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Functional allocation of synaptic contacts in microcircuits from rods via rod bipolar to AII amacrine cells in the mouse retina.

Tsukamoto Y, Omi N - J. Comp. Neurol. (2013)

Bottom Line: In more detail, over 50% of each RB output was directed predominantly to a single, preferred AII amacrine cell, although each RB cell also separately contacted another one to three AII amacrine cells.Thus the original signal may be reliably represented by signal amplification with focal accumulation without gathering unnecessary noise from a wide surrounding area.This allocation of RB-AII synaptic contacts may serve as the structural basis for the physiological properties of the AII single-photon response that include high amplification, local adaptation, and regenerative acceleration.

View Article: PubMed Central - PubMed

Affiliation: Studio Retina, Satonaka, Nishinomiya, Hyogo, 663-8183, Japan; Department of Biology, Hyogo College of Medicine, Nishinomiya, Hyogo, 663-8501, Japan.

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Map of RB synapses. A total of 174 rods synaptically converged to AII amacrine cell 3 through nine RB cells. The rods are shown divided into four groups: 1) 41 rods converging through a pair of Rbs, 2) 124 rods converging through one of the nine RB cells and one more RB cell outside the group of nine (not shown) or a type 7 On cone bipolar cell (asterisk), 3) three rods converging through the invaginating double dendrite of an RB cell (at RB14, 17, and 22), and 4) six rods converging through the Y-shaped RB invaginating dendrite (at RB16, 19, 20, and 21). The dotted contours in different colors indicate the dendritic fields of the nine RB cells (RB14–22). A bar of each color represents one of the RB invaginating dendrites. The number of rods converging onto each RB cell ranges from 24 to 27, with an average of 25, except for RB15 in the upper left, for which only 15 bars are shown because the others were not reconstructed (outside the series). Scale bar = 5 μm.
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fig03: Map of RB synapses. A total of 174 rods synaptically converged to AII amacrine cell 3 through nine RB cells. The rods are shown divided into four groups: 1) 41 rods converging through a pair of Rbs, 2) 124 rods converging through one of the nine RB cells and one more RB cell outside the group of nine (not shown) or a type 7 On cone bipolar cell (asterisk), 3) three rods converging through the invaginating double dendrite of an RB cell (at RB14, 17, and 22), and 4) six rods converging through the Y-shaped RB invaginating dendrite (at RB16, 19, 20, and 21). The dotted contours in different colors indicate the dendritic fields of the nine RB cells (RB14–22). A bar of each color represents one of the RB invaginating dendrites. The number of rods converging onto each RB cell ranges from 24 to 27, with an average of 25, except for RB15 in the upper left, for which only 15 bars are shown because the others were not reconstructed (outside the series). Scale bar = 5 μm.

Mentions: AII 3 collected rod-driven signals from 174 rods through nine (eight completely and one incompletely reconstructed) RB cells, as shown in Figure 3. The number of rods converging on each RB cell ranged from 24 to 27, with an average of 25 (25 ± 1, n = 8), except for RB15 in the upper left of Figure 3 (for which only 15 rods were identified because of the end of the series). Each of the 41 rods (23.6%) contacted a pair of invaginating dendrites of different RB cells among the nine RB cells connected to AII 3. Each of the 124 rods contacted one invaginating dendrite extending from one of the nine RB cells and with another invaginating dendrite (not shown in Fig. 3) extending from an RB cell outside these nine RB cells (122 rods, 70.1%) or a type 7 On cone bipolar cell (two rods, 1.1%; Tsukamoto et al, 2007). Three other rods (1.7%) contacted a pair of invaginating dendrites branching from a proximal RB dendrite outside the spherule, and each of the remaining six rods (3.4%) contacted a Y-shaped RB invaginating dendrite that bifurcated within the spherule. Thus, most of the rods (93.7%) diverged to two RB cells, but a small number (6.3%) of rods diverged to one RB cell, yielding an average divergence of 1.94.


