scholarly journals Regulation of retinal amacrine cell generation by miR-216b and Foxn3

2020 ◽  
Author(s):  
Huanqing Zhang ◽  
Pei Zhuang ◽  
Ryan M. Welchko ◽  
Manhong Dai ◽  
Fan Meng ◽  
...  
Keyword(s):  
Amacrine Cell ◽  
Ectopic Expression ◽  
Cell Formation ◽  
Complex Mixture ◽  
Amacrine Cells ◽  
Retinal Cell ◽  
Mouse Retina ◽  
Mammalian Retina ◽  
Different Types ◽  
Retinal Explants

AbstractThe mammalian retina contains a complex mixture of different types of neurons. We find that the microRNA miR-216b is preferentially expressed in postmitotic retinal amacrine cells in the mouse retina, and expression of miR-216a/b and miR-217 in the retina depend in part on Ptf1a, a transcription factor required for amacrine cell differentiation. Surprisingly, ectopic expression of miR-216b, or the related miR-216a, can direct the formation of additional amacrine cells in the developing retina. In addition, we observe the loss of bipolar neurons in the retina after miR-216b expression. We identify the mRNA for the transcriptional regulator Foxn3 as a retinal target of miR-216b by Argonaute PAR-CLIP and reporter analysis. Inhibition of Foxn3 in the postnatal developing retina by RNAi also increases the formation of amacrine cells and reduces bipolar cell formation, while overexpression of Foxn3 inhibits amacrine cell formation prior to the expression of Ptf1a. Disruption of Foxn3 by CRISPR in embryonic retinal explants also reduces amacrine cell formation. Co-expression of Foxn3 can partially reverse the effects of ectopic miR-216b on retinal cell type formation. Our results identify Foxn3 as a novel regulator of interneuron formation in the developing retina and suggest that miR-216b likely regulates expression of Foxn3 and other genes in amacrine cells.

scholarly journals Regulation of retinal amacrine cell generation by miR-216b and Foxn3

Development ◽  
2021 ◽  
Author(s):  
Huanqing Zhang ◽  
Pei Zhuang ◽  
Ryan M. Welchko ◽  
Manhong Dai ◽  
Fan Meng ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Amacrine Cell ◽  
Ectopic Expression ◽  
Cell Formation ◽  
Complex Mixture ◽  
Amacrine Cells ◽  
Retinal Cell ◽  
Mouse Retina ◽  
Different Types ◽  
Retinal Explants

The mammalian retina contains a complex mixture of different types of neurons. We find that microRNA miR-216b is preferentially expressed in postmitotic retinal amacrine cells in the mouse retina, and expression of miR-216a/b and miR-217 in retina depend in part on Ptf1a, a transcription factor required for amacrine cell differentiation. Surprisingly, ectopic expression of miR-216b directed the formation of additional amacrine cells and reduced bipolar neurons in the developing retina. We identify the Foxn3 mRNA as a retinal target of miR-216b by Argonaute PAR-CLIP and reporter analysis. Inhibition of Foxn3, a transcription factor, in the postnatal developing retina by RNAi increased the formation of amacrine cells and reduced bipolar cell formation. Foxn3 disruption by CRISPR in embryonic retinal explants also increased amacrine cell formation, while Foxn3 overexpression inhibited amacrine cell formation prior to Ptf1a expression. Co-expression of Foxn3 partially reversed the effects of ectopic miR-216b on retinal cell formation. Our results identify Foxn3 as a novel regulator of interneuron formation in the developing retina and suggest that miR-216b likely regulates Foxn3 and other genes in amacrine cells.

scholarly journals A high-density narrow-field inhibitory retinal interneuron with direct coupling to Müller glia

2020 ◽  
Author(s):  
William N Grimes ◽  
Didem Göz Aytürk ◽  
Mrinalini Hoon ◽  
Takeshi Yoshimatsu ◽  
Clare Gamlin ◽  
...  
Keyword(s):  
Gap Junctions ◽  
Glial Cells ◽  
Amacrine Cell ◽  
Electrical Coupling ◽  
Amacrine Cells ◽  
Muller Glia ◽  
Müller Glia ◽  
Cell Type ◽  
Mammalian Retina ◽  
Ganglion Neurons

