scholarly journals Cellular positioning and dendritic field size of cholinergic amacrine cells are impervious to early ablation of neighboring cells in the mouse retina

2004 ◽  
Vol 21 (1) ◽  
pp. 13-22 ◽  
Author(s):  
REZA FARAJIAN ◽  
MARY A. RAVEN ◽  
KAREN CUSATO ◽  
BENJAMIN E. REESE
Keyword(s):  
Lucifer Yellow ◽  
Single Cells ◽  
Amacrine Cells ◽  
Field Size ◽  
Mouse Retina ◽  
Dendritic Field ◽  
Normal Retina ◽  
Field Area ◽  
Cholinergic Amacrine Cells ◽  
Neighbor Relationships

We have examined the role of neighbor relationships between cholinergic amacrine cells upon their positioning and dendritic field size by producing partial ablations of this population of cells during early development. We first determined the effectiveness ofl-glutamate as an excitotoxin for ablating cholinergic amacrine cells in the developing mouse retina. Subcutaneous injections (4 mg/g) made on P-3 and thereafter were found to produce a near-complete elimination, while injections at P-2 were ineffective. Lower doses on P-3 produced only partial reductions, and were subsequently used to examine the effect of partial ablation upon mosaic organization and dendritic growth of the remaining cells. Four different Voronoi-based measures of mosaic geometry were examined inl-glutamate-treated and normal (saline-treated) retinas. Partial depletions of around 40% produced cholinergic mosaics that, when scaled for density, approximated the mosaic geometry of the normal retina. Separate comparisons simulating a 40% random deletion of the normal retina produced mosaics that were no different from those experimentally depleted retinas. Consequently, no evidence was found for positional regulation in the absence of normal neighbor relationships. Single cells in the ganglion cell layer were intracellularly filled with Lucifer Yellow to examine the morphology and dendritic field extent following partial ablation of the cholinergic amacrine cells. No discernable effect was found on their starburst morphology, and total dendritic field area, number of primary dendrites, and branch frequency were not significantly different. Cholinergic amacrine cells normally increase their dendritic field area after P-3 in excess of retinal expansion; despite this, the present results show that this growth is not controlled by the density of neighboring processes.

A coupled network for parasol but not midget ganglion cells in the primate retina

1992 ◽  
Vol 9 (3-4) ◽  
pp. 279-290 ◽  
Author(s):  
Dennis M. Dacey ◽  
Sarah Brace
Keyword(s):  
Nearest Neighbor ◽  
Ganglion Cells ◽  
Plexiform Layer ◽  
Amacrine Cells ◽  
Cell Types ◽  
Distinct Pattern ◽  
Field Size ◽  
Inner Plexiform Layer ◽  
Dendritic Field

AbstractIntracellular injections of Neurobiotin were used to determine whether the major ganglion cell classes of the macaque monkey retina, the magnocellular-projecting parasol, and the parvocellular-projecting midget cells showed evidence of cellular coupling similar to that recently described for cat retinal ganglion cells. Ganglion cells were labeled with the fluorescent dye acridine orange in an in vitro, isolated retina preparation and were selectively targeted for intracellular injection under direct microscopic control. The macaque midget cells, like the beta cells of the cat's retina, showed no evidence of tracer coupling when injected with Neurobiotin. By contrast, Neurobiotin-filled parasol cells, like cat alpha cells, showed a distinct pattern of tracer coupling to each other (homotypic coupling) and to amacrine cells (heterotypic coupling).In instances of homotypic coupling, the injected parasol cell was surrounded by a regular array of 3–6 neighboring parasol cells. The somata and proximal dendrites of these tracer-coupled cells were lightly labeled and appeared to costratify with the injected cell. Analysis of the nearest-neighbor distances for the parasol cell clusters showed that dendritic-field overlap remained constant as dendritic-field size increased from 100–400 μm in diameter.At least two amacrine cell types showed tracer coupling to parasol cells. One amacrine type had a small soma and thin, sparsely branching dendrites that extended for 1–2 mm in the inner plexiform layer. A second amacrine type had a relatively large soma, thick main dendrites, and distinct, axon-like processes that extended for at least 2–3 mm in the inner plexiform layer. The main dendrites of the large amacrine cells were closely apposed to the dendrites of parasol cells and may be the site of Neurobiotin transfer between the two cell types. We suggest that the tracer coupling between neighboring parasol cells takes place indirectly via the dendrites of the large amacrine cells and provides a mechanism, absent in midget cells, for increasing parasol cell receptive-field size and luminance contrast sensitivity.

