scholarly journals Random spatial patterning of cone bipolar cell mosaics in the mouse retina

2017 ◽  
Vol 34 ◽  
Author(s):  
PATRICK W. KEELEY ◽  
JASON J. KIM ◽  
SAMMY C.S. LEE ◽  
SILKE HAVERKAMP ◽  
BENJAMIN E. REESE
Keyword(s):  
Bipolar Cell ◽  
Amacrine Cells ◽  
Cell Types ◽  
Bipolar Cells ◽  
Statistical Properties ◽  
Horizontal Cells ◽  
Mouse Retina ◽  
Dendritic Arbors ◽  
Cone Bipolar Cells ◽  
Cholinergic Amacrine Cells

AbstractRetinal bipolar cells spread their dendritic arbors to tile the retinal surface, extending them to the tips of the dendritic fields of their homotypic neighbors, minimizing dendritic overlap. Such uniform nonredundant dendritic coverage of these populations would suggest a degree of spatial order in the properties of their somal distributions, yet few studies have examined the patterning in retinal bipolar cell mosaics. The present study examined the organization of two types of cone bipolar cells in the mouse retina, the Type 2 cells and the Type 4 cells, and compared their spatial statistical properties with those of the horizontal cells and the cholinergic amacrine cells, as well as to random simulations of cells matched in density and constrained by soma size. The Delauney tessellation of each field was computed, from which nearest neighbor distances and Voronoi domain areas were extracted, permitting a calculation of their respective regularity indexes (RIs). The spatial autocorrelation of the field was also computed, from which the effective radius and packing factor (PF) were determined. Both cone bipolar cell types were found to be less regular and less efficiently packed than either the horizontal cells or cholinergic amacrine cells. Furthermore, while the latter two cell types had RIs and PFs in excess of those for their matched random simulations, the two types of cone bipolar cells had spatial statistical properties comparable to random distributions. An analysis of single labeled cone bipolar cells revealed dendritic arbors frequently skewed to one side of the soma, as would be expected from a randomly distributed population of cells with dendrites that tile. Taken together, these results suggest that, unlike the horizontal cells or cholinergic amacrine cells which minimize proximity to one another, cone bipolar cell types are constrained only by their physical size.

Rod signals are routed through specific Off cone bipolar cells in primate retina

2020 ◽  
Author(s):  
Amanda J. McLaughlin ◽  
Kumiko A. Percival ◽  
Jacqueline Gayet-Primo ◽  
Teresa Puthussery
Keyword(s):  
Bipolar Cell ◽  
Amacrine Cell ◽  
Amacrine Cells ◽  
Cell Types ◽  
Bipolar Cells ◽  
Visual Signals ◽  
Night Time ◽  
Pass Through ◽  
Aii Amacrine ◽  
Cone Bipolar Cells

AbstractAdapting between scotopic and photopic illumination involves switching the routing of retinal signals between rod and cone-dominated circuits. In the daytime, cone signals pass through parallel On and Off cone bipolar cells, that are sensitive to increments and decrements in luminance, respectively. At night, rod signals are routed into these cone-pathways via a key glycinergic interneuron, the AII amacrine cell (AII-AC). In primates, it is not known whether AII-ACs contact all Off-bipolar cell types indiscriminately, or whether their outputs are biased towards specific Off-bipolar cell types. Here, we show that the rod-driven glycinergic output of AII-ACs is strongly biased towards a subset of macaque Off-cone bipolar cells. The Off-bipolar types that receive this glycinergic input have sustained physiological properties and include the Off-midget bipolar cells, which provide excitatory input to the Off-midget ganglion cells (parvocellular pathway). The kinetics of the glycinergic events are consistent with the involvement of the α1 glycine receptor subunit. Taken together with results in mouse retina, our findings point towards a conserved motif whereby rod signals are preferentially routed into sustained Off signaling pathways.Significance StatementVisual signals pass through different retinal neurons depending on the prevailing level of illumination. Under night-time light levels, signals from rods pass through the AII amacrine cell, an inhibitory interneuron that routes rod signals into On and Off bipolar cells to detect increments and decrements in light intensity, respectively. Here, we show in primate retina that the output of AII amacrine cells is strongly biased towards specific Off bipolar cell types, which suggests that rod signals reach the brain via specific neural channels. Our results further our understanding of how visual signals are routed through visual circuits during night-time vision.

scholarly journals The somal patterning of the AII amacrine cell mosaic in the mouse retina is indistinguishable from random simulations matched for density and constrained by soma size