AbstractAmacrine cells are interneurons comprising the most diverse cell type in the mammalian retina. They help encode visual features such as edges or directed motion by mediating excitatory and inhibitory interactions between input (i.e. bipolar) and output (i.e. ganglion) neurons in the inner plexiform layer (IPL). Like other brain regions, the retina also contains glial cells that contribute to neurotransmitter uptake, neurovascular control and metabolic regulation. Here, we report that a previously poorly characterized, but relatively abundant, inhibitory amacrine cell type in the mouse retina is coupled directly to Müller glia. Electron microscopic reconstructions of this amacrine type revealed extensive associations with Müller glia, whose processes often completely ensheathe the neurites of this amacrine cell type. Microinjections of small tracer molecules into the somas of these amacrine cells led to selective labelling of nearby Müller glia, leading us to suggest the name “Müller glia-coupled amacrine cell” or MAC. Our electrophysiological data also indicate that MACs release glycine at conventional chemical synapses with amacrine, bipolar and retinal ganglion cells (RGCs), and viral transsynaptic tracing showed connections to several known RGC types. Visually-evoked responses revealed a strong preference for light increments; these “ON” responses were primarily mediated by excitatory chemical synaptic input and direct electrical coupling to other cells. This initial characterization of the MAC provides the first evidence for neuron-glia coupling in the mammalian retina and identifies the MAC as a potential link between inhibitory processing and glial function.Significance StatementGap junctions between pairs of neurons or glial cells are commonly found throughout the nervous system, and play a myriad of roles including electrical coupling and metabolic exchange. In contrast, gap junctions between neurons and glia cells are rare and poorly understood. Here we report the first evidence for neuron-glia coupling in the mammalian retina, specifically between an abundant (but previously unstudied) inhibitory interneuron and Müller glia.

scholarly journals Molecular identification of sixty-three amacrine cell types completes a mouse retinal cell atlas

2020 ◽  
Author(s):  
Wenjun Yan ◽  
Mallory A. Laboulaye ◽  
Nicholas M. Tran ◽  
Irene E. Whitney ◽  
Inbal Benhar ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Single Cell ◽  
High Throughput ◽  
Amacrine Cells ◽  
Cell Types ◽  
Retinal Cell ◽  
Mouse Retina ◽  
Single Cell Rna Sequencing ◽  
Neuronal Types ◽  
The Brain

ABSTRACTAmacrine cells (ACs) are a diverse class of interneurons that modulate input from photoreceptors to retinal ganglion cells (RGCs), rendering each RGC type selectively sensitive to particular visual features, which are then relayed to the brain. While many AC types have been identified morphologically and physiologically, they have not been comprehensively classified or molecularly characterized. We used high-throughput single-cell RNA sequencing (scRNA-seq) to profile >32,000 ACs from mouse retina, and applied computational methods to identify 63 AC types. We identified molecular markers for each type, and used them to characterize the morphology of multiple types. We show that they include nearly all previously known AC types as well as many that had not been described. Consistent with previous studies, most of the AC types express markers for the canonical inhibitory neurotransmitters GABA or glycine, but several express neither or both. In addition, many express one or more neuropeptides, and two express glutamatergic markers. We also explored transcriptomic relationships among AC types and identified transcription factors expressed by individual or multiple closely related types. Noteworthy among these were Meis2 and Tcf4, expressed by most GABAergic and most glycinergic types, respectively. Together, these results provide a foundation for developmental and functional studies of ACs, as well as means for genetically accessing them. Along with previous molecular, physiological and morphological analyses, they establish the existence of at least 130 neuronal types and nearly 140 cell types in mouse retina.SIGNIFICANCE STATEMENTThe mouse retina is a leading model for analyzing the development, structure, function and pathology of neural circuits. A complete molecular atlas of retinal cell types provides an important foundation for these studies. We used high-throughput single-cell RNA sequencing (scRNA-seq) to characterize the most heterogeneous class of retinal interneurons, amacrine cells, identifying 63 distinct types. The atlas includes types identified previously as well as many novel types. We provide evidence for use of multiple neurotransmitters and neuropeptides and identify transcription factors expressed by groups of closely related types. Combining these results with those obtained previously, we proposed that the mouse retina contains 130 neuronal types, and is therefore comparable in complexity to other regions of the brain.

scholarly journals Cross-synaptic synchrony and transmission of signal and noise across the mouse retina

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
William N Grimes ◽  
Mrinalini Hoon ◽  
Kevin L Briggman ◽  
Rachel O Wong ◽  
Fred Rieke
Keyword(s):  
Single Neuron ◽  
Amacrine Cells ◽  
Light Level ◽  
Bipolar Cells ◽  
Mouse Retina ◽  
Anatomical Connectivity ◽  
Physiological Conditions ◽  
Synaptic Noise ◽  
Mammalian Retina ◽  
Rod Bipolar Cells

