scholarly journals Author response: Formation of retinal direction-selective circuitry initiated by starburst amacrine cell homotypic contact

2018 ◽  
Author(s):  
Thomas A Ray ◽  
Suva Roy ◽  
Christopher Kozlowski ◽  
Jingjing Wang ◽  
Jon Cafaro ◽  
...  
Keyword(s):  
Amacrine Cell ◽  
Author Response ◽  
Starburst Amacrine Cell

scholarly journals Author response: Retinal direction selectivity in the absence of asymmetric starburst amacrine cell responses

2019 ◽  
Author(s):  
Laura Hanson ◽  
Santhosh Sethuramanujam ◽  
Geoff deRosenroll ◽  
Varsha Jain ◽  
Gautam B Awatramani
Keyword(s):  
Amacrine Cell ◽  
Direction Selectivity ◽  
Author Response ◽  
Cell Responses ◽  
Starburst Amacrine Cell

scholarly journals Origins of direction selectivity in the primate retina

2021 ◽  
Author(s):  
Yeon Jin Kim ◽  
Beth Peterson ◽  
Joanna Crook ◽  
Hannah Joo ◽  
Jiajia Wu ◽  
...  
Keyword(s):  
Neural Coding ◽  
Amacrine Cell ◽  
Cell Types ◽  
Macaque Monkey ◽  
Direction Selectivity ◽  
Bipolar Cells ◽  
Motion Processing ◽  
Motion Direction ◽  
Motion Sensitivity ◽  
Starburst Amacrine Cell

Abstract From mouse to primate, there is a striking discontinuity in our current understanding of the neural coding of motion direction. In non-primate mammals, directionally selective cell types and circuits are a signature feature of the retina, situated at the earliest stage of the visual process1,2. In primates, by contrast, direction selectivity is a hallmark of motion processing areas in visual cortex3,4, but has not been found in the retina, despite significant effort5,6. Here we combined functional recordings of light-evoked responses and connectomic reconstruction to identify diverse direction-selective cell types in the macaque monkey retina with distinctive physiological properties and synaptic motifs. This circuitry includes an ON-OFF ganglion cell type, a spiking, ON-OFF poly-axonal amacrine cell and the starburst amacrine cell, all of which show direction selectivity. Moreover, we found unexpectedly that macaque starburst cells possess a strong, non-GABAergic, antagonistic surround mediated by input from excitatory bipolar cells that is critical for the generation of radial motion sensitivity in these cells. Our findings open a new door to investigation of a novel circuitry that computes motion direction in the primate visual system.

Direction selectivity in a model of the starburst amacrine cell

2004 ◽  
Vol 21 (4) ◽  
pp. 611-625 ◽  
Author(s):  
JOHN J. TUKKER ◽  
W. ROWLAND TAYLOR ◽  
ROBERT G. SMITH
Keyword(s):  
Amacrine Cell ◽  
Dendritic Tree ◽  
Sine Wave ◽  
Direction Selectivity ◽  
Membrane Properties ◽  
Calcium Signal ◽  
Inhibitory Input ◽  
Excitatory Postsynaptic Potential ◽  
Global Signal ◽  
Starburst Amacrine Cell

The starburst amacrine cell (SBAC), found in all mammalian retinas, is thought to provide the directional inhibitory input recorded in On–Off direction-selective ganglion cells (DSGCs). While voltage recordings from the somas of SBACs have not shown robust direction selectivity (DS), the dendritic tips of these cells display direction-selective calcium signals, even when γ-aminobutyric acid (GABAa,c) channels are blocked, implying that inhibition is not necessary to generate DS. This suggested that the distinctive morphology of the SBAC could generate a DS signal at the dendritic tips, where most of its synaptic output is located. To explore this possibility, we constructed a compartmental model incorporating realistic morphological structure, passive membrane properties, and excitatory inputs. We found robust DS at the dendritic tips but not at the soma. Two-spot apparent motion and annulus radial motion produced weak DS, but thin bars produced robust DS. For these stimuli, DS was caused by the interaction of a local synaptic input signal with a temporally delayed “global” signal, that is, an excitatory postsynaptic potential (EPSP) that spread from the activated inputs into the soma and throughout the dendritic tree. In the preferred direction the signals in the dendritic tips coincided, allowing summation, whereas in the null direction the local signal preceded the global signal, preventing summation. Sine-wave grating stimuli produced the greatest amount of DS, especially at high velocities and low spatial frequencies. The sine-wave DS responses could be accounted for by a simple mathematical model, which summed phase-shifted signals from soma and dendritic tip. By testing different artificial morphologies, we discovered DS was relatively independent of the morphological details, but depended on having a sufficient number of inputs at the distal tips and a limited electrotonic isolation. Adding voltage-gated calcium channels to the model showed that their threshold effect can amplify DS in the intracellular calcium signal.