2018 ◽  
Vol 35 ◽  
Author(s):  
PATRICK W. KEELEY ◽  
BENJAMIN E. REESE
Keyword(s):  
Amacrine Cell ◽  
Amacrine Cells ◽  
Bipolar Cells ◽  
Horizontal Cells ◽  
Mouse Retina ◽  
Retinal Neurons ◽  
Soma Size ◽  
Aii Amacrine Cells ◽  
Aii Amacrine ◽  
Cholinergic Amacrine Cells

AbstractThe orderly spacing of retinal neurons is commonly regarded as a characteristic feature of retinal nerve cell populations. Exemplars of this property include the horizontal cells and the cholinergic amacrine cells, where individual cells minimize the proximity to like-type neighbors, yielding regularity in the patterning of their somata. Recently, two types of retinal bipolar cells in the mouse retina were shown to exhibit an order in their somal patterning no different from density-matched simulations constrained by soma size but being otherwise randomly distributed. The present study has now extended this finding to a type of retinal amacrine cell, the AII amacrine cell. Voronoi domain analysis revealed the patterning in the population of AII amacrine somata to be no different from density-matched and soma-size-constrained random simulations, while analysis of the density recovery profile showed AII amacrine cells to exhibit a minimal intercellular spacing identical to that for those random simulations: AII amacrine somata were positioned side-by-side as often as chance would predict. Regularity indexes and packing factors (PF) were far lower than those achieved by either the horizontal cells or cholinergic amacrine cells, with PFs also being comparable to those derived from the constrained random simulations. These results extend recent findings that call into question the widespread assumption that all types of retinal neurons are assembled as regular somal arrays, and have implications for the way in which AII amacrine cells must distribute their processes to ensure a uniform coverage of the retinal surface.

Glycine stimulates calcium-independent release of 3H-GABA from isolated retinas of Xenopus laevis

1990 ◽  
Vol 4 (4) ◽  
pp. 337-348 ◽  
Author(s):  
John F. Smiley ◽  
Scott F. Basinger
Keyword(s):  
Xenopus Laevis ◽  
Amacrine Cells ◽  
Cell Types ◽  
Bipolar Cells ◽  
Horizontal Cells ◽  
Free Medium ◽  
Ringer’S Solution ◽  
High Concentrations ◽  
Label Density ◽  
Somatostatin 14

AbstractA perfusion system was used to monitor the release of [3H]-GABA from isolated retinas of Xenopus laevis. Measurable release was stimulated by glycine at concentrations as low as 200 μM. Glycine-stimulated release was blocked by strychnine, and was not reduced in “calcium-free” Ringer's solution (0 Ca2+/20 mM Mg2+). Glutamate also stimulated calcium-independent release, using concentrations as low as 100 μM. In contrast, release stimulated by 25 mM potassium was reduced by 80% in calcium-free medium.In most experiments, agonists were applied in six consecutive 4-mm pulses separated by 10-mm washes with Ringer's solution. Under these conditions, the release stimulated by 0.5 mM glutamate or 25 mM potassium decreased by at least 50% from the first to the second pulse, and then gradually decreased with successive applications. In contrast, the response to 0.5 mM glycine at first increased and then only gradually decreased with successive pulses. These patterns of response to different agonists were similar in calcium-free medium.Somatostatin (—14 or —28) also stimulated release, and this effect was inhibited by AOAA, an inhibitor of GABA degradation. In the presence of AOAA, somatostatin had little effect, except at high concentrations of somatostatin (5 μM), which increased both basal and glycine-stimulated release. In contrast to somatostatin, glycine-stimulated release was much larger in the presence of AOAA.Autoradiography was used to investigate which cell types released [3H]-GABA under our conditions. Autoradiograms showed that horizontal cells and a population of apparent “off” bipolar cells were well-labeled by [3H]-GABA high-affinity uptake. In addition, light labeling was seen over numerous amacrine cells. After application of glycine, glutamate, or potassium, there was a decrease in label density over horizontal cells.

GABA inhibits ACh release from the rabbit retina: A direct effect or feedback to bipolar cells?

