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Cangiano L, Asteriti S. An Ex Vivo Electroretinographic Apparatus for the mL-Scale Testing of Drugs to One Day and Beyond. Int J Mol Sci 2023; 24:11346. [PMID: 37511106 PMCID: PMC10380068 DOI: 10.3390/ijms241411346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 07/09/2023] [Accepted: 07/10/2023] [Indexed: 07/30/2023] Open
Abstract
When screening new drugs to treat retinal diseases, ex vivo electroretinography (ERG) potentially combines the experimental throughput of its traditional in vivo counterpart, with greater mechanistic insight and reproducible delivery. To date, this technique was used in experiments with open loop superfusion and lasting up to a few hours. Here, we present a compact apparatus that provides continuous and simultaneous recordings of the scotopic a-waves from four mouse retinas for much longer durations. Crucially, each retina can be incubated at 37 °C in only 2 mL of static medium, enabling the testing of very expensive drugs or nano devices. Light sensitivity and response kinetics of these preparations remain in the physiological range throughout incubation, displaying only very slow drifts. As an example application, we showed that barium, a potassium channel blocker used to abolish the glial component of the ERG, displayed no overt side effects on photoreceptors over several hours. In another example, we fully regenerated a partially bleached retina using a minimal quantity of 9-cis-retinal. Finally, we demonstrated that including antibiotic in the incubation medium extends physiological light responses to over one day. This system represents a necessary stepping stone towards the goal of combining ERG recordings with organotypically cultured retinas.
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Affiliation(s)
- Lorenzo Cangiano
- Department of Translational Research, University of Pisa, 56123 Pisa, Italy
| | - Sabrina Asteriti
- Department of Translational Research, University of Pisa, 56123 Pisa, Italy
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, 37134 Verona, Italy
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2
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Gabriel E, Albanna W, Pasquini G, Ramani A, Josipovic N, Mariappan A, Riparbelli MG, Callaini G, Karch CM, Goureau O, Papantonis A, Busskamp V, Schneider T, Gopalakrishnan J. Generation of iPSC-derived human forebrain organoids assembling bilateral eye primordia. Nat Protoc 2023:10.1038/s41596-023-00814-x. [PMID: 37198320 DOI: 10.1038/s41596-023-00814-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 01/13/2023] [Indexed: 05/19/2023]
Abstract
Induced pluripotent stem cell-derived brain organoids enable the developmental complexities of the human brain to be deconstructed. During embryogenesis, optic vesicles (OVs), the eye primordium attached to the forebrain, develop from diencephalon. However, most 3D culturing methods generate either brain or retinal organoids individually. Here we describe a protocol to generate organoids with both forebrain entities, which we call OV-containing brain organoids (OVB organoids). In this protocol, we first induce neural differentiation (days 0-5) and collect neurospheres, which we culture in a neurosphere medium to initiate their patterning and further self-assembly (days 5-10). Then, upon transfer to spinner flasks containing OVB medium (days 10-30), neurospheres develop into forebrain organoids with one or two pigmented dots restricted to one pole, displaying forebrain entities of ventral and dorsal cortical progenitors and preoptic areas. Further long-term culture results in photosensitive OVB organoids constituting complementary cell types of OVs, including primitive corneal epithelial and lens-like cells, retinal pigment epithelia, retinal progenitor cells, axon-like projections and electrically active neuronal networks. OVB organoids provide a system to help dissect interorgan interactions between the OVs as sensory organs and the brain as a processing unit, and can help model early eye patterning defects, including congenital retinal dystrophy. To conduct the protocol, experience in sterile cell culture and maintenance of human induced pluripotent stem cells is essential; theoretical knowledge of brain development is advantageous. Furthermore, specialized expertise in 3D organoid culture and imaging for the analysis is needed.