The type 1 polyaxonal amacrine cells of the rabbit retina: A tracer-coupling study

2004 ◽  
Vol 21 (2) ◽  
pp. 145-155 ◽  
Author(s):  
LAYNE L. WRIGHT ◽  
DAVID I. VANEY
Keyword(s):  
Dendritic Tree ◽  
Plexiform Layer ◽  
Amacrine Cells ◽  
Field Size ◽  
Equivalent Diameter ◽  
Inner Plexiform Layer ◽  
Rabbit Retina ◽  
Visual Streak ◽  
Field Area

The type 1 polyaxonal (PA1) cell is a distinct type of axon-bearing amacrine cell whose soma commonly occupies an interstitial position in the inner plexiform layer; the proximal branches of the sparse dendritic tree produce 1–4 axon-like processes, which form an extensive axonal arbor that is concentric with the smaller dendritic tree (Dacey, 1989; Famiglietti, 1992a,b). In this study, intracellular injections of Neurobiotin have revealed the complete dendritic and axonal morphology of the PA1 cells in the rabbit retina, as well as labeling the local array of PA1 cells through homologous tracer coupling. The dendritic-field area of the PA1 cells increased from a minimum of 0.15 mm2 (0.44-mm equivalent diameter) on the visual streak to a maximum of 0.67 mm2 (0.92-mm diameter) in the far periphery; the axonal-field area also showed a 3-fold variation across the retina, ranging from 3.1 mm2 (2.0-mm diameter) to 10.2 mm2 (3.6-mm diameter). The increase in dendritic- and axonal-field size was accompanied by a reduction in cell density, from 60 cells/mm2 in the visual streak to 20 cells/mm2 in the far periphery, so that the PA1 cells showed a 12 times overlap of their dendritic fields across the retina and a 200–300 times overlap of their axonal fields. Consequently, the axonal plexus was much denser than the dendritic plexus, with each square millimeter of retina containing ∼100 mm of dendrites and ∼1000 mm of axonal processes. The strong homologous tracer coupling revealed that ∼45% of the PA1 somata were located in the inner nuclear layer, ∼50% in the inner plexiform layer, and ∼5% in the ganglion cell layer. In addition, the Neurobiotin-injected PA1 cells sometimes showed clear heterologous tracer coupling to a regular array of small ganglion cells, which were present at half the density of the PA1 cells. The PA1 cells were also shown to contain elevated levels of γ-aminobutyric acid (GABA), like other axon-bearing amacrine cells.

scholarly journals Spatial patterning of cholinergic amacrine cells in the mouse retina

2008 ◽  
Vol 508 (2) ◽  
pp. SPC1-SPC1
Author(s):  
Irene E. Whitney ◽  
Patrick W. Keeley ◽  
Mary A. Raven ◽  
Benjamin E. Reese
Keyword(s):  
Amacrine Cells ◽  
Mouse Retina ◽  
Spatial Patterning ◽  
Cholinergic Amacrine Cells

scholarly journals Spatial patterning of cholinergic amacrine cells in the mouse retina

2008 ◽  
Vol 508 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Irene E. Whitney ◽  
Patrick W. Keeley ◽  
Mary A. Raven ◽  
Benjamin E. Reese
Keyword(s):  
Amacrine Cells ◽  
Mouse Retina ◽  
Spatial Patterning ◽  
Cholinergic Amacrine Cells

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.

