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Maruyama T, Mano A, Ishii T, Kakinuma Y, Kaneda M. P2X 2 receptors supply extracellular choline as a substrate for acetylcholine synthesis. FEBS Open Bio 2021; 12:250-257. [PMID: 34787962 PMCID: PMC8727932 DOI: 10.1002/2211-5463.13332] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 11/03/2021] [Accepted: 11/16/2021] [Indexed: 01/14/2023] Open
Abstract
Acetylcholine (ACh), an excitatory neurotransmitter, is biosynthesized from choline in cholinergic neurons. Import from the extracellular space to the intracellular environment through the high-affinity choline transporter is currently regarded to be the only source of choline for ACh synthesis. We recently demonstrated that the P2X2 receptor, through which large cations permeate, functions as an alternative pathway for choline transport in the mouse retina. In the present study, we investigated whether choline entering cells through P2X2 receptors is used for ACh synthesis using a recombinant system. When P2X2 receptors expressed on HEK293 cell lines were stimulated with ATP, intracellular ACh concentrations increased. These results suggest that P2X2 receptors function in a novel pathway that supplies choline for ACh synthesis.
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Affiliation(s)
- Takuma Maruyama
- Department of Physiology, Nippon Medical School, Tokyo, Japan
| | - Asuka Mano
- Department of Physiology, Nippon Medical School, Tokyo, Japan
| | - Toshiyuki Ishii
- Department of Physiology, Nippon Medical School, Tokyo, Japan
| | | | - Makoto Kaneda
- Department of Physiology, Nippon Medical School, Tokyo, Japan
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2
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Matzner A, Gorodetski L, Korngreen A, Bar-Gad I. Dynamic input-dependent encoding of individual basal ganglia neurons. Sci Rep 2020; 10:5833. [PMID: 32242059 PMCID: PMC7118110 DOI: 10.1038/s41598-020-62750-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 03/16/2020] [Indexed: 11/09/2022] Open
Abstract
Computational models are crucial to studying the encoding of individual neurons. Static models are composed of a fixed set of parameters, thus resulting in static encoding properties that do not change under different inputs. Here, we challenge this basic concept which underlies these models. Using generalized linear models, we quantify the encoding and information processing properties of basal ganglia neurons recorded in-vitro. These properties are highly sensitive to the internal state of the neuron due to factors such as dependency on the baseline firing rate. Verification of these experimental results with simulations provides insights into the mechanisms underlying this input-dependent encoding. Thus, static models, which are not context dependent, represent only part of the neuronal encoding capabilities, and are not sufficient to represent the dynamics of a neuron over varying inputs. Input-dependent encoding is crucial for expanding our understanding of neuronal behavior in health and disease and underscores the need for a new generation of dynamic neuronal models.
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Affiliation(s)
- Ayala Matzner
- The Leslie & Susan Goldschmied (Gonda) Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel
| | - Lilach Gorodetski
- Goodman Faculty of life sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Alon Korngreen
- The Leslie & Susan Goldschmied (Gonda) Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel.,Goodman Faculty of life sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Izhar Bar-Gad
- The Leslie & Susan Goldschmied (Gonda) Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel.
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3
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Sethuramanujam S, McLaughlin AJ, deRosenroll G, Hoggarth A, Schwab DJ, Awatramani GB. A Central Role for Mixed Acetylcholine/GABA Transmission in Direction Coding in the Retina. Neuron 2016; 90:1243-1256. [PMID: 27238865 DOI: 10.1016/j.neuron.2016.04.041] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 03/09/2016] [Accepted: 04/18/2016] [Indexed: 11/27/2022]
Abstract
A surprisingly large number of neurons throughout the brain are endowed with the ability to co-release both a fast excitatory and inhibitory transmitter. The computational benefits of dual transmitter release, however, remain poorly understood. Here, we address the role of co-transmission of acetylcholine (ACh) and GABA from starburst amacrine cells (SACs) to direction-selective ganglion cells (DSGCs). Using a combination of pharmacology, optogenetics, and linear regression methods, we estimated the spatiotemporal profiles of GABA, ACh, and glutamate receptor-mediated synaptic activity in DSGCs evoked by motion. We found that ACh initiates responses to motion in natural scenes or under low-contrast conditions. In contrast, classical glutamatergic pathways play a secondary role, amplifying cholinergic responses via NMDA receptor activation. Furthermore, under these conditions, the network of SACs differentially transmits ACh and GABA to DSGCs in a directional manner. Thus, mixed transmission plays a central role in shaping directional responses of DSGCs.