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Affiliation(s)
- Elke Gabriel
- Institute of Human Genetics, University Hospital, Heinrich-Heine-University, Düsseldorf, Germany
| | - Walid Albanna
- Institute for Neurophysiology, University of Cologne, Cologne, Germany
- Department of Neurosurgery, RWTH Aachen University, Aachen, Germany
| | - Giovanni Pasquini
- Department of Ophthalmology, Medical Faculty, University of Bonn, Bonn, Germany
| | - Anand Ramani
- Institute of Human Genetics, University Hospital, Heinrich-Heine-University, Düsseldorf, Germany
| | - Natasa Josipovic
- Institute of Pathology, University Medicine Göttingen, Georg-August University Göttingen, Göttingen, Germany
- Center of Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Aruljothi Mariappan
- Institute of Human Genetics, University Hospital, Heinrich-Heine-University, Düsseldorf, Germany
| | | | - Giuliano Callaini
- Department of Life Sciences and Medical Biotechnology University of Siena, Siena, Italy
| | - Celeste M Karch
- Department of Psychiatry, Washington University in St. Louis, St. Louis, MO, USA
| | - Olivier Goureau
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France
| | - Argyris Papantonis
- Institute of Pathology, University Medicine Göttingen, Georg-August University Göttingen, Göttingen, Germany
- Center of Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Volker Busskamp
- Department of Ophthalmology, Medical Faculty, University of Bonn, Bonn, Germany
| | - Toni Schneider
- Institute for Neurophysiology, University of Cologne, Cologne, Germany
| | - Jay Gopalakrishnan
- Institute of Human Genetics, University Hospital, Heinrich-Heine-University, Düsseldorf, Germany.
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3
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Gabriel E, Albanna W, Pasquini G, Ramani A, Josipovic N, Mariappan A, Schinzel F, Karch CM, Bao G, Gottardo M, Suren AA, Hescheler J, Nagel-Wolfrum K, Persico V, Rizzoli SO, Altmüller J, Riparbelli MG, Callaini G, Goureau O, Papantonis A, Busskamp V, Schneider T, Gopalakrishnan J. Human brain organoids assemble functionally integrated bilateral optic vesicles. Cell Stem Cell 2021; 28:1740-1757.e8. [PMID: 34407456 DOI: 10.1016/j.stem.2021.07.010] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 04/23/2021] [Accepted: 07/20/2021] [Indexed: 02/07/2023]
Abstract
During embryogenesis, optic vesicles develop from the diencephalon via a multistep process of organogenesis. Using induced pluripotent stem cell (iPSC)-derived human brain organoids, we attempted to simplify the complexities and demonstrate formation of forebrain-associated bilateral optic vesicles, cellular diversity, and functionality. Around day 30, brain organoids attempt to assemble optic vesicles, which develop progressively as visible structures within 60 days. These optic vesicle-containing brain organoids (OVB-organoids) constitute a developing optic vesicle's cellular components, including primitive corneal epithelial and lens-like cells, retinal pigment epithelia, retinal progenitor cells, axon-like projections, and electrically active neuronal networks. OVB-organoids also display synapsin-1, CTIP-positive myelinated cortical neurons, and microglia. Interestingly, various light intensities could trigger photosensitive activity of OVB-organoids, and light sensitivities could be reset after transient photobleaching. Thus, brain organoids have the intrinsic ability to self-organize forebrain-associated primitive sensory structures in a topographically restricted manner and can allow interorgan interaction studies within a single organoid.
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Affiliation(s)
- Elke Gabriel
- Institute of Human Genetics, University Hospital, Heinrich-Heine-Universität, 40225 Düsseldorf, Germany
| | - Walid Albanna
- Institute for Neurophysiology, University of Cologne, 50931 Cologne, Germany; Department of Neurosurgery, RWTH Aachen University, 52074 Aachen, Germany
| | - Giovanni Pasquini
- Department of Ophthalmology, Medical Faculty, University of Bonn, Bonn, Germany
| | - Anand Ramani
- Institute of Human Genetics, University Hospital, Heinrich-Heine-Universität, 40225 Düsseldorf, Germany
| | - Natasa Josipovic
- Institute of Pathology, University Medicine Göttingen, Georg-August University Göttingen, 37075 Göttingen, Germany; Center for molecular medicine, Cologne, Universität zu Köln, 50931 Köln, Germany