Characterization of Voltage-Gated Ionic Channels in Cholinergic Amacrine Cells in the Mouse Retina

2007 ◽  
Vol 97 (6) ◽  
pp. 4225-4234 ◽  
Author(s):  
Makoto Kaneda ◽  
Koichi Ito ◽  
Yosuke Morishima ◽  
Yasuhide Shigematsu ◽  
Yukio Shimoda
Keyword(s):  
Amacrine Cells ◽  
Ionic Channels ◽  
Signal Propagation ◽  
Membrane Properties ◽  
Mouse Retina ◽  
Delayed Rectifier ◽  
Ca Channel ◽  
Voltage Gated ◽  
A Current ◽  
Cholinergic Amacrine Cells

Recent studies have shown that cholinergic amacrine cells possess unique membrane properties. However, voltage-gated ionic channels in cholinergic amacrine cells have not been characterized systematically. In this study, using electrophysiological and immunohistochemical techniques, we examined voltage-gated ionic channels in a transgenic mouse line the cholinergic amacrine cells of which were selectively labeled with green fluorescent protein (GFP). Voltage-gated K+ currents contained a 4-aminopyridine-sensitive current (A current) and a tetraethylammonium-sensitive current (delayed rectifier K+ current). Voltage-gated Ca2+ currents contained a ω-conotoxin GVIA-sensitive component (N-type) and a ω-Aga IVA-sensitive component (P/Q-type). Tetrodotoxin-sensitive Na+ currents and dihydropyridine-sensitive Ca2+ currents (L-type) were not observed. Immunoreactivity for the Na channel subunit (Pan Nav), the K channel subunits (the A-current subunits [Kv. 3.3 and Kv 3.4]) and the Ca channel subunits (α1A [P/Q-type], α1B [N-type] and α1C [L-type]) was detected in the membrane fraction of the mouse retina by Western blot analysis. Immunoreactivity for the Kv. 3.3, Kv 3.4, α1A [P/Q-type], and α1B [N-type] was colocalized with the GFP signals. Immunoreactivity for α1C [L-type] was not colocalized with the GFP signals. Immunoreactivity for Pan Nav did not exist on the membrane surface of the GFP-positive cells. Our findings indicate that signal propagation in cholinergic amacrine cells is mediated by a combination of two types of voltage-gated K+ currents (the A current and the delayed rectifier K+ current) and two types of voltage-gated Ca2+ currents (the P/Q-type and the N-type) in the mouse retina.

Relationship between receptive and dendritic field size of amacrine cells in the rabbit retina

1992 ◽  
Vol 68 (3) ◽  
pp. 711-725 ◽  
Author(s):  
S. A. Bloomfield
Keyword(s):  
Receptive Field ◽  
Action Potentials ◽  
Total Population ◽  
Receptive Fields ◽  
Amacrine Cells ◽  
Dendritic Morphology ◽  
Field Size ◽  
Dendritic Arbor ◽  
Dendritic Field ◽  
Synaptic Inputs

