scholarly journals Sophisticated Temporal Pattern Recognition in Retinal Ganglion Cells

2008 ◽  
Vol 99 (4) ◽  
pp. 1787-1798 ◽  
Author(s):  
Greg Schwartz ◽  
Michael J. Berry
Keyword(s):  
Pattern Recognition ◽  
Retinal Ganglion Cells ◽  
Visual Processing ◽  
Temporal Pattern ◽  
Ganglion Cells ◽  
Amacrine Cells ◽  
Ambystoma Tigrinum ◽  
Time Interval ◽  
Retinal Ganglion ◽  
Temporal Pattern Recognition

Pattern recognition is one of the most important tasks of the visual system, and uncovering the neural mechanisms underlying recognition phenomena has been a focus of researchers for decades. Surprisingly, at the earliest stages of vision, the retina is capable of highly sophisticated temporal pattern recognition. We stimulated the retina of tiger salamander ( Ambystoma tigrinum) with periodic dark flash sequences and found that retinal ganglion cells had a wide variety of different responses to a periodic flash sequence with many firing when a flash was omitted. The timing of the omitted stimulus response (OSR) depended on the period, with individual cells tracking the stimulus period down to increments of 5 ms. When flashes occurred earlier than expected, cells updated their expectation of the next flash time by as much as 50 ms. When flashes occurred later than expected, cells fired an OSR and reset their temporal expectation to the average time interval between flashes. Using pharmacology to investigate the retinal circuitry involved, we found that inhibitory transmission from amacrine cells was not required, but on bipolar cells were required. The results suggest a mechanism in which the intrinsic resonance of on bipolars leads to the OSR in ganglion cells. We discuss the implications of retinal pattern recognition on the neural code of the retina and visual processing in general.

scholarly journals Expression of a Barhl1a reporter in subsets of retinal ganglion cells and commissural neurons of the developing zebrafish brain

2020 ◽  
Author(s):  
Shahad Albadri ◽  
Olivier Armant ◽  
Tairi Aljand-Geschwill ◽  
Filippo Del Bene ◽  
Matthias Carl ◽  
...  
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Amacrine Cells ◽  
Optic Chiasm ◽  
Retinal Ganglion ◽  
Commissural Neurons ◽  
Axonal Projections ◽  
Underlying Mechanisms ◽  
And Function

AbstractPromoting the regeneration or survival of retinal ganglion cells (RGCs) is one focus of regenerative medicine. Homeobox Barhl transcription factors might be instrumental in these processes. In mammals, only barhl2 is expressed in the retina and is required for both subtype identity acquisition of amacrine cells and for the survival of RGCs downstream of Atoh7, a transcription factor necessary for RGC genesis. The underlying mechanisms of this dual role of Barhl2 in mammals have remained elusive. Whole genome duplication in the teleost lineage generated the barhl1a and barhl2 paralogues. In the Zebrafish retina, Barhl2 functions as determinant of subsets of amacrine cells lineally related to RGCs independently of Atoh7. In contrast, barhl1a expression depends on Atoh7 but its expression dynamics and function have not been studied. Here we describe for the first time a Barhl1a:GFP reporter line in vivo showing that Barhl1a turns on exclusively in subsets of RGCs and their post-mitotic precursors. We also show transient expression of Barhl1a:GFP in diencephalic neurons extending their axonal projections as part of the post-optic commissure, at the time of optic chiasm formation. This work sets the ground for future studies on RGC subtype identity, axonal projections and genetic specification of Barhl1a-positive RGCs and commissural neurons.

