scholarly journals Surround inhibition of mammalian AII amacrine cells is generated in the proximal retina

2000 ◽  
Vol 523 (3) ◽  
pp. 771-783 ◽  
Author(s):  
Stewart A. Bloomfield ◽  
Daiyan Xin
Keyword(s):  
Amacrine Cells ◽  
Surround Inhibition ◽  
Aii Amacrine Cells ◽  
Aii Amacrine

scholarly journals AII amacrine cells discriminate between heterocellular and homocellular locations when assembling connexin36-containing gap junctions

2014 ◽  
Vol 127 (6) ◽  
pp. 1190-1202 ◽  
Author(s):  
A. Meyer ◽  
G. Hilgen ◽  
B. Dorgau ◽  
E. M. Sammler ◽  
R. Weiler ◽  
...  
Keyword(s):  
Gap Junctions ◽  
Amacrine Cells ◽  
Aii Amacrine Cells ◽  
Aii Amacrine

Meclofenamic Acid Blocks Electrical Synapses of Retinal AII Amacrine and on-Cone Bipolar Cells

2009 ◽  
Vol 101 (5) ◽  
pp. 2339-2347 ◽  
Author(s):  
Margaret Lin Veruki ◽  
Espen Hartveit
Keyword(s):  
Amacrine Cells ◽  
Bipolar Cells ◽  
Electrical Synapse ◽  
Dependent Manner ◽  
Electrical Synapses ◽  
Meclofenamic Acid ◽  
Aii Amacrine Cells ◽  
Rod Pathway ◽  
Aii Amacrine ◽  
Cone Bipolar Cells

Gap junction channels constitute specialized intercellular contacts that can serve as electrical synapses. In the rod pathway of the retina, electrical synapses between AII amacrine cells express connexin 36 (Cx36) and electrical synapses between AII amacrines and on-cone bipolar cells express Cx36 on the amacrine side and Cx36 or Cx45 on the bipolar side. For physiological investigations of the properties and functions of these electrical synapses, it is highly desirable to have access to potent pharmacological blockers with selective and reversible action. Here we use dual whole cell voltage-clamp recordings of pairs of AII amacrine cells and pairs of AII amacrine and on-cone bipolar cells in rat retinal slices to directly measure the junctional conductance ( Gj) between electrically coupled cells and to study the effect of the drug meclofenamic acid (MFA) on Gj. Consistent with previous tracer coupling studies, we found that MFA reversibly blocked the electrical synapse currents in a concentration-dependent manner, with complete block at 100 μM. Whereas MFA evoked a detectable decrease in Gj within minutes of application, the time to complete block of Gj was considerably longer, typically 20–40 min. After washout, Gj recovered to 20–90% of the control level, but the time to maximum recovery was typically >1 h. These results suggest that MFA can be a useful drug to investigate the physiological functions of electrical synapses in the rod pathway, but that the slow kinetics of block and reversal might compromise interpretation of the results and that explicit monitoring of Gj is desirable.

scholarly journals Spikelets and bursts in axonless retinal AII amacrine cells coupled by gap junctions

2013 ◽  
Vol 14 (S1) ◽  
Author(s):  
Hermann Riecke ◽  
Hannah Choi ◽  
Mark S Cembrowski ◽  
William L Kath ◽  
Joshua H Singer
Keyword(s):  
Gap Junctions ◽  
Amacrine Cells ◽  
Aii Amacrine Cells ◽  
Aii Amacrine

scholarly journals Synaptic Transfer between Rod and Cone Pathways Mediated by AII Amacrine Cells in the Mouse Retina

2018 ◽  
Vol 28 (17) ◽  
pp. 2739-2751.e3 ◽  
Author(s):  
Cole W. Graydon ◽  
Evan E. Lieberman ◽  
Nao Rho ◽  
Kevin L. Briggman ◽  
Joshua H. Singer ◽  
...  
Keyword(s):  
Amacrine Cells ◽  
Mouse Retina ◽  
Aii Amacrine Cells ◽  
Aii Amacrine

Ectopic localization of putative AII amacrine cells in the outer plexiform layer of the developing FVB/N mouse retina

2004 ◽  
Vol 315 (3) ◽  
pp. 407-412 ◽  
Author(s):  
Sung-Jin Park ◽  
Eun-Jin Lim ◽  
Su-Ja Oh ◽  
Jin-Woong Chung ◽  
Dennis W. Rickman ◽  
...  
Keyword(s):  
Plexiform Layer ◽  
Amacrine Cells ◽  
Outer Plexiform Layer ◽  
Mouse Retina ◽  
Aii Amacrine Cells ◽  
Aii Amacrine