| | - Aruljothi Mariappan
- Institute of Human Genetics, University Hospital, Heinrich-Heine-Universität, 40225 Düsseldorf, Germany
| | - Friedrich Schinzel
- Institute of Human Genetics, University Hospital, Heinrich-Heine-Universität, 40225 Düsseldorf, Germany
| | - Celeste M Karch
- Department of Psychiatry, Washington University in St. Louis, St. Louis, MO 63116, USA
| | - Guobin Bao
- Institute of Neurophysiology and Cellular Biophysics, University Medicine Göttingen, Georg-August-Universität Göttingen, 37073 Göttingen, Germany
| | - Marco Gottardo
- Institute of Human Genetics, University Hospital, Heinrich-Heine-Universität, 40225 Düsseldorf, Germany
| | - Ata Alp Suren
- Institute of Human Genetics, University Hospital, Heinrich-Heine-Universität, 40225 Düsseldorf, Germany
| | - Jürgen Hescheler
- Institute for Neurophysiology, University of Cologne, 50931 Cologne, Germany
| | - Kerstin Nagel-Wolfrum
- Institute of Molecular Physiology, Johannes Gutenberg University, 55099 Mainz, Germany
| | - Veronica Persico
- Department of Life Sciences and Medical Biotechnology University of Siena, Siena 53100, Italy
| | - Silvio O Rizzoli
- Institute of Neurophysiology and Cellular Biophysics, University Medicine Göttingen, Georg-August-Universität Göttingen, 37073 Göttingen, Germany
| | - Janine Altmüller
- Cologne Center for Genomics (CCG), Universität zu Köln, Köln, Germany; Center for molecular medicine, Cologne, Universität zu Köln, 50931 Köln, Germany
| | | | - Giuliano Callaini
- Department of Life Sciences and Medical Biotechnology University of Siena, Siena 53100, Italy
| | - Olivier Goureau
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, 75012 Paris, France
| | - Argyris Papantonis
- Institute of Pathology, University Medicine Göttingen, Georg-August University Göttingen, 37075 Göttingen, Germany
| | - Volker Busskamp
- Department of Ophthalmology, Medical Faculty, University of Bonn, Bonn, Germany
| | - Toni Schneider
- Institute for Neurophysiology, University of Cologne, 50931 Cologne, Germany
| | - Jay Gopalakrishnan
- Institute of Human Genetics, University Hospital, Heinrich-Heine-Universität, 40225 Düsseldorf, Germany.
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4
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Lüke JN, Neumaier F, Alpdogan S, Hescheler J, Schneider T, Albanna W, Akhtar-Schäfer I. Submicromolar copper (II) ions stimulate transretinal signaling in the isolated retina from wild type but not from Ca v2.3-deficient mice. BMC Ophthalmol 2020; 20:182. [PMID: 32375703 PMCID: PMC7201970 DOI: 10.1186/s12886-020-01451-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 04/24/2020] [Indexed: 05/30/2023] Open
Abstract
BACKGROUND So far, only indirect evidence exists for the pharmacoresistant R-type voltage-gated Ca2+ channel (VGCC) to be involved in transretinal signaling by triggering GABA-release onto ON-bipolar neurons. This release of inhibitory neurotransmitters was deduced from the sensitivity of the b-wave to stimulation by Ni2+, Zn2+ and Cu2+. To further confirm the interpretation of these findings, we compared the effects of Cu2+ application and chelation (using kainic acid, KA) on the neural retina from wildtype and Cav2.3-deficient mice. Furthermore, the immediately effect of KA on the ERG b-wave modulation was assessed. METHODS Transretinal signaling was recorded as an ERG from the superfused murine retina isolated from wildtype and Cav2.3-deficient mice. RESULTS In mice, the stimulating effect of 100 nM CuCl2 is absent in the retinae from Cav2.3-deficient mice, but prominent in Cav2.3-competent mice. Application of up to 3 mM tricine does not affect the murine b-wave in both genotypes, most likely because of chelating amino acids present in the murine nutrient solution. Application of 27 μM KA significantly increased the b-wave amplitude in wild type and Cav2.3 (-|-) mice. This effect can most likely be explained by the stimulation of endogenous KA-receptors described in horizontal, OFF-bipolar, amacrine or ganglion cells, which could not be fully blocked in the present study. CONCLUSION Cu2+-dependent modulation of transretinal signaling only occurs in the murine retina from Cav2.3 competent mice, supporting the ideas derived from previous work in the bovine retina that R-type Ca2+ channels are involved in shaping transretinal responses during light perception.
