scholarly journals Inhibitory inputs tune the light response properties of dopaminergic amacrine cells in mouse retina

2013 ◽  
Vol 110 (2) ◽  
pp. 536-552 ◽  
Author(s):  
G. S. Newkirk ◽  
M. Hoon ◽  
R. O. Wong ◽  
P. B. Detwiler
Keyword(s):  
Visual Processing ◽  
Fluorescent Protein ◽  
Bright Light ◽  
Light Response ◽  
Amacrine Cells ◽  
Membrane Properties ◽  
Mouse Retina ◽  
Light Onset ◽  
Threshold Response ◽  
Green Fluorescent

Dopamine (DA) is a neuromodulator that in the retina adjusts the circuitry for visual processing in dim and bright light conditions. It is synthesized and released from retinal interneurons called dopaminergic amacrine cells (DACs), whose basic physiology is not yet been fully characterized. To investigate their cellular and input properties as well as light responses, DACs were targeted for whole cell recording in isolated retina using two-photon fluorescence microscopy in a mouse line where the dopamine receptor 2 promoter drives green fluorescent protein (GFP) expression. Differences in membrane properties gave rise to cell-to-cell variation in the pattern of resting spontaneous spike activity ranging from silent to rhythmic to periodic burst discharge. All recorded DACs were light sensitive and generated responses that varied with intensity. The threshold response to light onset was a hyperpolarizing potential change initiated by rod photoreceptors that was blocked by strychnine, indicating a glycinergic amacrine input onto DACs at light onset. With increasing light intensity, the ON response acquired an excitatory component that grew to dominate the response to the strongest stimuli. Responses to bright light (photopic) stimuli also included an inhibitory OFF response mediated by GABAergic amacrine cells driven by the cone OFF pathway. DACs expressed GABA (GABAAα1 and GABAAα3) and glycine (α2) receptor clusters on soma, axon, and dendrites consistent with the light response being shaped by dual inhibitory inputs that may serve to tune spike discharge for optimal DA release.

scholarly journals Asymmetric Distributions of Achromatic Bipolar Cells in the Mouse Retina

2022 ◽  
Vol 15 ◽  
Author(s):  
Zachary J. Sharpe ◽  
Angela Shehu ◽  
Tomomi Ichinose
Keyword(s):  
Visual Processing ◽  
Fluorescent Protein ◽  
Bipolar Cells ◽  
Mouse Retina ◽  
Temporal Region ◽  
Retinal Tissue ◽  
Evolutionary Changes ◽  
Asymmetric Distributions ◽  
Nasal Region ◽  
Green Fluorescent

In the retina, evolutionary changes can be traced in the topography of photoreceptors. The shape of the visual streak depends on the height of the animal and its habitat, namely, woods, prairies, or mountains. Also, the distribution of distinct wavelength-sensitive cones is unique to each animal. For example, UV and green cones reside in the ventral and dorsal regions in the mouse retina, respectively, whereas in the rat retina these cones are homogeneously distributed. In contrast with the abundant investigation on the distribution of photoreceptors and the third-order neurons, the distribution of bipolar cells has not been well understood. We utilized two enhanced green fluorescent protein (EGFP) mouse lines, Lhx4-EGFP (Lhx4) and 6030405A18Rik-EGFP (Rik), to examine the topographic distributions of bipolar cells in the retina. First, we characterized their GFP-expressing cells using type-specific markers. We found that GFP was expressed by type 2, type 3a, and type 6 bipolar cells in the Rik mice and by type 3b, type 4, and type 5 bipolar cells in the Lhx4 mice. All these types are achromatic. Then, we examined the distributions of bipolar cells in the four cardinal directions and three different eccentricities of the retinal tissue. In the Rik mice, GFP-expressing bipolar cells were more highly observed in the nasal region than those in the temporal retina. The number of GFP cells was not different along with the ventral-dorsal axis. In contrast, in the Lhx4 mice, GFP-expressing cells occurred at a higher density in the ventral region than in the dorsal retina. However, no difference was observed along the nasal-temporal axis. Furthermore, we examined which type of bipolar cells contributed to the asymmetric distributions in the Rik mice. We found that type 3a bipolar cells occurred at a higher density in the temporal region, whereas type 6 bipolar cells were denser in the nasal region. The asymmetricity of these bipolar cells shaped the uneven distribution of the GFP cells in the Rik mice. In conclusion, we found that a subset of achromatic bipolar cells is asymmetrically distributed in the mouse retina, suggesting their unique roles in achromatic visual processing.