1. Intracellular recordings were obtained from 40 amacrine cells in the isolated, superfused retina eyecup of the rabbit. Cells were subsequently labeled with horseradish peroxidase for morphological identification. Many of these cells displayed dendritic morphology consistent with that of amacrine cells described in prior anatomic studies, including starburst, A17, AII, and DAPI-3 cells. 2. The center receptive field of amacrine cells was measured with a 50- or 95-microns-wide, 6.0-mm-long rectangular slit of light that was displaced along its minor axis (parallel to the visual streak) in increments as small as 3 microns. The extent of the receptive field was calculated as the total distance over which the displaced slit could evoke a center response. Area summation of amacrine cells was measured with concentric spots of light with increasing diameters centered over the cell. 3. For a single amacrine cell, the receptive field size was comparable to the extent of its dendritic arbor. For the total population of amacrine cells, there was a strong, linear relationship between receptive field and dendritic field size. The receptive fields were, on average, 27% larger than the corresponding dendritic arbors, but this discrepancy can be accounted for entirely by tissue shrinkage associated with histological processing and a small imprecision of the light stimuli. Area summation measurements were consistent with those of receptive fields and were also related linearly to the dendritic field size of cells. 4. These findings indicate that even when the slit of light was placed at the distal edges of the dendritic arbor, synaptic inputs activated there were propagated effectively to the soma and recorded by microelectrodes placed there. In addition, amacrine cells were capable of summating synaptic inputs distributed throughout the entire arbor. 5. These results are inconsistent with the findings of prior computational modeling studies of passive, dendritic current flow in A17 and starburst amacrine cells that synaptic inputs on distal dendritic branches are isolated electrically from the soma and that these branches form autonomous, functional subunits. 6. The majority of amacrine cells encountered displayed light-evoked and/or spontaneous action potentials. These action potentials often took the form of high-amplitude somatic and low-amplitude dendritic spikes. On average, spiking amacrine cells showed considerably larger dendritic fields than nonspiking amacrine cells. In fact, all amacrine cells with arbors greater than 436 microns, which formed 45% of the total population, displayed spike activity.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Novel channel-mediated choline transport in cholinergic neurons of the mouse retina

2017 ◽  
Vol 118 (4) ◽  
pp. 1952-1961 ◽  
Author(s):  
Toshiyuki Ishii ◽  
Kohei Homma ◽  
Asuka Mano ◽  
Takumi Akagi ◽  
Yasuhide Shigematsu ◽  
...  
Keyword(s):  
Purinergic Receptors ◽  
Expression System ◽  
Cholinergic Neurons ◽  
Amacrine Cells ◽  
Mouse Retina ◽  
Choline Uptake ◽  
Transport Pathway ◽  
Choline Transport ◽  
High Affinity ◽  
Cholinergic Amacrine Cells

Choline uptake into the presynaptic terminal of cholinergic neurons is mediated by the high-affinity choline transporter and is essential for acetylcholine synthesis. In a previous study, we reported that P2X2 purinoceptors are selectively expressed in OFF-cholinergic amacrine cells of the mouse retina. Under specific conditions, P2X2 purinoceptors acquire permeability to large cations, such as N-methyl-d-glucamine, and therefore potentially could act as a noncanonical pathway for choline entry into neurons. We tested this hypothesis in OFF-cholinergic amacrine cells of the mouse retina. ATP-induced choline currents were observed in OFF-cholinergic amacrine cells, but not in ON-cholinergic amacrine cells, in mouse retinal slice preparations. High-affinity choline transporters are expressed at higher levels in ON-cholinergic amacrine cells than in OFF-cholinergic amacrine cells. In dissociated preparations of cholinergic amacrine cells, ATP-activated cation currents arose from permeation of extracellular choline. We also examined the pharmacological properties of choline currents. Pharmacologically, α,β-methylene ATP did not produce a cation current, whereas ATPγS and benzoyl-benzoyl-ATP (BzATP) activated choline currents. However, the amplitude of the choline current activated by BzATP was very small. The choline current activated by ATP was strongly inhibited by pyridoxalphosphate-6-azophenyl-2′,4′-sulfonic acid. Accordingly, P2X2 purinoceptors expressed in HEK-293T cells were permeable to choline and similarly functioned as a choline uptake pathway. Our physiological and pharmacological findings support the hypothesis that P2 purinoceptors, including P2X2 purinoceptors, function as a novel choline transport pathway and may provide a new regulatory mechanism for cholinergic signaling transmission at synapses in OFF-cholinergic amacrine cells of the mouse retina. NEW & NOTEWORTHY Choline transport across the membrane is exerted by both the high-affinity and low-affinity choline transporters. We found that choline can permeate P2 purinergic receptors, including P2X2 purinoceptors, in cholinergic neurons of the retina. Our findings show the presence of a novel choline transport pathway in cholinergic neurons. Our findings also indicate that the permeability of P2X2 purinergic receptors to choline observed in the heterologous expression system may have a physiological relevance in vivo.

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