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Affiliation(s)
- Jan Niklas Lüke
- Institute for Neurophysiology, University of Cologne, Robert-Koch Str. 39, D-50931, Cologne, Germany
| | - Felix Neumaier
- Institute for Neurophysiology, University of Cologne, Robert-Koch Str. 39, D-50931, Cologne, Germany
| | - Serdar Alpdogan
- Institute for Neurophysiology, University of Cologne, Robert-Koch Str. 39, D-50931, Cologne, Germany
| | - Jürgen Hescheler
- Institute for Neurophysiology, University of Cologne, Robert-Koch Str. 39, D-50931, Cologne, Germany
| | - Toni Schneider
- Institute for Neurophysiology, University of Cologne, Robert-Koch Str. 39, D-50931, Cologne, Germany.
| | - Walid Albanna
- Institute for Neurophysiology, University of Cologne, Robert-Koch Str. 39, D-50931, Cologne, Germany. .,Department of Neurosurgery, University Hospital, RWTH Aachen, Aachen, Germany.
| | - Isha Akhtar-Schäfer
- Institute for Neurophysiology, University of Cologne, Robert-Koch Str. 39, D-50931, Cologne, Germany
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5
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Modulation of Ca v2.3 channels by unconjugated bilirubin (UCB) - Candidate mechanism for UCB-induced neuromodulation and neurotoxicity. Mol Cell Neurosci 2019; 96:35-46. [PMID: 30877033 DOI: 10.1016/j.mcn.2019.03.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2018] [Revised: 12/15/2018] [Accepted: 03/10/2019] [Indexed: 11/23/2022] Open
Abstract
Elevated levels of unbound unconjugated bilirubin (UCB) can lead to bilirubin encephalopathy and kernicterus. In spite of a large number of studies demonstrating UCB-induced changes in central neurotransmission, it is still unclear whether these effects involve alterations in the function of specific ion channels. To assess how different UCB concentrations and UCB:albumin (U/A) molar ratios affect neuronal R-type voltage-gated Ca2+ channels, we evaluated their effects on whole-cell currents through recombinant Cav2.3 + β3 channel complexes and ex-vivo electroretinograms (ERGs) from wildtype and Cav2.3-deficient mice. Our findings show that modestly elevated levels of unbound UCB (U/A = 0.5) produce subtle but significant changes in the voltage-dependence of activation and prepulse inactivation, resulting in a stimulation of currents activated by weak depolarization and inhibition at potentials on the plateau of the activation curve. Saturation of the albumin binding capacity (U/A = 1) produced additional suppression that became significant when albumin was omitted completely and might involve a complete loss of channel function. Acutely administered UCB (U/A = 0.5) has recently been shown to affect transsynaptic signaling in the isolated vertebrate retina. The present report reveals that sustained exposure of the murine retina to UCB significantly suppresses also late responses of the inner retina (b-wave) from wildtype compared to Cav2.3-deficient mice. In addition, recovery during washout was significantly more complete and faster in retinae lacking Cav2.3 channels. Together, these findings show that UCB affects cloned and native Cav2.3 channels at clinically relevant U/A molar ratios and indicate that supersaturation of albumin is not required for modulation but associated with a loss of channel functional that could contribute to chronic neuronal dysfunction.
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6
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Albanna W, Kotliar K, Lüke JN, Alpdogan S, Conzen C, Lindauer U, Clusmann H, Hescheler J, Vilser W, Schneider T, Schubert GA. Non-invasive evaluation of neurovascular coupling in the murine retina by dynamic retinal vessel analysis. PLoS One 2018; 13:e0204689. [PMID: 30286110 PMCID: PMC6171857 DOI: 10.1371/journal.pone.0204689] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Accepted: 09/11/2018] [Indexed: 11/22/2022] Open
Abstract
Background Impairment of neurovascular coupling (NVC) was recently reported in the context of subarachnoid hemorrhage and may correlate with disease severity and outcome. However, previous techniques to evaluate NVC required invasive procedures. Retinal vessels may represent an alternative option for non-invasive assessment of NVC. Methods A prototype of an adapted retinal vessel analyzer was used to assess retinal vessel diameter in mice. Dynamic vessel analysis (DVA) included an application of monochromatic flicker light impulses in predefined frequencies for evaluating NVC. All retinae were harvested after DVA and electroretinograms were performed. Results A total of 104 retinal scans were conducted in 21 male mice (90 scans). Quantitative arterial recordings were feasible only in a minority of animals, showing an emphasized reaction to flicker light impulses (8 mice; 14 scans). A characteristic venous response to flicker light, however, could observed in the majority of animals. Repeated measurements resulted in a significant decrease of baseline venous diameter (7 mice; 7 scans, p < 0.05). Ex-vivo electroretinograms, performed after in-vivo DVA, demonstrated a significant reduction of transretinal signaling in animals with repeated DVA (n = 6, p < 0.001). Conclusions To the best of our knowledge, this is the first non-invasive study assessing murine retinal vessel response to flicker light with characteristic changes in NVC. The imaging system can be used for basic research and enables the investigation of retinal vessel dimension and function in control mice and genetically modified animals.