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Affiliation(s)
| | | | | | - Alex Hoggarth
- Department of Biology, University of Victoria, Victoria, BC V8W 3N5, Canada
| | - David J Schwab
- Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208, USA
| | - Gautam B Awatramani
- Department of Biology, University of Victoria, Victoria, BC V8W 3N5, Canada.
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4
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Akopian A. Differential modulation of light-evoked on- and off-EPSCs by paired-pulse stimulation in salamander retinal ganglion cells. Brain Res 2003; 967:235-46. [PMID: 12650984 DOI: 10.1016/s0006-8993(03)02243-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Short-term plasticity of On- and Off-EPSPs, and its potential role in regulation of signal processing was studied in salamander retinal On-Off ganglion cells by whole-cell recording. Paired-pulse light stimulation resulted in a depression of On-, and an enhancement of Off-EPSCs. Recovery from depression and enhancement was exponential and complete by 20 s. Paired-pulse enhancement, but not depression, was abolished with increasing stimulus duration. Blockade of On-EPSC by L-2-amino-4-phosphonobutyrate (AP-4), an agonist at group III mGluRs, significantly increased Off-EPSCs evoked by short (<2 s) duration conditioning light stimuli, resulting in a reversal of the paired-pulse enhancement to depression. The acetylcholinesterase inhibitor eserine reduced Off-EPSC1 and increased the ratio of enhancement. An opposite effect was observed in the presence of the nACh receptor antagonist d-tubocurarine. AP-7, an antagonist of NMDA receptors attenuated the enhancement of Off-EPSCs. In current clamp mode paired-pulse stimulation resulted in a modulation of light evoked, as well as the depolarization-induced spike firing pattern of ganglion cells. The present study suggests that paired light stimulation differently modulates On and Off EPSPs, and the light-evoked spike firing pattern of On-Off ganglion cells.
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Affiliation(s)
- Abram Akopian
- Department of Ophthalmology, New York University School of Medicine, NY 10016, USA.
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5
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Cohen ED, Miller RF. Quinoxalines block the mechanism of directional selectivity in ganglion cells of the rabbit retina. Proc Natl Acad Sci U S A 1995; 92:1127-31. [PMID: 7862647 PMCID: PMC42651 DOI: 10.1073/pnas.92.4.1127] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Direction selectivity is a receptive field property displayed by neurons throughout the visual system. Previous experiments have concentrated on the role of lateral connections that use gamma-aminobutyric acid and acetylcholine. We have examined the role of excitatory amino acid receptors on direction-selective ganglion cell function in the rabbit retina. Application of the quinoxalines, a group of kainate/alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor antagonists, selectively blocked the directional-selectivity mechanism, leaving cells responsive to both directions of movement. In contrast, direction selectivity was unaffected by N-methyl-D-aspartate receptor antagonists or L-2-amino-4-phosphonobutyric acid. Large reductions in acetylcholine release by starburst amacrine cells appear to parallel losses of direction selectivity observed in the quinoxalines. These results shed additional insights into the mechanism of direction selectivity.