1992 ◽  
Vol 8 (2) ◽  
pp. 97-106 ◽  
Author(s):  
David M. Linn ◽  
Stephen C. Massey
Keyword(s):  
Direct Effect ◽  
Negative Feedback ◽  
Bipolar Cell ◽  
Amacrine Cells ◽  
Bipolar Cells ◽  
Rabbit Retina ◽  
Ach Release ◽  
Gaba Antagonists ◽  
Direct Input ◽  
Cholinergic Amacrine Cells

AbstractThe cholinergic amacrine cells of the rabbit retina may be labeled with [3H]-Ch and the activity of the cholinergic population monitored by following the release of [3H]-ACh. We have tested the effect of muscimol, a potent GABAA agonist, on (1) the light-evoked release of ACh, presumably mediated via bipolar cells, which are known to have a direct input to the cholinergic amacrine cells and (2) ACh release produced by exogenous glutamate analogs that probably have a direct effect on cholinergic amacrine cells. Muscimol blocked the light-evoked release of ACh with an IC50 of 1.0 μM. In contrast, ACh release produced by nonsaturating doses of kainate or NMDA was not reduced even by 100 μM muscimol. Thus, we have been unable to demonstrate a direct effect of GABA on the cholinergic amacrine cells.GABA antagonists, such as picrotoxin, caused a large increase in the base release and potentiated the light-evoked release of ACh. Both these effects were abolished by DNQX, a kainate antagonist that blocks the input to cholinergic amacine cells from bipolar cells. DNQX blocked the effects of picrotoxin even when controls showed that the mechanism of ACh release was still functional. Together, these results imply that the dominant site for the GABA-mediated inhibition of ACh release is on the bipolar cell input to the cholinergic amacrine cells. This is consistent with previous anatomical and physiological evidence that bipolar cells receive negative feedback from GABA amacrine cells.

scholarly journals Dark-adapted response threshold of OFF ganglion cells is not set by OFF bipolar cells in the mouse retina

2012 ◽  
Vol 107 (10) ◽  
pp. 2649-2659 ◽  
Author(s):  
A. Cyrus Arman ◽  
Alapakkam P. Sampath
Keyword(s):  
Ganglion Cells ◽  
Amacrine Cells ◽  
Bipolar Cells ◽  
Response Threshold ◽  
Mouse Retina ◽  
Signal Flow ◽  
Visual Threshold ◽  
Aii Amacrine Cells ◽  
Aii Amacrine ◽  
Cone Bipolar Cells

The nervous system frequently integrates parallel streams of information to encode a broad range of stimulus strengths. In mammalian retina it is generally believed that signals generated by rod and cone photoreceptors converge onto cone bipolar cells prior to reaching the retinal output, the ganglion cells. Near absolute visual threshold a specialized mammalian retinal circuit, the rod bipolar pathway, pools signals from many rods and converges on depolarizing (AII) amacrine cells. However, whether subsequent signal flow to OFF ganglion cells requires OFF cone bipolar cells near visual threshold remains unclear. Glycinergic synapses between AII amacrine cells and OFF cone bipolar cells are believed to relay subsequently rod-driven signals to OFF ganglion cells. However, AII amacrine cells also make glycinergic synapses directly with OFF ganglion cells. To determine the route for signal flow near visual threshold, we measured the effect of the glycine receptor antagonist strychnine on response threshold in fully dark-adapted retinal cells. As shown previously, we found that response threshold for OFF ganglion cells was elevated by strychnine. Surprisingly, strychnine did not elevate response threshold in any subclass of OFF cone bipolar cell. Instead, in every OFF cone bipolar subclass strychnine suppressed tonic glycinergic inhibition without altering response threshold. Consistent with this lack of influence of strychnine, we found that the dominant input to OFF cone bipolar cells in darkness was excitatory and the response threshold of the excitatory input varied by subclass. Thus, in the dark-adapted mouse retina, the high absolute sensitivity of OFF ganglion cells cannot be explained by signal transmission through OFF cone bipolar cells.

Unique functional properties of the APB sensitive and insensitive rod pathways signaling light decrements in mouse retinal ganglion cells

2006 ◽  
Vol 23 (1) ◽  
pp. 127-135 ◽  
Author(s):  
GUO-YONG WANG
Keyword(s):  
Functional Properties ◽  
Ganglion Cells ◽  
Amacrine Cells ◽  
Bipolar Cells ◽  
Mouse Retina ◽  
Clear Cut ◽  
Types Of Information ◽  
Rod Bipolar Cells ◽  
Rod Pathway ◽  
Cone Bipolar Cells