Characterization of Spontaneous Inhibitory Synaptic Currents in Salamander Retinal Ganglion Cells

1998 ◽  
Vol 80 (4) ◽  
pp. 1752-1764 ◽  
Author(s):  
Fan Gao ◽  
Samuel M. Wu
Keyword(s):  
Retinal Ganglion Cells ◽  
Synaptic Vesicles ◽  
Ganglion Cells ◽  
Amacrine Cells ◽  
Equilibrium Potential ◽  
Retinal Ganglion ◽  
Light Onset ◽  
Synaptic Currents ◽  
Postsynaptic Currents

Gao, Fan and Samuel M. Wu. Characterization of spontaneous inhibitory synaptic currents in salamander retinal ganglion cells. J. Neurophysiol. 80: 1752–1764, 1998. Spontaneous and light-evoked postsynaptic currents (sPSCs and lePSCs, respectively) in retinal ganglion cells of the larval tiger salamander were recorded under voltage-clamp conditions from living retinal slices. The focus of this study is to characterize the spontaneous inhibitory PSCs (sIPSCs) and their contribution to the light-evoked inhibitory PSCs (leIPSCs) in on-off ganglion cells. sIPSCs were isolated from spontaneous excitatory PSCs (sEPSCs) by application of 10 μM 6,7-dinitroquinoxaline-2,3-dione (DNQX) + 50 μM 2-amino-5-phosphonopentanoic acid (AP5). In ∼70% of on-off ganglion cells, bicuculline (or picrotoxin) completely blocks sIPSCs, suggesting all sIPSCs in these cells are mediated by GABAergic synaptic vesicles and γ-aminobutyric acid-A (GABAA) receptors (GABAergic sIPSCs, or GABAsIPSCs). In the remaining 30% of on-off ganglion cells, bicuculline (or picrotoxin) blocks 70–98% of the sIPSCs, and the remaining 2–30% are blocked by strychnine (glycinergic sIPSCs, or GLYsIPSCs). GABAsIPSCs occur randomly with an exponentially distributed interval probability density function, and they persist without noticeable rundown over time. The GABAsIPSC frequency is greatly reduced by cobalt, consistent with the idea that they are largely mediated by calcium-dependent vesicular release. GABAsIPSCs in DNQX + AP5 are tetrodotoxin (TTX) insensitive, suggesting that amacrine cells that release GABA under these conditions do not generate spontaneous action potentials. The average GABAsIPSCs exhibited linear current-voltage relation with a reversal potential near the chloride equilibrium potential, and an average peak conductance of 319.67 ± 252.83 (SD) pS. For GLYsIPSCs, the average peak conductance increase is 301.68 ± 94.34 pS. These parameters are of the same order of magnitude as those measured in inhibitory miniature postsynaptic currents (mIPSCs) associated with single synaptic vesicles in the CNS. The amplitude histograms of GABAsIPSCs did not exhibit multiple peaks, suggesting that the larger events are not discrete multiples of elementary events (or quanta). We propose that each GABAsIPSC or GLYsIPSC in retinal ganglion cells is mediated by a single or synchronized multiple of synaptic vesicles with variable neurotransmitter contents. In a sample of 16 on-off ganglion cells, the average peak leIPSC (held at 0 mV) at the light onset is 509.0 ± 233.85 pA and that at the light offset is 529.0 ± 339.88 pA. The approximate number of GABAsIPSCs and GLYsIPSCs required to generate the average light responses, calculated by the ratio of the charge (area under current traces) of the leIPSCs to that of the average single sIPSCs, is 118 ± 52 for the light onset, and 132 ± 76 for the light offset.

A quantitative analysis of the effects of excitatory neurotoxins on retinal ganglion cells in the chick

1990 ◽  
Vol 4 (3) ◽  
pp. 217-223 ◽  
Author(s):  
Ngoh Ngoh Tung ◽  
Ian G. Morgan ◽  
David Ehrlich
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Amacrine Cells ◽  
Small Cells ◽  
Retinal Ganglion ◽  
Chick Retina ◽  
Area 5 ◽  
Different Types ◽  
Displaced Amacrine Cells ◽  
Series Of Experiments