Electrical Synapses Between AII Amacrine Cells: Dynamic Range and Functional Consequences of Variation in Junctional Conductance

2008 ◽  
Vol 100 (6) ◽  
pp. 3305-3322 ◽  
Author(s):  
Margaret Lin Veruki ◽  
Leif Oltedal ◽  
Espen Hartveit
Keyword(s):  
Dynamic Range ◽  
Amacrine Cells ◽  
Electrical Synapses ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Junctional Conductance ◽  
Coupled Cells ◽  
Functional Consequences ◽  
Aii Amacrine Cells ◽  
Aii Amacrine

AII amacrine cells form a network of electrically coupled interneurons in the mammalian retina and tracer coupling studies suggest that the junctional conductance ( Gj) can be modulated. However, the dynamic range of Gj and the functional consequences of varying Gj over the dynamic range are unknown. Here we use whole cell recordings from pairs of coupled AII amacrine cells in rat retinal slices to provide direct evidence for physiological modulation of Gj, appearing as a time-dependent increase from about 500 pS to a maximum of about 3,000 pS after 30–90 min of recording. The increase occurred in recordings with low- but not high-resistance pipettes, suggesting that it was related to intracellular washout and perturbation of a modulatory system. Computer simulations of a network of electrically coupled cells verified that our recordings were able to detect and quantify changes in Gj over a large range. Dynamic-clamp electrophysiology, with insertion of electrical synapses between AII amacrine cells, allowed us to finely and reversibly control Gj within the same range observed for physiologically coupled cells and to examine the quantitative relationship between Gj and steady-state coupling coefficient, synchronization of subthreshold membrane potential fluctuations, synchronization and transmission of action potentials, and low-pass filter characteristics. The range of Gj values over which signal transmission was modulated depended strongly on the specific functional parameter examined, with the largest range observed for action potential transmission and synchronization, suggesting that the full range of Gj values observed during spontaneous run-up of coupling could represent a physiologically relevant dynamic range.

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.

AII amacrine cells in the rabbit retina possess AMPA-, NMDA-, GABA-, and glycine-activated currents

2004 ◽  
Vol 21 (2) ◽  
pp. 181-188 ◽  
Author(s):  
CHENGWEN ZHOU ◽  
RAMON F. DACHEUX
Keyword(s):  
Ampa Receptors ◽  
Nmda Antagonist ◽  
Amacrine Cells ◽  
Cation Binding ◽  
Kainate Receptors ◽  
Rabbit Retina ◽  
Whole Cell ◽  
Whole Cell Recordings ◽  
Aii Amacrine Cells ◽  
Aii Amacrine

Physiological properties of ligand-activated currents were characterized for morphologically identified AII amacrine cells in the rabbit retina by using whole-cell recordings in a superfused retina slice preparation. The AII amacrine cells were identified based on their distinct narrow-field, bistratified morphology. In the present study, the whole-cell recordings from AII amacrine cells synaptically isolated from presynaptic influences demonstrated the presence of glutamate AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid) receptors, but no kainate receptors. The presence of only AMPA receptors on rabbit AII amacrine cells is in contrast to an earlier study on rabbit AII amacrine cells by Bloomfield and Xin (2000), but consistent with previous studies on rat AII amacrine cells. In addition, NMDA (N-methyl-D-aspartate) -activated currents blocked by the NMDA antagonist D-AP7 (D-2-amino-7-phosphonoheptanoic acid) were found on the AII amacrine cells. These most likely extrasynaptic NMDA-activated currents were attenuated by the presence of Co2+interacting with Mg2+and Ca2+as they competed for divalent cation-binding sites within the NMDA channel. AII amacrine cells also possessed GABA (γ-aminobutyric acid) -activated currents that were unaffected by the GABACreceptor antagonist TPMPA (1,2,5,6-tetrahydropyridine-4-yl methylphosphinic), but were completely blocked by the GABAAantagonist bicuculline. This indicates that the major inhibitory inputs were mediated by only GABAAreceptors located directly on the AII amacrine cells. Furthermore, although the AII amacrine cells were glycinergic amacrine cells, they also possessed glycine-activated currents that may be mediated by autoreceptors.

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