scholarly journals Nonlinearities in retinal bipolar cells shape the encoding of artificial and natural stimuli

2020 ◽  
Author(s):  
Helene Marianne Schreyer ◽  
Tim Gollisch
Keyword(s):  
Receptive Field ◽  
Bipolar Cells ◽  
Spatial Integration ◽  
Nonlinear Properties ◽  
Natural Stimuli ◽  
Cell Type Specific ◽  
Linear Signal ◽  
Parallel Feature ◽  
Nonlinear Signal ◽  
Receptive Field Center

AbstractThe retina dissects the visual scene into parallel feature channels, and bipolar cells are speculated to play a key role in this signal separation. Yet, bipolar cells are traditionally viewed as simple, linear neurons. Here, using the salamander retina, we investigated the hypothesis of linear signal processing in bipolar cells by intracellularly recording their voltage signals under artificial and natural visual stimuli. We observed nonlinear representation of contrast and, unexpectedly, also nonlinear spatial integration in a sizable fraction of bipolar cells. Furthermore, linear receptive field models fail to describe responses of nonlinear bipolar cells to spatially structured artificial and natural stimuli. The nonlinear properties occur in the receptive field center and may be cell-type specific, with stronger effects in transient than sustained bipolar cells. Thus, our data suggest that nonlinear signal pooling starts earlier than previously thought, that is, before signal integration in bipolar cells.

scholarly journals Receptive field center-surround interactions mediate context-dependent spatial contrast encoding in the retina

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Maxwell H Turner ◽  
Gregory W Schwartz ◽  
Fred Rieke
Keyword(s):  
Receptive Field ◽  
Spatial Structure ◽  
Ganglion Cell ◽  
Sensory Processing ◽  
Visual Information ◽  
Macaque Monkey ◽  
Retinal Ganglion ◽  
Natural Stimuli ◽  
The Impact ◽  
Receptive Field Center

Antagonistic receptive field surrounds are a near-universal property of early sensory processing. A key assumption in many models for retinal ganglion cell encoding is that receptive field surrounds are added only to the fully formed center signal. But anatomical and functional observations indicate that surrounds are added before the summation of signals across receptive field subunits that creates the center. Here, we show that this receptive field architecture has an important consequence for spatial contrast encoding in the macaque monkey retina: the surround can control sensitivity to fine spatial structure by changing the way the center integrates visual information over space. The impact of the surround is particularly prominent when center and surround signals are correlated, as they are in natural stimuli. This effect of the surround differs substantially from classic center-surround models and raises the possibility that the surround plays unappreciated roles in shaping ganglion cell sensitivity to natural inputs.

scholarly journals A model of high-frequency oscillatory potentials in retinal ganglion cells

2003 ◽  
Vol 20 (5) ◽  
pp. 465-480 ◽  
Author(s):  
GARRETT T. KENYON ◽  
BARTLETT MOORE ◽  
JANELLE JEFFS ◽  
KATE S. DENNING ◽  
GREG J. STEPHENS ◽  
...  
Keyword(s):  
Receptive Field ◽  
High Frequency ◽  
Spatial Organization ◽  
Ganglion Cells ◽  
Amacrine Cells ◽  
Oscillatory Potentials ◽  
Nonlinear Properties ◽  
Field Center ◽  
Receptive Field Center ◽  
High Frequency Oscillatory

