Ronzitti

Zampini

et al. 2019

Preprint

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Direction selective (DS) ganglion cells (GC) in the retina maintain their tuning across a broad range of light levels. Yet very different circuits can shape their responses from bright to dim light, and their respective contributions are difficult to tease apart. In particular, the contribution of the rod bipolar cell (RBC) primary pathway, a key player in dim light, is unclear. To understand its contribution to DSGC response, we designed an all-optical approach allowing precise manipulation of single retinal neurons. Our system activates single cells in the bipolar cell (BC) layer by two-photon (2P) temporally focused holographic illumination, while recording the activity in the ganglion cell layer by 2P Ca 2 imaging. By doing so, we demonstrate that RBCs provide an asymmetric input to DSGCs, suggesting they contribute to their direction selectivity. Our results suggest that every circuit providing an input to direction selective cells can generate direction selectivity by itself. This hints at a general principle to achieve robust selectivity in sensory areas.A major goal in neuroscience is to understand the circuits that embody the computations performed by sensory neurons. In particular, a striking feature of sensory processing is the ability of neurons to perform the same computation in different contexts. For example, neurons in the piriform cortex represent odor identity while remaining invariant to its exact concentration (Bolding and Franks, 2018). Similarly, neurons in the visual cortex can keep the same orientation tuning curve over different contrasts (Sclar and Freeman, 1982).In the retina, direction selective (DS) ganglion cells (GC) respond selectively to a motion direction in different contexts such as different backgrounds (Chen et al., 2016), different natural scenes (Im and Fried, 2016), and over a broad range of luminosities (Pearson and Kerschensteiner, 2015; Vaney et al., 2001;Yao et al., 2018). Switching the average luminance from dim to bright light will change the dominant circuits that convey visual information inside the retina, leading to major changes in the responses of ganglion cells (Pearson and Kerschensteiner, 2015;Wässle, 2004). For example, cells will change their ON-OFF polarity (Tikidji-Hamburyan et al., 2015). It is therefore particularly striking that direction selectivity remains constant across the ten billion fold change of luminance separating day from night (Yao et al., 2018), despite the involvement of distinct circuits. A major challenge is to understand how this feature is achieved.During daylight conditions, where rods are saturated and cones transmit light input, the major component responsible for direction selectivity is a functional asymmetry. This results either from an asymmetric inhibition or an asymmetric morphology. For example, in the ON-OFF

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Section: An All Optical System Combining Holographic Front Shaping Anmentioning

confidence: 99%

All-optical interrogation of a direction selective retinal circuit by holographic wave front shaping

Spampinato

Ronzitti

Zampini

et al. 2019

Preprint

View full text Add to dashboard Cite

show abstract

“…Therefore when we excite a population of neurons unselectively, the brain may inhibit the response since the population activity may not mean anything to the brain (Logothetis et al, 2010). Although it recently became possible to artificially stimulate dozens of cells it is not yet possible to stimulate a whole brain area with a realistic activity pattern (Rickgauer et al, 2014; Packer et al, 2015; Chaigneau et al, 2016). Therefore, we are proposing a non-excitation approach, in which the sole purpose of the inhibitory perturbation is to measure a neuron specific ongoing background input signal.…”

Section: Describing and Verifying Existing Brain Schemesmentioning

confidence: 99%

A Principle for Describing and Verifying Brain Mechanisms Using Ongoing Activity

Eriksson

2017

Front. Neural Circuits

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Not even the most informed scientist can setup a theory that takes all brain signals into account. A neuron not only receives neuronal short range and long range input from all over the brain but a neuron also receives input from the extracellular space, astrocytes and vasculature. Given this complexity, how does one describe and verify a typical brain mechanism in vivo? Common to most described mechanisms is that one focuses on how one specific input signal gives rise to the activity in a population of neurons. This can be an input from a brain area, a population of neurons or a specific cell type. All remaining inputs originating from all over the brain are lumped together into one background input. The division into two inputs is attractive since it can be used to quantify the relative importance of either input. Here we have chosen to extract the specific and the background input by means of recording and inhibiting the specific input. We summarize what it takes to estimate the two inputs on a single trial level. The inhibition should not only be strong but also fast and the specific input measurement has to be tailor-made to the inhibition. In essence, we suggest ways to control electrophysiological experiments in vivo. By applying those controls it may become possible to describe and verify many brain mechanisms, and it may also allow the study of the integration of spontaneous and ongoing activity, which in turn governs cognition and behavior.

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“…after whisker removal. Optogenetic tools in combination with two-photon holographic stimulation (Chaigneau et al 2016)…”

Section: Discussionmentioning

confidence: 99%

Functional and structural properties of highly responsive somatosensory neurons in mouse barrel cortex

Barz

Gardères

Ganea

et al. 2019

Preprint

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Sparse population activity is a hallmark of supra-granular sensory neurons in neocortex.The mechanisms underlying sparseness are not well understood because a direct link between the neurons activated in vivo and their cellular properties investigated in vitro has been missing. We used two-photon calcium imaging to identify a subset of neurons in layer L2/3 (L2/3) of mouse primary somatosensory cortex that are highly active following principal whisker vibrotactile stimulation. These high responders were then 2 tagged using photoconvertible green fluorescent protein for subsequent targeting in the brain slice using intracellular patch-clamp recordings and biocytin staining. This approach allowed us to investigate the structural and functional properties of high responders that distinguish them from less active control cells. Compared to less responsive L2/3 neurons, high responders displayed increased levels of stimulusevoked and spontaneous activity, elevated noise and spontaneous pair-wise correlations, and stronger coupling to the population response. Intrinsic excitability was reduced in high responders, while other electrophysiological and morphological parameters were unchanged. Thus, the choice of which neurons participate in stimulus encoding may largely be determined by network connectivity rather than by cellular structure and function.

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Two-Photon Holographic Stimulation of ReaChR

Cited by 67 publications

References 39 publications

All-optical interrogation of a direction selective retinal circuit by holographic wave front shaping

All-optical interrogation of a direction selective retinal circuit by holographic wave front shaping

A Principle for Describing and Verifying Brain Mechanisms Using Ongoing Activity

Functional and structural properties of highly responsive somatosensory neurons in mouse barrel cortex

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