AbstractThe present study examines the differential effects of three excitotoxins, kainic acid (KA), N-methyl-D-aspartate (NMDA), and α-amino-2,3-amino-2,3-dihydro-5- methyl-3-oxo-4- isoxazolepropanoic acid (AMPA) on neurons within the genglion cell layer (GCL) of the chick retina. Two-day-old chicks were given a single, 5 μl, intravitreal injection of KA, NMDA, or AMPA at a range of doses. Following treatment with 40 nmol KA, there was a 21% loss of neurons in the GCL. At 200 nmol KA, the loss increased to 46%. Exposure to KA eliminated mainly small neurons of soma area 5–15μm2, and medium-sized ganglion cells of soma area 15–25μm2. Large ganglion cells (>25μ,2) remained unaffected. The vast majority of small cells were probably displaced amarcrine cells. At a does of 3000 nmol NMDA, no further loss of cells was evident. Exposure to 200 nmol AMPA resulted in a 30% loss of large and some medium-sized ganglion cells. In a further series of experiments, exposure to excitotoxin was followed by a retinal scratch, which eliminated retinal ganglion cells within the axotomized region. The results indicate that only a small proportion of displaced amacrine cells are destroyed by NMDA and AMPA, whereas virtually all displaced amarine cells are sensitive to KA. The findings of this study indicate the existence of subclasses of ganglion cells with specificity towards different types of excitatory amino acids (EAA).

scholarly journals PTEN Expression Regulates Gap Junction Connectivity in the Retina

2021 ◽  
Vol 15 ◽  
Author(s):  
Ashley M. Chen ◽  
Shaghauyegh S. Azar ◽  
Alexander Harris ◽  
Nicholas C. Brecha ◽  
Luis Pérez de Sevilla Müller
Keyword(s):  
Gap Junction ◽  
Retinal Ganglion Cells ◽  
Vision Loss ◽  
Ganglion Cells ◽  
Dendritic Structure ◽  
Amacrine Cells ◽  
Mouse Retina ◽  
Retinal Ganglion ◽  
Cell Coupling ◽  
Cell Degeneration

Manipulation of the phosphatase and tensin homolog (PTEN) pathway has been suggested as a therapeutic approach to treat or prevent vision loss due to retinal disease. In this study, we investigated the effects of deleting one copy of Pten in a well-characterized class of retinal ganglion cells called α-ganglion cells in the mouse retina. In Pten+/– retinas, α-ganglion cells did not exhibit major changes in their dendritic structure, although most cells developed a few, unusual loop-forming dendrites. By contrast, α-ganglion cells exhibited a significant decrease in heterologous and homologous gap junction mediated cell coupling with other retinal ganglion and amacrine cells. Additionally, the majority of OFF α-ganglion cells (12/18 cells) formed novel coupling to displaced amacrine cells. The number of connexin36 puncta, the predominant connexin that mediates gap junction communication at electrical synapses, was decreased by at least 50% on OFF α-ganglion cells. Reduced and incorrect gap junction connectivity of α-ganglion cells will affect their functional properties and alter visual image processing in the retina. The anomalous connectivity of retinal ganglion cells would potentially limit future therapeutic approaches involving manipulation of the Pten pathway for treating ganglion cell degeneration in diseases like glaucoma, traumatic brain injury, Parkinson’s, and Alzheimer’s diseases.

scholarly journals Mouse dLGN receives input from a diverse population of retinal ganglion cells with limited convergence

2018 ◽  
Author(s):  
Miroslav Román Rosón ◽  
Yannik Bauer ◽  
Philipp Berens ◽  
Thomas Euler ◽  
Laura Busse
Keyword(s):  
Functional Connectivity ◽  
Retinal Ganglion Cells ◽  
Visual Processing ◽  
Visual Information ◽  
Ganglion Cells ◽  
Retinal Ganglion ◽  
Diverse Population ◽  
Relay Station ◽  
Functional Convergence ◽  
High Degree

SUMMARYIn the mouse, the parallel output of more than 30 functional types of retinal ganglion cells (RGCs) serves as the basis for all further visual processing. Little is known about how the representation of visual information changes between the retina and the dorsolateral geniculate nucleus (dLGN) of the thalamus, the main relay station between the retina and cortex. Here, we functionally characterized responses of retrogradely labeled dLGN-projecting RGCs and dLGN neurons to the same set of visual stimuli. We found that many of the previously identified functional RGC types innervate the dLGN, which maintained a high degree of functional diversity. Using a linear model to assess functional connectivity between RGC types and dLGN neurons, we found that the responses of dLGN neurons could be predicted as a linear combination of inputs from on average five RGC types, but only two of those had the strongest functional impact. Thus, mouse dLGN receives input from a diverse population of RGCs with limited functional convergence.