High-frequency oscillatory potentials (HFOPs) have been recorded from ganglion cells in cat, rabbit, frog, and mudpuppy retina and in electroretinograms (ERGs) from humans and other primates. However, the origin of HFOPs is unknown. Based on patterns of tracer coupling, we hypothesized that HFOPs could be generated, in part, by negative feedback from axon-bearing amacrine cells excited via electrical synapses with neighboring ganglion cells. Computer simulations were used to determine whether such axon-mediated feedback was consistent with the experimentally observed properties of HFOPs. (1) Periodic signals are typically absent from ganglion cell PSTHs, in part because the phases of retinal HFOPs vary randomly over time and are only weakly stimulus locked. In the retinal model, this phase variability resulted from the nonlinear properties of axon-mediated feedback in combination with synaptic noise. (2) HFOPs increase as a function of stimulus size up to several times the receptive-field center diameter. In the model, axon-mediated feedback pooled signals over a large retinal area, producing HFOPs that were similarly size dependent. (3) HFOPs are stimulus specific. In the model, gap junctions between neighboring neurons caused contiguous regions to become phase locked, but did not synchronize separate regions. Model-generated HFOPs were consistent with the receptive-field center dynamics and spatial organization of cat alpha cells. HFOPs did not depend qualitatively on the exact value of any model parameter or on the numerical precision of the integration method. We conclude that HFOPs could be mediated, in part, by circuitry consistent with known retinal anatomy.

scholarly journals Receptive field center-surround interactions mediate context-dependent spatial contrast encoding in the retina

2018 ◽  
Author(s):  
Maxwell H. Turner ◽  
Gregory W. Schwartz ◽  
Fred Rieke
Keyword(s):  
Receptive Field ◽  
Spatial Structure ◽  
Ganglion Cell ◽  
Sensory Processing ◽  
Visual Information ◽  
Retinal Ganglion ◽  
Natural Stimuli ◽  
The Impact ◽  
Receptive Field Center

SummaryAntagonistic receptive field surrounds are a near-universal property of early sensory processing. A key assumption in many models for retinal ganglion cell encoding is that receptive field surrounds are added only to the fully formed center signal. But anatomical and functional observations indicate that surrounds are added before the summation of signals across receptive field subunits that creates the center. Here, we show that this receptive field architecture has an important consequence for spatial contrast encoding: the surround can control sensitivity to fine spatial structure by changing the way the center integrates visual information over space. The impact of the surround is particularly prominent when center and surround signals are correlated, as they are in natural stimuli. This role of the surround differs substantially from classic center-surround models and raises the possibility that the surround plays unappreciated roles in shaping ganglion cell sensitivity to natural inputs.

scholarly journals Nonlinear spatial integration underlies the diversity of retinal ganglion cell responses to natural stimuli

2020 ◽  
Author(s):  
Dimokratis Karamanlis ◽  
Tim Gollisch
Keyword(s):  
Receptive Field ◽  
Ganglion Cells ◽  
Receptive Fields ◽  
Mouse Retina ◽  
Spatial Integration ◽  
Natural Stimuli ◽  
Crucial Component ◽  
Nonlinear Processing ◽  
Standard Linear ◽  
Sensory Encoding

AbstractHow neurons encode natural stimuli is a fundamental question for sensory neuroscience. In the early visual system, standard encoding models assume that neurons linearly filter incoming stimuli through their receptive fields, but artificial stimuli, such as reversing gratings, often reveal nonlinear spatial processing. We investigated whether such nonlinear processing is relevant for the encoding of natural images in ganglion cells of the mouse retina. We found that standard linear receptive field models fail to capture the spiking activity for a large proportion of cells. These cells displayed pronounced sensitivity to fine spatial contrast, and local signal rectification was identified as the dominant nonlinearity. In addition, we also observed a class of nonlinear ganglion cells with opposite tuning for spatial contrast and a particular sensitivity for spatially homogeneous stimuli. Our work highlights receptive field nonlinearities as a crucial component for understanding early sensory encoding in the context of natural stimuli.