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Affiliation(s)
- Walid Albanna
- Institute for Neurophysiology, University of Cologne, Cologne, Germany
- Department of Neurosurgery, RWTH Aachen University, Aachen, Germany
- * E-mail:
| | - Konstantin Kotliar
- Department of Medical Engineering and Technomathematics, FH Aachen University of Applied Sciences, Aachen, Germany
| | - Jan Niklas Lüke
- Institute for Neurophysiology, University of Cologne, Cologne, Germany
| | - Serdar Alpdogan
- Institute for Neurophysiology, University of Cologne, Cologne, Germany
| | - Catharina Conzen
- Department of Neurosurgery, RWTH Aachen University, Aachen, Germany
| | - Ute Lindauer
- Department of Neurosurgery, RWTH Aachen University, Aachen, Germany
- Tranlational Neurosurgery and Neurobiology, RWTH Aachen University, Aachen, Germany
| | - Hans Clusmann
- Department of Neurosurgery, RWTH Aachen University, Aachen, Germany
| | - Jürgen Hescheler
- Institute for Neurophysiology, University of Cologne, Cologne, Germany
| | | | - Toni Schneider
- Institute for Neurophysiology, University of Cologne, Cologne, Germany
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7
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Neumaier F, Akhtar-Schäfer I, Lüke JN, Dibué-Adjei M, Hescheler J, Schneider T. Reciprocal modulation of Ca v 2.3 voltage-gated calcium channels by copper(II) ions and kainic acid. J Neurochem 2018; 147:310-322. [PMID: 29972687 DOI: 10.1111/jnc.14546] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 06/11/2018] [Accepted: 07/02/2018] [Indexed: 12/31/2022]
Abstract
Kainic acid (KA) is a potent agonist at non-N-methyl-D-aspartate (non-NMDA) ionotropic glutamate receptors and commonly used to induce seizures and excitotoxicity in animal models of human temporal lobe epilepsy. Among other factors, Cav 2.3 voltage-gated calcium channels have been implicated in the pathogenesis of KA-induced seizures. At physiologically relevant concentrations, endogenous trace metal ions (Cu2+ , Zn2+ ) occupy an allosteric binding site on the domain I gating module of these channels and interfere with voltage-dependent gating. Using whole-cell patch-clamp recordings in human embryonic kidney (HEK-293) cells stably transfected with human Cav 2.3d and β3 -subunits, we identified a novel, glutamate receptor-independent mechanism by which KA can potently sensitize these channels. Our findings demonstrate that KA releases these channels from the tonic inhibition exerted by low nanomolar concentrations of Cu2+ and produces a hyperpolarizing shift in channel voltage-dependence by about 10 mV, thereby reconciling the effects of Cu2+ chelation with tricine. When tricine was used as a surrogate to study the receptor-independent action of KA in electroretinographic recordings from the isolated bovine retina, it selectively suppressed a late b-wave component, which we have previously shown to be enhanced by genetic or pharmacological ablation of Cav 2.3 channels. Although the pathophysiological relevance remains to be firmly established, we speculate that reversal of Cu2+ -induced allosteric suppression, presumably via formation of stable kainate-Cu2+ complexes, could contribute to the receptor-mediated excitatory effects of KA. In addition, we discuss experimental implications for the use of KA in vitro, with particular emphasis on the seemingly high incidence of trace metal contamination in common physiological solutions.