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Affiliation(s)
- E D Cohen
- Department of Ophthalmology and Visual Science, Yale School of Medicine, New Haven, CT 06520-8061
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6
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Boelen MK, Dowton M, Morgan IG. [Leu5]enkephalin-like immunoreactive amacrine cells are under nicotinic excitatory control during darkness in chicken retina. Brain Res 1993; 624:137-42. [PMID: 8252386 DOI: 10.1016/0006-8993(93)90071-t] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Based on the principle that retinal levels of [Leu5]enkephalin-like immunoreactivity (LELI) are set by the rate of release and thus reflect neural activity, we partially defined the dark-associated increase in excitatory control of LELI amacrine cells in chicken. Retinal levels of LELI were measured by radioimmunoassay (RIA). Intravitreal injection of cholinergic antagonists decreased the rate of depletion of LELI during the dark phase, suggesting the presence of cholinergic excitatory control of the LELI neurons. This cholinergic control involves nicotinic rather than muscarinic receptors, as tubocurarine appeared over 100 times more effective than atropine in inhibiting the decrease in retinal levels of LELI in the dark. (The ED50s were estimated at 3.2 and 450 nmol, respectively.) The lack of effect of the antagonists when applied during the light phase, suggest that there is little cholinergic input to the LELI amacrine cells in the light. Superfusing isolated retinas with buffer containing tubocurarine (10 microM) decreased the efflux of LELI by 35%, compared to the spontaneous release during the dark. Atropine (10 microM) had no effect on the release of LELI, and pilocarpine (100 microM) increased the release of LELI from retinas superfused in the light by 20%. We conclude that, in addition to previously reported glycinergic and dopaminergic inhibition, the LELI amacrine cells receive cholinergic excitatory input. A shift in balance between glycinergic and dopaminergic inhibitory, and cholinergic excitatory control may underly the light-driven variation in activity of the LELI neurons in chicken retina.
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Affiliation(s)
- M K Boelen
- Centre for Research on Ageing, La Trobe University College of Northern Victoria, Bendigo, Australia
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Critz SD, Marc RE. Glutamate antagonists that block hyperpolarizing bipolar cells increase the release of dopamine from turtle retina. Vis Neurosci 1992; 9:271-8. [PMID: 1327088 DOI: 10.1017/s0952523800010683] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Some neurochemical features of the neuronal circuitry regulating dopamine release were examined in the retina of the turtle, Pseudemys scripta elegans. Glutamate antagonists that block hyperpolarizing bipolar cells, such as 2,3 piperidine dicarboxylic acid (PDA), produced dose-dependent dopamine release. In contrast, the glutamate agonist 2-amino-4-phosphonobutyric acid (APB), which blocks depolarizing bipolar cell responses with high specificity, had no effect on the release of dopamine. The gamma-aminobutyric acid (GABA) antagonist, bicuculline, also produced potent dose-dependent release of dopamine. The release of dopamine produced by PDA was blocked by exogenous GABA and muscimol, suggesting that the PDA-mediated release process was polysynaptic and involved a GABAergic synapse interposed between the bipolar and dopaminergic amacrine cells. The only other agents that produced dopamine release were chloride-free media and high extracellular K+; in particular, kainic acid and glutamate itself were ineffective. These results suggest that the primary neuronal chain mediating dopamine release in the turtle retina is: cone----hyperpolarizing bipolar cell----GABAergic amacrine cell----dopaminergic amacrine cell.
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Affiliation(s)
- S D Critz
- Sensory Sciences Center, Graduate School of Biomedical Sciences, University of Texas Health Science Center, Houston 77030
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Jardon B, Bonaventure N, Scherrer E. Possible involvement of cholinergic and glycinergic amacrine cells in the inhibition exerted by the ON retinal channel on the OFF retinal channel. Eur J Pharmacol 1992; 210:201-7. [PMID: 1601057 DOI: 10.1016/0014-2999(92)90672-q] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In the frog retina, the inhibition exerted by the ON channel on the OFF channel was evidenced by the increase in transient ganglion cell OFF responses, when the ON channel was blocked by 2-amino-4-phosphonobutyrate (APB). Intraocular administration of the neurotoxic choline analog ethylcholine mustard arizidinium ion (ECMA) also provoked an increase in the number of spikes of transient ganglion cell OFF responses, without suppressing the ON responses. APB, when administrated after ECMA, abolished the ON responses, but did not modify the OFF responses already increased by ECMA. Neurons located in the inner part of the inner nuclear layer were histologically altered by the toxin, and choline acetyltransferase activity was significantly depressed in ECMA-treated retinas. A double immunostaining experiment showed that amacrine cells containing glycine bear muscarinic binding sites. These results confirm the participation of cholinergic neurons in the inhibition exerted by the ON retinal channel on the OFF retinal channel, and suggest the involvement of a cholinergic/glycinergic loop of amacrine cells in this mechanism.