Color-opponent responses of small and giant bipolar cells in the carp retina

2000 ◽  
Vol 17 (4) ◽  
pp. 609-621 ◽  
Author(s):  
KIYOSHI SHIMBO ◽  
JUN-ICHI TOYODA ◽  
HIROAKI KONDO ◽  
TORU KUJIRAOKA
Keyword(s):  
Receptive Field ◽  
Spectral Characteristic ◽  
Short Wavelength ◽  
Opposite Polarity ◽  
Bipolar Cells ◽  
Morphological Properties ◽  
Long Wavelength ◽  
Green Spot ◽  
Ionic Mechanisms ◽  
Receptive Field Center

The physiological and morphological properties of color-opponent bipolar cells in the carp retina were studied. Fifty nine OFF-center bipolar cells and 63 ON-center bipolar cells out of about 500 total bipolar cells recorded showed color-opponent responses. The OFF-center color-opponent bipolar cells were classified into three subgroups according to their spectral and spatial responses. Fifty OFF-center color-opponent cells responded with depolarization to a blue light spot and with hyperpolarization to a red spot in the receptive-field center. The polarity of the surround response was opposite to that of center response at each wavelength. Therefore these cells were classified as OFF double-opponent cells (OFF-DO). Eight cells responded with hyperpolarization to a blue and green spot and with depolarization to a red spot. The surround responses of those cells were depolarizing at any wavelength (R+G− cell). One responded with hyperpolarization to a blue and red spot and with depolarization to a green spot. The surround response showed a different spectral characteristic from that of the center response. It responded with depolarization to a blue and green annulus and with hyperpolarization to a red annulus (R−G+B− cell). The ON-center color-opponent bipolar cells were similarly classified into three subgroups. Sixty of ON-center color-opponent cells were the double color-opponent type (ON-DO cell), showing the responses of opposite polarity to the OFF-DO cells. Two cells were classified as R−G+ cell, and one cell as R+G−B+ cell. Both OFF- and ON-DO cells were identified by their morphology as Cajal's giant bipolar cells, and R+G−, R−G+, R−G+B−, and R+G−B+ cells as Cajal's small bipolar cells. The analysis of the latency and the ionic mechanisms of their responses suggest that DO cells under light-adapted conditions receive direct inputs from long-wavelength (red) cones, RG cells from middle-wavelength (green) cones, and RGB cells from short-wavelength (blue) cones. Possible mechanisms of the opponent inputs to these bipolar cells are discussed.

scholarly journals Nature and Interaction of Signals From the Receptive Field Center and Surround in Macaque V1 Neurons

2002 ◽  
Vol 88 (5) ◽  
pp. 2530-2546 ◽  
Author(s):  
James R. Cavanaugh ◽  
Wyeth Bair ◽  
J. Anthony Movshon
Keyword(s):  
Receptive Field ◽  
Field Model ◽  
Neuronal Response ◽  
Field Size ◽  
Spatial Integration ◽  
Receptive Field Size ◽  
V1 Neurons ◽  
Field Center ◽  
Horizontal Connections ◽  
Receptive Field Center

Information is integrated across the visual field to transform local features into a global percept. We now know that V1 neurons provide more spatial integration than originally thought due to the existence of their nonclassical inhibitory surrounds. To understand spatial integration in the visual cortex, we have studied the nature and extent of center and surround influences on neuronal response. We used drifting sinusoidal gratings in circular and annular apertures to estimate the sizes of the receptive field's excitatory center and suppressive surround. We used combinations of stimuli inside and outside the receptive field to explore the nature of the surround influence on the receptive field center as a function of the relative and absolute contrast of stimuli in the two regions. We conclude that the interaction is best explained as a divisive modulation of response gain by signals from the surround. We then develop a receptive field model based on the ratio of signals from Gaussian-shaped center and surround mechanisms. We show that this model can account well for the variations in receptive field size with contrast that we and others have observed and for variations in size with the state of contrast adaptation. The model achieves this success by simple variations in the relative gain of the two component mechanisms of the receptive field. This model thus offers a parsimonious explanation of a variety of phenomena involving changes in apparent receptive field size and accounts for these phenomena purely in terms of two receptive field mechanisms that do not themselves change in size. We used the extent of the center mechanism in our model as an indicator of the spatial extent of the central excitatory portion of the receptive field. We compared the extent of the center to measurements of horizontal connections within V1 and determined that horizontal intracortical connections are well matched in extent to the receptive field center mechanism. Input to the suppressive surround may come in part from feedback signals from higher areas.