Functional allocation of synaptic contacts in microcircuits from rods via rod bipolar to AII amacrine cells in the mouse retina.

Tsukamoto Y, Omi N - J. Comp. Neurol. (2013)

Map of RB synapses. A total of 174 rods synaptically converged to AII amacrine cell 3 through nine RB cells. The rods are shown divided into four groups: 1) 41 rods converging through a pair of Rbs, 2) 124 rods converging through one of the nine RB cells and one more RB cell outside the group of nine (not shown) or a type 7 On cone bipolar cell (asterisk), 3) three rods converging through the invaginating double dendrite of an RB cell (at RB14, 17, and 22), and 4) six rods converging through the Y-shaped RB invaginating dendrite (at RB16, 19, 20, and 21). The dotted contours in different colors indicate the dendritic fields of the nine RB cells (RB14–22). A bar of each color represents one of the RB invaginating dendrites. The number of rods converging onto each RB cell ranges from 24 to 27, with an average of 25, except for RB15 in the upper left, for which only 15 bars are shown because the others were not reconstructed (outside the series). Scale bar = 5 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4265793&req=5

fig03: Map of RB synapses. A total of 174 rods synaptically converged to AII amacrine cell 3 through nine RB cells. The rods are shown divided into four groups: 1) 41 rods converging through a pair of Rbs, 2) 124 rods converging through one of the nine RB cells and one more RB cell outside the group of nine (not shown) or a type 7 On cone bipolar cell (asterisk), 3) three rods converging through the invaginating double dendrite of an RB cell (at RB14, 17, and 22), and 4) six rods converging through the Y-shaped RB invaginating dendrite (at RB16, 19, 20, and 21). The dotted contours in different colors indicate the dendritic fields of the nine RB cells (RB14–22). A bar of each color represents one of the RB invaginating dendrites. The number of rods converging onto each RB cell ranges from 24 to 27, with an average of 25, except for RB15 in the upper left, for which only 15 bars are shown because the others were not reconstructed (outside the series). Scale bar = 5 μm.
Mentions: AII 3 collected rod-driven signals from 174 rods through nine (eight completely and one incompletely reconstructed) RB cells, as shown in Figure 3. The number of rods converging on each RB cell ranged from 24 to 27, with an average of 25 (25 ± 1, n = 8), except for RB15 in the upper left of Figure 3 (for which only 15 rods were identified because of the end of the series). Each of the 41 rods (23.6%) contacted a pair of invaginating dendrites of different RB cells among the nine RB cells connected to AII 3. Each of the 124 rods contacted one invaginating dendrite extending from one of the nine RB cells and with another invaginating dendrite (not shown in Fig. 3) extending from an RB cell outside these nine RB cells (122 rods, 70.1%) or a type 7 On cone bipolar cell (two rods, 1.1%; Tsukamoto et al, 2007). Three other rods (1.7%) contacted a pair of invaginating dendrites branching from a proximal RB dendrite outside the spherule, and each of the remaining six rods (3.4%) contacted a Y-shaped RB invaginating dendrite that bifurcated within the spherule. Thus, most of the rods (93.7%) diverged to two RB cells, but a small number (6.3%) of rods diverged to one RB cell, yielding an average divergence of 1.94.

Bottom Line: In more detail, over 50% of each RB output was directed predominantly to a single, preferred AII amacrine cell, although each RB cell also separately contacted another one to three AII amacrine cells.Thus the original signal may be reliably represented by signal amplification with focal accumulation without gathering unnecessary noise from a wide surrounding area.This allocation of RB-AII synaptic contacts may serve as the structural basis for the physiological properties of the AII single-photon response that include high amplification, local adaptation, and regenerative acceleration.

View Article: PubMed Central - PubMed

Affiliation: Studio Retina, Satonaka, Nishinomiya, Hyogo, 663-8183, Japan; Department of Biology, Hyogo College of Medicine, Nishinomiya, Hyogo, 663-8501, Japan.

Show MeSH
Related in: MedlinePlus