Light decrements are mediated by two distinct groups of rod pathways in the dark-adapted retina that can be differentiated on the basis of their sensitivity to the glutamate agonist DL-2-amino-phosphonobutyric (APB). By means of the APB sensitive pathway, rods transmit light decrementsviarod bipolar cells to AII amacrine cells, then to Off cone bipolar cells, which in turn innervate the dendrites of Off ganglion cells. APB hyperpolarizes rod bipolar cells, thus blocking this rod pathway. With APB insensitive pathways, rods either directly synapse onto Off cone bipolar cells, or rods pass light decrement signal to cones by gap junctions. In the present study, whole-cell patch-clamp recordings were made from ganglion cells in the dark-adapted mouse retina to investigate the functional properties of APB sensitive and insensitive rod pathways. The results revealed several clear-cut differences between the APB sensitive and APB insensitive rod pathways. The latency of Off responses to a flashing spot of light was significantly shorter for the APB insensitive pathways than those for the APB sensitive pathway. Moreover, Off responses of the APB insensitive pathways were found to be capable of following substantially higher stimulus frequencies. Nitric oxide was found to selectively block Off responses in the APB sensitive rod pathway. Collectively, these results provide evidence that the APB sensitive and insensitive rod pathways can convey different types of information signaling light decrements in the dark-adapted retina.

scholarly journals Dendro-somatic synaptic inputs to ganglion cells violate receptive field and connectivity rules in the mammalian retina

2021 ◽  
Author(s):  
Miloslav Sedlacek ◽  
William Grimes ◽  
Morgan Musgrove ◽  
Amurta Nath ◽  
Hua Tian ◽  
...  
Keyword(s):  
Receptive Field ◽  
Ganglion Cells ◽  
Plexiform Layer ◽  
Amacrine Cells ◽  
Cell Types ◽  
Excitatory Input ◽  
Mouse Retina ◽  
Inner Plexiform Layer ◽  
Visual Response ◽  
Dendritic Arbors

In retinal neurons, morphology strongly influences visual response features. Ganglion cell (GC) dendrites ramify in distinct strata of the inner plexiform layer (IPL) so that GCs responding to light increments (ON) or decrements (OFF) receive appropriate excitatory inputs. This vertical stratification prescribes response polarity and ensures consistent connectivity between cell types, whereas the lateral extent of GC dendritic arbors typically dictates receptive field (RF) size. Here, we identify circuitry in mouse retina that contradicts these conventions. A2 amacrine cells are interneurons understood to mediate 'cross-over' inhibition by relaying excitatory input from the ON layer to inhibitory outputs in the OFF layer. Ultrastructural and physiological analyses show, however, that some A2s deliver powerful inhibition to OFF GC somas and proximal dendrites in the ON layer, rendering their inhibitory RFs smaller than their dendritic arbors. This OFF pathway, avoiding entirely the OFF region of the IPL, challenges several tenets of retinal circuitry.

scholarly journals Center-surround interactions underlie bipolar cell motion sensing in the mouse retina

2021 ◽  
Author(s):  
Sarah Strauss ◽  
Maria M Korympidou ◽  
Yanli Ran ◽  
Katrin Franke ◽  
Timm Schubert ◽  
...  
Keyword(s):  
Bipolar Cell ◽  
Ganglion Cells ◽  
Receptive Fields ◽  
Amacrine Cells ◽  
Bipolar Cells ◽  
Mouse Retina ◽  
Motion Processing ◽  
Local Motion ◽  
Motion Sensing ◽  
Motion Sensitivity

Motion is a critical aspect of vision. We studied the representation of motion in mouse retinal bipolar cells and found, surprisingly, that some bipolar cells possess motion-sensing capabilities that rely on their center-surround receptive fields. Using a glutamate sensor, we directly observed motion-sensitive bipolar cell synaptic output, which was strongest for local motion and dependent on the motion's origin. We characterized bipolar cell receptive fields and found that there are motion and non-motion sensitive bipolar cell types, the majority being motion sensitive. Next, we used these bipolar cell receptive fields along with connectomics to design biophysical models of downstream cells. The models and experiments demonstrated that bipolar cells pass motion-sensitive excitation to starburst amacrine cells through direction-specific signals mediated by bipolar cells' center-surround receptive field structure. As bipolar cells provide excitation to most amacrine and ganglion cells, their motion sensitivity may contribute to motion processing throughout the visual system.