Comparison of the responses of AII amacrine cells in the dark- and light-adapted rabbit retina

1999 ◽  
Vol 16 (4) ◽  
pp. 653-665 ◽  
Author(s):  
DAIYAN XIN ◽  
STEWART A. BLOOMFIELD
Keyword(s):  
Receptive Field ◽  
Light Adaptation ◽  
Amacrine Cells ◽  
Bipolar Cells ◽  
Rabbit Retina ◽  
Response Component ◽  
Synaptic Inputs ◽  
Field Organization ◽  
Receptive Field Organization ◽  
Aii Amacrine Cells

We studied the light-evoked responses of AII amacrine cells in the rabbit retina under dark- and light-adapted conditions. In contrast to the results of previous studies, we found that AII cells display robust responses to light over a 6–7 log unit intensity range, well beyond the operating range of rod photoreceptors. Under dark adaptation, AII cells showed an ON-center/OFF-surround receptive-field organization. The intensity–response profile of the center-mediated response component followed a dual-limbed sigmoidal function indicating a transition from rod to cone mediation as stimulus intensities were increased. Following light adaptation, the receptive-field organization of AII cells changed dramatically. Light-adapted AII cells showed both ON- and OFF-responses to stimulation of the center receptive field, but we found no evidence for an antagonistic surround. Interestingly, the OFF-center response appeared first following rapid light adaptation and was then replaced gradually over a 1–4 min period by the emerging ON-center response component. Application of the metabotropic glutamate receptor agonist APB, the ionotropic glutamate blocker CNQX, 8-bromo-cGMP, and the nitric oxide donor SNAP all showed differential effects on the various center-mediated responses displayed by dark- and light-adapted AII cells. Taken together, these pharmacological results indicated that different synaptic circuits are responsible for the generation of the different AII cell responses. Specifically, the rod-driven ON-center responses are apparently derived from rod bipolar cell synaptic inputs, whereas the cone-driven ON-center responses arise from signals crossing the gap junctions between AII cells and ON-center cone bipolar cells. Additionally, the OFF-center response of light-adapted AII cells reflects direct synaptic inputs from OFF-center cone bipolar cells to AII dendritic processes in the distal inner plexiform layer.

scholarly journals Femtosecond Laser Fabrication of Hybrid Metal-Dielectric Structures with Nonlinear Photoluminescence

Photonics ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 121
Author(s):  
Ekaterina Ponkratova ◽  
Eduard Ageev ◽  
Filipp Komissarenko ◽  
Sergei Koromyslov ◽  
Dmitry Kudryashov ◽  
...  
Keyword(s):  
Visible Spectral Region ◽  
Single Step ◽  
Hybrid Nanostructures ◽  
Nonlinear Properties ◽  
Nanophotonic Devices ◽  
Sensing Applications ◽  
Structure Morphology ◽  
Wide Range ◽  
Nonlinear Signal ◽  
Dielectric Structures

Fabrication of hybrid micro- and nanostructures with a strong nonlinear response is challenging and represents a great interest due to a wide range of photonic applications. Usually, such structures are produced by quite complicated and time-consuming techniques. This work demonstrates laser-induced hybrid metal-dielectric structures with strong nonlinear properties obtained by a single-step fabrication process. We determine the influence of several incident femtosecond pulses on the Au/Si bi-layer film on produced structure morphology. The created hybrid systems represent isolated nanoparticles with a height of 250–500 nm exceeding the total thickness of the Au-Si bi-layer. It is shown that fabricated hybrid nanostructures demonstrate enhancement of the SHG signal (up to two orders of magnitude) compared to the initial planar sample and a broadband photoluminescence signal (more than 200 nm in width) in the visible spectral region. We establish the correlation between nonlinear signal and phase composition provided by Raman scattering measurements. Such laser-induced structures have significant potential in optical sensing applications and can be used as components for different nanophotonic devices.

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