Cross-synaptic synchrony—correlations in transmitter release across output synapses of a single neuron—is a key determinant of how signal and noise traverse neural circuits. The anatomical connectivity between rod bipolar and A17 amacrine cells in the mammalian retina, specifically that neighboring A17s often receive input from many of the same rod bipolar cells, provides a rare technical opportunity to measure cross-synaptic synchrony under physiological conditions. This approach reveals that synchronization of rod bipolar cell synapses is near perfect in the dark and decreases with increasing light level. Strong synaptic synchronization in the dark minimizes intrinsic synaptic noise and allows rod bipolar cells to faithfully transmit upstream signal and noise to downstream neurons. Desynchronization in steady light lowers the sensitivity of the rod bipolar output to upstream voltage fluctuations. This work reveals how cross-synaptic synchrony shapes retinal responses to physiological light inputs and, more generally, signaling in complex neural networks.

scholarly journals The LIM protein complex establishes a retinal circuitry of visual adaptation by regulating Pax6 α-enhancer activity

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Yeha Kim ◽  
Soyeon Lim ◽  
Taejeong Ha ◽  
You-Hyang Song ◽  
Young-In Sohn ◽  
...  
Keyword(s):  
Protein Complex ◽  
Transforming Growth Factor ◽  
Amacrine Cell ◽  
Amacrine Cells ◽  
Visual Adaptation ◽  
Mouse Retina ◽  
Visual Responses ◽  
Enhancer Activity ◽  
Lim Protein ◽  
Retinal Circuitry

The visual responses of vertebrates are sensitive to the overall composition of retinal interneurons including amacrine cells, which tune the activity of the retinal circuitry. The expression of Paired-homeobox 6 (PAX6) is regulated by multiple cis-DNA elements including the intronic α-enhancer, which is active in GABAergic amacrine cell subsets. Here, we report that the transforming growth factor ß1-induced transcript 1 protein (Tgfb1i1) interacts with the LIM domain transcription factors Lhx3 and Isl1 to inhibit the α-enhancer in the post-natal mouse retina. Tgfb1i1-/- mice show elevated α-enhancer activity leading to overproduction of Pax6ΔPD isoform that supports the GABAergic amacrine cell fate maintenance. Consequently, the Tgfb1i1-/- mouse retinas show a sustained light response, which becomes more transient in mice with the auto-stimulation-defective Pax6ΔPBS/ΔPBS mutation. Together, we show the antagonistic regulation of the α-enhancer activity by Pax6 and the LIM protein complex is necessary for the establishment of an inner retinal circuitry, which controls visual adaptation.

scholarly journals Ionotropic glutamate receptors of amacrine cells of the mouse retina

2006 ◽  
Vol 23 (1) ◽  
pp. 79-90 ◽  
Author(s):  
OLIVIA N. DUMITRESCU ◽  
DARIO A. PROTTI ◽  
SRIPARNA MAJUMDAR ◽  
HANNS ULRICH ZEILHOFER ◽  
HEINZ WÄSSLE
Keyword(s):  
Nmda Receptors ◽  
Glutamate Receptors ◽  
Amacrine Cell ◽  
Fluorescent Protein ◽  
Lucifer Yellow ◽  
Amacrine Cells ◽  
Ionotropic Glutamate Receptors ◽  
Mouse Retina ◽  
Wide Field ◽  
Transgenic Mouse Line

The mammalian retina contains approximately 30 different morphological types of amacrine cells, receiving glutamatergic input from bipolar cells. In this study, we combined electrophysiological and pharmacological techniques in order to study the glutamate receptors expressed by different types of amacrine cells. Whole-cell currents were recorded from amacrine cells in vertical slices of the mouse retina. During the recordings the cells were filled with Lucifer Yellow/Neurobiotin allowing classification as wide-field or narrow-field amacrine cells. Amacrine cell recordings were also carried out in a transgenic mouse line whose glycinergic amacrine cells express enhanced green fluorescent protein (EGFP). Agonist-induced currents were elicited by exogenous application of NMDA, AMPA, and kainate (KA) while holding cells at −75 mV. Using a variety of specific agonists and antagonists (NBQX, AP5, cyclothiazide, GYKI 52466, GYKI 53655, SYM 2081) responses mediated by AMPA, KA, and NMDA receptors could be dissected. All cells (n= 300) showed prominent responses to non-NMDA agonists. Some cells expressed AMPA receptors exclusively and some cells expressed KA receptors exclusively. In the majority of cells both receptor types could be identified. NMDA receptors were observed in about 75% of the wide-field amacrine cells and in less than half of the narrow-field amacrine cells. Our results confirm that different amacrine cell types express distinct sets of ionotropic glutamate receptors, which may be critical in conferring their unique temporal responses to this diverse neuronal class.