Disruption of transient photoreceptor targeting within the inner plexiform layer following early ablation of cholinergic amacrine cells in the ferret

2001 ◽  
Vol 18 (5) ◽  
pp. 741-751 ◽  
Author(s):  
P.T. JOHNSON ◽  
M.A. RAVEN ◽  
B.E. REESE
Keyword(s):  
Retinal Ganglion Cells ◽  
Amacrine Cell ◽  
Ganglion Cells ◽  
Plexiform Layer ◽  
Amacrine Cells ◽  
Inner Plexiform Layer ◽  
Retinal Ganglion ◽  
Subcutaneous Injections ◽  
Cell Processes ◽  
Cholinergic Amacrine Cells

Photoreceptors in the ferret's retina have been shown to project transiently to the inner plexiform layer (IPL) prior to their differentiation of an outer segment. On postnatal day 15 (P-15), when this projection achieves maximal density, the photoreceptors projecting into the IPL extend primarily to one of two depths, coincident with the processes of cholinergic amacrine cells. The present study has used an excitotoxic approach employing subcutaneous injections of l-glutamate to ablate these cholinergic amacrine cells on P-7, in order to see whether their elimination alters this targeting of photoreceptor terminals within the IPL. The near-complete elimination of cholinergic amacrine cells at P-15 was confirmed, although the population of retinal ganglion cells was also affected, being depleted by roughly 50%. The rod opsin-immunopositive terminals in such treated ferrets no longer showed a stratified distribution, being found throughout the depth of the IPL, as well as extending into the ganglion cell layer. This effect should not be due to the partial loss of retinal ganglion cells, however, since optic nerve transection at P-2, which eliminates the ganglion cells entirely while leaving the cholinergic amacrine cell population intact, was shown not to affect the stratification pattern of the photoreceptors within the IPL. These results strongly suggest that the targeting of the photoreceptor terminals to discrete strata within the IPL is dependent upon the cholinergic amacrine cell processes.

scholarly journals Synaptic inputs from identified bipolar and amacrine cells to a sparsely branched ganglion cell in rabbit retina

2019 ◽  
Vol 36 ◽  
Author(s):  
Andrea S. Bordt ◽  
Diego Perez ◽  
Luke Tseng ◽  
Weiley Sunny Liu ◽  
Jay Neitz ◽  
...  
Keyword(s):  
Ganglion Cell ◽  
Retinal Ganglion Cells ◽  
Amacrine Cell ◽  
Ganglion Cells ◽  
Amacrine Cells ◽  
Bipolar Cells ◽  
Rabbit Retina ◽  
Retinal Ganglion ◽  
Synaptic Inputs ◽  
Class Iv

AbstractThere are more than 30 distinct types of mammalian retinal ganglion cells, each sensitive to different features of the visual environment. In rabbit retina, they can be grouped into four classes according to their morphology and stratification of their dendrites in the inner plexiform layer (IPL). The goal of this study was to describe the synaptic inputs to one type of Class IV ganglion cell, the third member of the sparsely branched Class IV cells (SB3). One cell of this type was partially reconstructed in a retinal connectome developed using automated transmission electron microscopy (ATEM). It had slender, relatively straight dendrites that ramify in the sublamina a of the IPL. The dendrites of the SB3 cell were always postsynaptic in the IPL, supporting its identity as a ganglion cell. It received 29% of its input from bipolar cells, a value in the middle of the range for rabbit retinal ganglion cells studied previously. The SB3 cell typically received only one synapse per bipolar cell from multiple types of presumed OFF bipolar cells; reciprocal synapses from amacrine cells at the dyad synapses were infrequent. In a few instances, the bipolar cells presynaptic to the SB3 ganglion cell also provided input to an amacrine cell presynaptic to the ganglion cell. There was apparently no crossover inhibition from narrow-field ON amacrine cells. Most of the amacrine cell inputs were from axons and dendrites of GABAergic amacrine cells, likely providing inhibitory input from outside the classical receptive field.

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