scholarly journals Computational and Molecular Properties of Starburst Amacrine Cell Synapses Differ With Postsynaptic Cell Type

2021 ◽  
Vol 15 ◽  
Author(s):  
Joseph Pottackal ◽  
Joshua H. Singer ◽  
Jonathan B. Demb
Keyword(s):  
Amacrine Cell ◽  
Ganglion Cells ◽  
Spatial Scales ◽  
Cell Types ◽  
Inhibitory Synapses ◽  
Mouse Retina ◽  
Presynaptic Neuron ◽  
Postsynaptic Cell ◽  
Low Pass ◽  
Starburst Amacrine Cell

A presynaptic neuron can increase its computational capacity by transmitting functionally distinct signals to each of its postsynaptic cell types. To determine whether such computational specialization occurs over fine spatial scales within a neurite arbor, we investigated computation at output synapses of the starburst amacrine cell (SAC), a critical component of the classical direction-selective (DS) circuit in the retina. The SAC is a non-spiking interneuron that co-releases GABA and acetylcholine and forms closely spaced (<5 μm) inhibitory synapses onto two postsynaptic cell types: DS ganglion cells (DSGCs) and neighboring SACs. During dynamic optogenetic stimulation of SACs in mouse retina, whole-cell recordings of inhibitory postsynaptic currents revealed that GABAergic synapses onto DSGCs exhibit stronger low-pass filtering than those onto neighboring SACs. Computational analyses suggest that this filtering difference can be explained primarily by presynaptic properties, rather than those of the postsynaptic cells per se. Consistent with functionally diverse SAC presynapses, blockade of N-type voltage-gated calcium channels abolished GABAergic currents in SACs but only moderately reduced GABAergic and cholinergic currents in DSGCs. These results jointly demonstrate how specialization of synaptic outputs could enhance parallel processing in a compact interneuron over fine spatial scales. Moreover, the distinct transmission kinetics of GABAergic SAC synapses are poised to support the functional diversity of inhibition within DS circuitry.

Receptive-field properties of displaced starburst amacrine cells change following axotomy-induced degeneration of ganglion cells

1995 ◽  
Vol 12 (1) ◽  
pp. 177-184 ◽  
Author(s):  
Ralph J. Jensen
Keyword(s):  
Receptive Field ◽  
Amacrine Cell ◽  
Ganglion Cells ◽  
Amacrine Cells ◽  
Membrane Properties ◽  
Optic Disk ◽  
Receptive Field Properties ◽  
Tungsten Microelectrode ◽  
Starburst Amacrine Cells ◽  
Starburst Amacrine Cell

AbstractStarburst amacrine cells in the rabbit retina were labeled following an intraocular injection of the fluorescent dye, 4, 6, diamidino-2-phenylindole (DAPI). From each eye a strip of retina was removed, mounted on a platform beneath an epifluorescence microscope, and superfused with a physiological solution. The tip of a tungsten microelectrode (for extracellular recording) was visually positioned near the cell body of a DAPI-labeled starburst amacrine cell that was located in the ganglion cell layer. Light-evoked responses from the displaced starburst amacrine cells were studied in normal retinas and in retinas that had received a small electrolytic lesion near the optic disk 5–9 months beforehand. In normal retinas, a small spot of light centered over the receptive field of a displaced starburst amacrine cell in nearly all cases evoked a brief burst of spikes only at light onset. When stimulated with a large spot or an annulus of light, many cells gave a small burst of spikes at light offset. In lesioned retinas, the light responses of displaced starburst amacrine cells were recorded in areas of the retina where ganglion cells had degenerated. All cells responded with a large burst of spikes at the onset and offset of a small, centered spot of light. Large spots and annuli of light also evoked robust ON/OFF responses from these cells. The results from this study show that the receptive-field properties of displaced starburst amacrine cells change following axotomy-induced degeneration of ganglion cells. This finding indicates that changes in either synaptic transmission or the membrane properties of neurons occur in the retina following degeneration of ganglion cells.

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