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Affiliation(s)
- B Jardon
- Laboratoire de Neurophysiologie et Biologie des Comportements, Centre de Neurochimie, Strasbourg, France
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9
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Cubells JF, Ndubuka C, Makman MH. 2-amino-4-phosphonobutyric acid exerts a light-dependent effect on post-gabaculine levels of retinal gamma-aminobutyric acid (GABA): evidence that ON synaptic pathways regulate retinal GABAergic transmission. J Neurochem 1991; 57:46-52. [PMID: 1646863 DOI: 10.1111/j.1471-4159.1991.tb02097.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The effects of light, 2-amino-4-phosphonobutyric acid (APB), and kainic acid on rat retinal gamma-aminobutyric acid (GABA)-ergic transmission were studied by measuring levels of retinal GABA following subcutaneous injection of gabaculine, an irreversible inhibitor of GABA-transaminase. Post-gabaculine levels of retinal GABA in light-exposed rats were significantly greater than those in rats held in darkness. The synaptic mechanism of this effect of light was examined by measuring post-gabaculine levels of retinal GABA in rats placed into either lighted or darkened conditions after receiving unilateral intravitreal injections of APB, a glutamate analogue that selectively decreases the activity of ON synaptic pathways in the retina. APB attenuated the post-gabaculine accumulation of GABA in rats held in the light, but not in those placed into darkness. Furthermore, the light-dependent increment in post-gabaculine accumulation of retinal GABA was entirely APB sensitive, and the effect of APB was entirely light dependent. In contrast to APB, kainic acid stimulated the post-gabaculine accumulation of retinal GABA in vivo. Our findings suggest that APB and kainic acid influence GABAergic transmission at different sites in the retina and that some retinal GABAergic neurons are either ON or ON-OFF amacrine cells.
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Affiliation(s)
- J F Cubells
- Department of Neuroscience, Albert Einstein College of Medicine, New York, NY 10461
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10
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Guité P, Lachapelle P. The effect of 2-amino-4-phosphonobutyric acid on the oscillatory potentials of the electroretinogram. Doc Ophthalmol 1990; 75:125-33. [PMID: 2276313 DOI: 10.1007/bf00146548] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Previous reports have shown that an intravitreal injection of 2-amino-4-phosphonobutyric acid, a glutamate analogue that selectively blocks the photoreceptors' input to the on-bipolar cells, produces a rapid decrease in the amplitude of the electroretinographic b-wave. To our knowledge, the effect of this glutamate analogue has not been examined on the oscillatory potentials. We therefore conducted such a study. A needle electrode was inserted into the anterior chamber of the eyes of seven anesthetized and paralyzed rabbits to record simultaneously the electroretinogram and the oscillatory potentials. These responses were evoked by flashes of white light delivered in mesopic conditions. As expected, an injection of 2-amino-4-phosphonobutyric acid, produced a rapid decrease in the amplitude of the b-wave, while the a-wave was relatively spared. The amplitude of the oscillatory potentials also decreased rapidly. At maximal effect, the electroretinogram essentially consisted of a normal a-wave followed by small oscillations and no evidence of a b-wave. The 100-1000 Hz recording confirmed that the oscillations seen on the postinjection electroretinograms were remnants of the original oscillatory potentials.
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Affiliation(s)
- P Guité
- Department of Neurology and Neurosurgery, McGill University, Montreal, Canada
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11
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Jardon B, Yücel H, Bonaventure N. Glutamatergic separation of ON and OFF retinal channels: possible modulation by glycine and acetylcholine. Eur J Pharmacol 1989; 162:215-24. [PMID: 2785924 DOI: 10.1016/0014-2999(89)90284-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
When intravitreally injected into the frog in vivo, 2-amino-4-phosphonobutyrate (APB) and cis-2,3-piperidine dicarboxylic acid (PDA) showed opposite effects on ON and OFF retinal channels: APB abolished the ON responses in the electroretinogram and in ganglion cell activity, and increased OFF responses. At the same time the receptive field area was enlarged, and the inhibition exerted by the surround was suppressed. A cholinergic/glycinergic loop involving amacrine cells was suggested to be the pathway of the inhibitory ON input upon the OFF channel. PDA abolished the OFF responses in the ERG and in ganglion cell activity, while increasing the ON response in the ERG and decreasing the ganglion cell sensitivity at ON. The receptive field area was not modified, but the inhibition exerted by the surround was suppressed, probably by a blockade of horizontal cell glutamate receptors.