scholarly journals POU6F2 Positive Retinal Ganglion Cells a Novel Group of ON-OFF Directionally Selective Subtypes in the Mouse Retina

2020 ◽  
Author(s):  
Ying Li ◽  
Jiaxing Wang ◽  
Rebecca King ◽  
Eldon E. Geisert
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Yellow Fluorescent Protein ◽  
Corneal Thickness ◽  
Amacrine Cells ◽  
Molecular Signature ◽  
Retinal Cell ◽  
Mouse Retina ◽  
Inner Plexiform Layer ◽  
Retinal Ganglion

AbstractPurposePreviously we identified POU6F2 as a genetic link between central corneal thickness (CCT) and risk of open-angle glaucoma. The present study is designed to characterize the POU6F2-positive retinal ganglion cells (RGCs).MethodsThe Thy1-YFP-H mouse was used to identify the structure of POU6F2-positive RGCs in the retina. In the retina of the Thy1-YFP-H mouse approximately 3% of the RGCs were labeled with yellow fluorescent protein. These retinas were stained for POU6F2 to identify the morphology of the POU6F2 subtypes in 3D reconstructions of the labeled RGCs. Multiple retinal cell markers were also co-stained with POU6F2 to characterize the molecular signature of the POU6F2-positive RGCs. DBA/2J glaucoma models were used to test the role of POU6F2 in injury.ResultsIn the retina POU6F2 labels 32.9% of the RGCs in the DBA/2J retina (16.1% heavily and 16.8% lightly labeled). In 3D constructions of Thy1-YFP-H positive RGCs, the heavily labeled POU6F2-positive cells had dendrites in the inner plexiform layer that were bistratified and appeared to be ON-OFF directionally selective cells. The lightly labeled POU6F2 RGCs displayed 3 different dendritic distributions, with dendrites in the ON sublaminae only, OFF sublaminae only, or bistratified. The POU6F2-positive cells partially co-stained with Cdh6. The POU6F2-positive cells do not co-stain with CART and SATB2 (markers for ON-OFF directionally selective RGC), SMI32 (a marker for alpha RGCs), or ChAT and GAD67(markers for amacrine cells). The POU6F2-positive cells were sensitive to injury. In DBA/2J glaucoma model, at 8 months of age there was a 22% loss of RGCs (labeled with RBPMS) while there was 73% loss of the heavily labeled POU6F2 RGCs.ConclusionsPOU6F2 is a marker for a novel group of RGC subtypes that are ON-OFF directionally selective RGCs that are sensitive to glaucomatous injury.

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.

scholarly journals Intrinsic bursting of AII amacrine cells underlies oscillations in the rd1 mouse retina

2014 ◽  
Vol 112 (6) ◽  
pp. 1491-1504 ◽  
Author(s):  
Hannah Choi ◽  
Lei Zhang ◽  
Mark S. Cembrowski ◽  
Carl F. Sabottke ◽  
Alexander L. Markowitz ◽  
...  
Keyword(s):  
Amacrine Cell ◽  
Ganglion Cells ◽  
Wild Type Mouse ◽  
Amacrine Cells ◽  
Bipolar Cells ◽  
Membrane Properties ◽  
Mouse Retina ◽  
Intrinsic Membrane Properties ◽  
Rd1 Mouse ◽  
Aii Amacrine

In many forms of retinal degeneration, photoreceptors die but inner retinal circuits remain intact. In the rd1 mouse, an established model for blinding retinal diseases, spontaneous activity in the coupled network of AII amacrine and ON cone bipolar cells leads to rhythmic bursting of ganglion cells. Since such activity could impair retinal and/or cortical responses to restored photoreceptor function, understanding its nature is important for developing treatments of retinal pathologies. Here we analyzed a compartmental model of the wild-type mouse AII amacrine cell to predict that the cell's intrinsic membrane properties, specifically, interacting fast Na and slow, M-type K conductances, would allow its membrane potential to oscillate when light-evoked excitatory synaptic inputs were withdrawn following photoreceptor degeneration. We tested and confirmed this hypothesis experimentally by recording from AIIs in a slice preparation of rd1 retina. Additionally, recordings from ganglion cells in a whole mount preparation of rd1 retina demonstrated that activity in AIIs was propagated unchanged to elicit bursts of action potentials in ganglion cells. We conclude that oscillations are not an emergent property of a degenerated retinal network. Rather, they arise largely from the intrinsic properties of a single retinal interneuron, the AII amacrine cell.

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