scholarly journals Local processing in neurites of VGluT3-expressing amacrine cells differentially organizes visual information

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Jen-Chun Hsiang ◽  
Keith P Johnson ◽  
Linda Madisen ◽  
Hongkui Zeng ◽  
Daniel Kerschensteiner
Keyword(s):  
Visual Processing ◽  
Visual Information ◽  
Receptive Fields ◽  
Visual Space ◽  
Amacrine Cells ◽  
Object Motion ◽  
Image Motion ◽  
Local Processing ◽  
Mouse Retina ◽  
Population Activity

Neurons receive synaptic inputs on extensive neurite arbors. How information is organized across arbors and how local processing in neurites contributes to circuit function is mostly unknown. Here, we used two-photon Ca2+ imaging to study visual processing in VGluT3-expressing amacrine cells (VG3-ACs) in the mouse retina. Contrast preferences (ON vs. OFF) varied across VG3-AC arbors depending on the laminar position of neurites, with ON responses preferring larger stimuli than OFF responses. Although arbors of neighboring cells overlap extensively, imaging population activity revealed continuous topographic maps of visual space in the VG3-AC plexus. All VG3-AC neurites responded strongly to object motion, but remained silent during global image motion. Thus, VG3-AC arbors limit vertical and lateral integration of contrast and location information, respectively. We propose that this local processing enables the dense VG3-AC plexus to contribute precise object motion signals to diverse targets without distorting target-specific contrast preferences and spatial receptive fields.

scholarly journals A dark quencher genetically encodable voltage indicator (dqGEVI) exhibits high fidelity and speed

2021 ◽  
Vol 118 (6) ◽  
pp. e2020235118
Author(s):  
Therese C. Alich ◽  
Milan Pabst ◽  
Leonie Pothmann ◽  
Bálint Szalontai ◽  
Guido C. Faas ◽  
...  
Keyword(s):  
Large Scale ◽  
Fluorescent Protein ◽  
Single Photon ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Membrane Properties ◽  
Neuronal Membrane ◽  
High Temporal Resolution ◽  
Action Potential Firing ◽  
Green Fluorescent

Voltage sensing with genetically expressed optical probes is highly desirable for large-scale recordings of neuronal activity and detection of localized voltage signals in single neurons. Most genetically encodable voltage indicators (GEVI) have drawbacks including slow response, low fluorescence, or excessive bleaching. Here we present a dark quencher GEVI approach (dqGEVI) using a Förster resonance energy transfer pair between a fluorophore glycosylphosphatidylinositol–enhanced green fluorescent protein (GPI-eGFP) on the outer surface of the neuronal membrane and an azo-benzene dye quencher (D3) that rapidly moves in the membrane driven by voltage. In contrast to previous probes, the sensor has a single photon bleaching time constant of ∼40 min, has a high temporal resolution and fidelity for detecting action potential firing at 100 Hz, resolves membrane de- and hyperpolarizations of a few millivolts, and has negligible effects on passive membrane properties or synaptic events. The dqGEVI approach should be a valuable tool for optical recordings of subcellular or population membrane potential changes in nerve cells.

scholarly journals Endomorphin-1 Modulates Intrinsic Inhibition in the Dorsal Vagal Complex

2007 ◽  
Vol 98 (3) ◽  
pp. 1591-1599 ◽  
Author(s):  
Nicholas R. Glatzer ◽  
Andrei V. Derbenev ◽  
Bruce W. Banfield ◽  
Bret N. Smith
Keyword(s):  
Fluorescent Protein ◽  
Nucleus Tractus Solitarius ◽  
Afferent Input ◽  
Membrane Properties ◽  
Motor Nucleus ◽  
Action Potential Firing ◽  
Postsynaptic Currents ◽  
Gaba Neurons ◽  
Green Fluorescent ◽  
Stimulation Of