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Affiliation(s)
- B Jardon
- D.N.B.C., Centre de Neurochimie du CNRS, Strasbourg, France
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12
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Abstract
The evidence for the existence of acetylcholine as a neurotransmitter in the vertebrate retina is reviewed. There is evidence for the existence of a cholinergic system in every retina studied to date; therefore, it appears that acetylcholine is both essential and ubiquitous at this level of the visual system. Particular attention is directed to descriptions of the possible functions of acetylcholine in the retina, and formation of testable models which will serve to elucidate some of the details of cholinergic neurotransmission in the retina.
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Affiliation(s)
- J B Hutchins
- Department of Cell Biology, Vanderbilt University School of Medicine, Nashville, TN 37232
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14
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Abstract
Human retinas have the capacity to synthesize and release [3H]acetylcholine ([3H]ACh) after an incubation in [3H]choline ([3H]Ch). Synthesis of [3H]Ch by retinal homogenates was determined using either high-voltage paper electrophoresis (HVPE) or a two-step enzymatic/extraction assay for separating [3H]ACh from [3H]Ch. The enzymatic/extraction assay is shown to be accurate over a wide range of concentrations (10(-6)-10(-12) M). Homogenates of human retina synthesize [3H]ACh from [3H]Ch. We find an approximate Km of 50 microM and a Vmax of about 20 nmol/mg protein/h (at 37 degrees C) for the synthesis of labeled ACh by retinal homogenates. Human retinas also release [3H]ACh after a pulse of [3H]Ch. Release of labeled transmitter is stimulated by potassium depolarization. The potassium-stimulated release is partially blocked by magnesium or cobalt ions. Release data were analyzed by both the enzymatic/extraction assay and HVPE; the results are qualitatively identical in both cases. The data reported here provide additional evidence for cholinergic neurotransmission in the human retina.
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Massey SC, Redburn DA. Light evoked release of acetylcholine in response to a single flash: cholinergic amacrine cells receive ON and OFF input. Brain Res 1985; 328:374-7. [PMID: 2985186 DOI: 10.1016/0006-8993(85)91052-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
By pharmacologically blocking the inhibitory inputs to the cholinergic amacrine cells of the rabbit retina, we have been able to detect the light-evoked release of ACh in response to a single flash. Under these conditions ACh is released equally at light ON and light OFF. This implies that: the cholinergic amacrine cells receive ON and OFF input; they respond to light with depolarizing transients; and the inputs to this system have a basic symmetry.
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Massey SC, Redburn DA, Crawford ML. The effects of 2-amino-4-phosphonobutyric acid (APB) on the ERG and ganglion cell discharge of rabbit retina. Vision Res 1983; 23:1607-13. [PMID: 6666062 DOI: 10.1016/0042-6989(83)90174-8] [Citation(s) in RCA: 88] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Perfusion of 100 microM 2-amino-4-phosphonobutyric acid (APB) into the in vivo rabbit eye-cup selectively and reversibly blocked the b-wave of the ERG and all On responses from retinal ganglion cells. In contrast, Off responses were occasionally enhanced, sometimes dramatically. The antagonistic surround inputs to Off ganglion cells, identified by their latency to light stimulation and magnesium sensitivity, were unchanged by APB. These observations suggest that APB selectively blocks depolarizing bipolar cells in rabbit retina in close agreement with the results of Slaughter and Miller (1981) from mudpuppy retina. We conclude that APB may be useful as a pharmacological tool to differentiate On and Off pathways in the rabbit visual system.
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