Morphological and functional identifications of catfish retinal neurons. I. Classical morphology

1975 ◽  
Vol 38 (1) ◽  
pp. 53-71 ◽  
Author(s):  
K. Naka ◽  
N. R. Garraway
Keyword(s):  
Ganglion Cells ◽  
Horizontal Cell ◽  
Dendritic Tree ◽  
Amacrine Cells ◽  
Cell Types ◽  
Bipolar Cells ◽  
Inner Nuclear Layer ◽  
Horizontal Cells ◽  
Specific Cell ◽  
Definition Of

The morphology of the catfish horizontal cells is comparable to that in other fish retinas. The external horizontal cells contact cone receptors and are stellate in shape; the intermediate horizontal cells are even more so and contact rod receptors. The internal horizontal cells constitute the most proximal layer of the inner nuclear layer and may possibly be, in reality, extended processes from the other two horizontal cell types. Bipolar cells resemble those in other teleost retinas: the size and shape of their dendritic tree encompass a continuous spectrum ranging from what is known as the small to the large bipolar cells. The accepted definition of amacrine cells is sufficiently vague to justify our originating a more descriptive and less inferential name for the (axonless) neurons in the inner nuclear layer which radiate processes throughout the inner synaptic layer. These starbust and spaghetti cells vary considerably in the character and extent of their dendritic spread, but correlates exist in other vertebrate retinas. Ganglion cells are found not only in the classical ganglion layer but displaced into the inner nuclear layer as well. Several types can be distinguished on the basis of cell geometry and by the properties of their dendritic tree. Not all of the categorization corresponds with previous descriptions; our findings suggest that some reorganization may be necessary in the accepted classification of cells in the proximal areas of the vertebrate retina. A subtle yet remarkable pattern underlies the entire structure of the catfish retina; there exists a definite gradient of size within a particular class of cells, and of configuration among the subclasses of a specific cell type. It remains to be seen if these morphological spectra bear any functional consequences. The fact that the structure of the catfish retina most closely resembles those of other phylogenetically ancient animals, such as the skate and the dogfish shark, testifies to its primitive organization; morphological and functional mechanisms discernible in this simple system may, therefore, be applicable to the retinas of higher ordered vertebrates.

scholarly journals Dopamine D1 receptor activation reduces local inner retinal inhibition to light-adapted levels

2019 ◽  
Vol 121 (4) ◽  
pp. 1232-1243 ◽  
Author(s):  
Reece E. Mazade ◽  
Michael D. Flood ◽  
Erika D. Eggers
Keyword(s):  
Bipolar Cell ◽  
Light Adaptation ◽  
Amacrine Cells ◽  
Receptor Activation ◽  
Bipolar Cells ◽  
D1 Receptor ◽  
D1 Receptors ◽  
Local Inhibition ◽  
Local Circuits ◽  
Cone Bipolar Cells

During adaptation from dim to bright environments, changes in retinal signaling are mediated, in part, by dopamine. Dopamine is released with light and can modulate retinal receptive fields, neuronal coupling, inhibitory receptors, and rod pathway inhibition. However, it is unclear how dopamine affects inner retinal inhibition to cone bipolar cells, which relay visual information from photoreceptors to ganglion cells and are important signal processing sites. We tested the hypothesis that dopamine (D)1 receptor activation is sufficient to elicit light-adapted inhibitory changes. Local light-evoked inhibition and spontaneous activity were measured from OFF cone bipolar cells in dark-adapted mouse retinas while stimulating D1 receptors, which are located on bipolar, horizontal, and inhibitory amacrine cells. The D1 agonist SKF38393 reduced local inhibitory light-evoked response magnitude and increased response transience, which mimicked changes measured with light adaptation. D1-mediated reductions in local inhibition were more pronounced for glycinergic than GABAergic inputs, comparable with light adaptation. The effects of D1 receptors on light-evoked input were similar to the effects on spontaneous input. D1 receptor activation primarily decreased glycinergic spontaneous current frequency, similar to light adaptation, suggesting mainly a presynaptic amacrine cell site of action. These results expand the role of dopamine to include signal modulation of cone bipolar cell local inhibition. In this role, D1 receptor activation, acting primarily through glycinergic amacrine cells, may be an important mechanism for the light-adapted reduction in OFF bipolar cell inhibition since the actions are similar and dopamine is released during light adaptation. NEW & NOTEWORTHY Retinal adaptation to different luminance conditions requires the adjustment of local circuits for accurate signaling of visual scenes. Understanding mechanisms behind luminance adaptation at different retinal levels is important for understanding how the retina functions in a dynamic environment. In the mouse, we show that dopamine pathways reduce inner retinal inhibition similar to increased background luminance, suggesting the two are linked and highlighting a possible mechanism for light adaptation at an early retinal processing center.

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