Mu-opioid receptor (MOR) agonists profoundly influence digestive and other autonomic functions by modulating neurons in nucleus tractus solitarius (NTS) and dorsal motor nucleus of the vagus (DMV). Whole cell recordings were made from NTS and DMV neurons in brain stem slices from rats and transgenic mice that expressed enhanced green fluorescent protein (EGFP) under the control of a GAD67 promoter (EGFP-GABA neurons) to identify opioid-mediated effects on GABAergic circuitry. Synaptic and membrane properties of EGFP-GABA neurons were assessed. The endogenous selective MOR agonist endomorphin-1 (EM-1) reduced spontaneous and evoked excitatory postsynaptic currents (EPSCs) and inhibitory postsynaptic currents (IPSCs) in both rat and mouse DMV neurons. Electrical stimulation of the solitary tract evoked constant-latency EPSCs in ∼50% of EGFP-GABA neurons, and the responses were reduced by EM-1 application. EM-1 reduced action potential firing, the frequency and amplitude of synaptic inputs in EGFP-GABA neurons and responses to direct glutamate stimulation. A subset of EGFP-GABA neurons colocalized mRFP1 after retrograde, transneuronal infection after gastric inoculation with PRV-614, indicating that they synapsed with gastric-projecting DMV neurons. Glutamate photolysis stimulation of intact NTS projections evoked IPSCs in DMV neurons, and EM-1 reduced the evoked response, most likely by activation of MOR on the soma of premotor GABA neurons in NTS. Naltrexone or H-d-Phe-Cys-Tyr-d-Trp-Arg-Thr-Pen-Thr-NH2 (CTAP), MOR antagonists, blocked the effects of EM-1. Our results show that GABA neurons in the NTS receive direct vagal afferent input and project to gastric-related DMV neurons. Furthermore, modulation by EM-1 of specific components of the vagal complex differentially suppresses excitatory and inhibitory synaptic input to the DMV by acting at different receptor locations.

Glycine receptors of A-type ganglion cells of the mouse retina

2007 ◽  
Vol 24 (4) ◽  
pp. 471-487 ◽  
Author(s):  
SRIPARNA MAJUMDAR ◽  
LIANE HEINZE ◽  
SILKE HAVERKAMP ◽  
ELENA IVANOVA ◽  
HEINZ WÄSSLE
Keyword(s):  
Fluorescent Protein ◽  
Ganglion Cells ◽  
Glycine Receptor ◽  
Mouse Retina ◽  
Inhibitory Input ◽  
Visual Channel ◽  
Fast Kinetics ◽  
Transgenic Mouse Line ◽  
Green Fluorescent ◽  
Α Subunits

A-type ganglion cells of the mouse retina represent the visual channel that transfers temporal changes of the outside world very fast and with high fidelity. In this study we combined anatomical and physiological methods in order to study the glycinergic, inhibitory input of A-type ganglion cells. Immunocytochemical studies were performed in a transgenic mouse line whose ganglion cells express green fluorescent protein (GFP). The cells were double labeled for GFP and the four α subunits of the glycine receptor (GlyR). It was found that most of the glycinergic input of A-type cells is through fast, α1-expressing synapses. Whole-cell currents were recorded from A-type ganglion cells in retinal whole mounts. The response to exogenous application of glycine and spontaneous inhibitory postsynaptic currents (sIPSCs) were measured. By comparing glycinergic currents recorded in wildtype mice and in mice with specific deletions of GlyRα subunits (Glra1spd-ot,Glra2−/−,Glra3−/−), the subunit composition of GlyRs of A-type ganglion cells could be further defined. Glycinergic sIPSCs of A-type ganglion cells have fast kinetics (decay time constant τ = 3.9 ± 2.5 ms, mean ± SD). Glycinergic sIPSCs recorded inGlra2−/−andGlra3−/−mice did not differ from those of wildtype mice. However, the number of glycinergic sIPSCs was significantly reduced inGlra1spd-otmice and the remaining sIPSCs had slower kinetics than in wildtype mice. The results show that A-type ganglion cells receive preferentially kinetically fast glycinergic inputs, mediated by GlyRs composed of α1 and β subunits.

scholarly journals Properties of Mouse Spinal Lamina I GABAergic Interneurons

2005 ◽  
Vol 94 (5) ◽  
pp. 3221-3227 ◽  
Author(s):  
Kimberly J. Dougherty ◽  
Michael A. Sawchuk ◽  
Shawn Hochman
Keyword(s):  
Fluorescent Protein ◽  
Membrane Properties ◽  
Sensory Response ◽  
Initial Burst ◽  
Lamina I ◽  
Single Spike ◽  
Relay Region ◽  
Current Steps ◽  
Firing Properties ◽  
Green Fluorescent

Lamina I is a sensory relay region containing projection cells and local interneurons involved in thermal and nociceptive signaling. These neurons differ in morphology, sensory response modality, and firing characteristics. We examined intrinsic properties of mouse lamina I GABAergic neurons expressing enhanced green fluorescent protein (EGFP). GABAergic neuron identity was confirmed by a high correspondence between GABA immunolabeling and EGFP fluorescence. Morphologies of these EGFP+/GABA+ cells were multipolar (65%), fusiform (31%), and pyramidal (4%). In whole cell recordings, cells fired a single spike (44%), tonically (35%), or an initial burst (21%) in response to current steps, representing a subset of reported lamina I firing properties. Membrane properties of tonic and initial burst cells were indistinguishable and these neurons may represent one functional population because, in individual neurons, their firing patterns could interconvert. Single spike cells were less excitable with lower membrane resistivity and higher rheobase. Most fusiform cells (64%) fired tonically while most multipolar cells (56%) fired single spikes. In summary, lamina I inhibitory interneurons are functionally divisible into at least two major groups both of which presumably function to limit excitatory transmission.

scholarly journals Biomolecular Contrast Agents for Optical Coherence Tomography

2019 ◽  
Author(s):  
George J. Lu ◽  
Li-dek Chou ◽  
Dina Malounda ◽  
Amit K. Patel ◽  
Derek S. Welsbie ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Contrast Agents ◽  
Fluorescent Protein ◽  
Mouse Retina ◽  
Optical Coherence ◽  
Gas Vesicles ◽  
Cellular Functions ◽  
Green Fluorescent

ABSTRACTOptical coherence tomography (OCT) has gained wide adoption in biological and medical imaging due to its exceptional tissue penetration, 3D imaging speed and rich contrast. However, OCT plays a relatively small role in molecular and cellular imaging due to the lack of suitable biomolecular contrast agents. In particular, while the green fluorescent protein has provided revolutionary capabilities to fluorescence microscopy by connecting it to cellular functions such as gene expression, no equivalent reporter gene is currently available for OCT. Here we introduce gas vesicles, a unique class of naturally evolved gas-filled protein nanostructures, as the first genetically encodable OCT contrast agents. The differential refractive index of their gas compartments relative to surrounding aqueous tissue and their nanoscale motion enables gas vesicles to be detected by static and dynamic OCT at picomolar concentrations. Furthermore, the OCT contrast of gas vesicles can be selectively erasedin situwith ultrasound, allowing unambiguous assignment of their location. In addition, gas vesicle clustering modulates their temporal signal, enabling the design of dynamic biosensors. We demonstrate the use of gas vesicles as reporter genes in bacterial colonies and as purified contrast agentsin vivoin the mouse retina. Our results expand the utility of OCT as a unique photonic modality to image a wider variety of cellular and molecular processes.

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.

scholarly journals Genetic targeting and physiological features of VGLUT3+ amacrine cells

2011 ◽  
Vol 28 (5) ◽  
pp. 381-392 ◽  
Author(s):  
WILLIAM N. GRIMES ◽  
REBECCA P. SEAL ◽  
NICHOLAS OESCH ◽  
ROBERT H. EDWARDS ◽  
JEFFREY S. DIAMOND
Keyword(s):  
Time Course ◽  
Fluorescent Protein ◽  
Yellow Fluorescent Protein ◽  
Glutamate Transporter ◽  
Amacrine Cells ◽  
Bipolar Cells ◽  
Membrane Properties ◽  
Visual Signal ◽  
Transgenic Mouse Line ◽  
Electrophysiological Recordings

AbstractAmacrine cells constitute a diverse class of interneurons that contribute to visual signal processing in the inner retina, but surprisingly, little is known about the physiology of most amacrine cell subtypes. Here, we have taken advantage of the sparse expression of vesicular glutamate transporter 3 (VGLUT3) in the mammalian retina to target the expression of yellow fluorescent protein (YFP) to a unique population of amacrine cells using a new transgenic mouse line. Electrophysiological recordings made from YFP-positive (VGLUT3+) amacrine cells provide the first functional data regarding the active membrane properties and synaptic connections of this recently identified cell type. We found that VGLUT3+ amacrine cells receive direct synaptic input from bipolar cells via both N-methyl-d-aspartate receptors (NMDARs) and non-NMDARs. Voltage-gated sodium channels amplified these excitatory inputs but repetitive spiking was never observed. VGLUT3+ amacrine cells responded transiently to both light increments (ON response) and decrements (OFF response); ON responses consisted exclusively of inhibitory inputs, while OFF responses comprised both excitatory and inhibitory components, although the inhibitory conductance was larger in amplitude and longer in time course. The physiological properties and anatomical features of the VGLUT3+ amacrine cells suggest that this bistratified interneuron may play a role in disinhibitory signaling and/or crossover inhibition between parallel pathways in the retina.

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