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Affiliation(s)
- Felix Neumaier
- Institute for Neurophysiology, University of Cologne, Cologne, Germany
| | - Isha Akhtar-Schäfer
- Institute for Neurophysiology, University of Cologne, Cologne, Germany.,Department of Ophthalmology, Laboratory for Experimental Immunology of the Eye, University of Cologne, Cologne, Germany
| | - Jan Niklas Lüke
- Institute for Neurophysiology, University of Cologne, Cologne, Germany
| | - Maxine Dibué-Adjei
- Institute for Neurophysiology, University of Cologne, Cologne, Germany.,Department for Neurosurgery, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Jürgen Hescheler
- Institute for Neurophysiology, University of Cologne, Cologne, Germany
| | - Toni Schneider
- Institute for Neurophysiology, University of Cologne, Cologne, Germany
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8
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Albanna W, Neumaier F, Lüke JN, Kotliar K, Conzen C, Lindauer U, Hescheler J, Clusmann H, Schneider T, Schubert GA. Unconjugated bilirubin modulates neuronal signaling only in wild-type mice, but not after ablation of the R-type/Ca v 2.3 voltage-gated calcium channel. CNS Neurosci Ther 2017; 24:222-230. [PMID: 29274300 DOI: 10.1111/cns.12791] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 12/04/2017] [Accepted: 12/04/2017] [Indexed: 01/30/2023] Open
Abstract
INTRODUCTION The relationship between blood metabolites and hemoglobin degradation products (BMHDPs) formed in the cerebrospinal fluid and the development of vasospasm and delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH) has been the focus of several previous studies, but their molecular and cellular targets remain to be elucidated. METHODS Because BMHDP-induced changes in Cav 2.3 channel function are thought to contribute to DCI after aSAH, we studied their modulation by unconjugated bilirubin (UCB) in an organotypical neuronal network from wild-type (WT) and Cav 2.3-deficient animals (KO). Murine retinae were isolated from WT and KO and superfused with nutrient solution. Electroretinograms were recorded before, during, and after superfusion with UCB. Transretinal signaling was analyzed as b-wave, implicit time, and area under the curve (AUC). RESULTS Superfusion of UCB significantly attenuated the b-wave amplitude in the isolated retina from wild-type mice by 14.9% (P < 0.05), followed by gradual partial recovery (P = 0.09). Correspondingly, AUC decreased significantly with superfusion of UCB (P < 0.05). During washout, the b-wave amplitude returned to baseline (P = 0.2839). The effects of UCB were absent in Cav 2.3-deficient mice, lacking the expression of Cav 2.3 as proofed on the biochemical level. CONCLUSIONS Ex vivo neuronal recording in the murine retina is able to detect transient impairment of transretinal signaling by UCB in WT, but not in KO. This new model may be useful to further clarify the role of calcium channels in neuronal signal alteration in the presence of BHMDPs.
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Affiliation(s)
- Walid Albanna
- Institute for Neurophysiology, University of Cologne, Cologne, Germany.,Department of Neurosurgery, RWTH Aachen University, Aachen, Germany
| | - Felix Neumaier
- Institute for Neurophysiology, University of Cologne, Cologne, Germany
| | - Jan Niklas Lüke
- Institute for Neurophysiology, University of Cologne, Cologne, Germany
| | - Konstantin Kotliar
- Department of Medical Engineering and Technomathematics, FH Aachen University of Applied Sciences, Aachen, Germany
| | - Catharina Conzen
- Department of Neurosurgery, RWTH Aachen University, Aachen, Germany
| | - Ute Lindauer
- Department of Neurosurgery, RWTH Aachen University, Aachen, Germany
| | - Jürgen Hescheler
- Institute for Neurophysiology, University of Cologne, Cologne, Germany
| | - Hans Clusmann
- Department of Neurosurgery, RWTH Aachen University, Aachen, Germany
| | - Toni Schneider
- Institute for Neurophysiology, University of Cologne, Cologne, Germany
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9
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Tikidji-Hamburyan A, Reinhard K, Storchi R, Dietter J, Seitter H, Davis KE, Idrees S, Mutter M, Walmsley L, Bedford RA, Ueffing M, Ala-Laurila P, Brown TM, Lucas RJ, Münch TA. Rods progressively escape saturation to drive visual responses in daylight conditions. Nat Commun 2017; 8:1813. [PMID: 29180667 PMCID: PMC5703729 DOI: 10.1038/s41467-017-01816-6] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 10/18/2017] [Indexed: 12/21/2022] Open
Abstract
Rod and cone photoreceptors support vision across large light intensity ranges. Rods, active under dim illumination, are thought to saturate at higher (photopic) irradiances. The extent of rod saturation is not well defined; some studies report rod activity well into the photopic range. Using electrophysiological recordings from retina and dorsal lateral geniculate nucleus of cone-deficient and visually intact mice, we describe stimulus and physiological factors that influence photopic rod-driven responses. We find that rod contrast sensitivity is initially strongly reduced at high irradiances, but progressively recovers to allow responses to moderate contrast stimuli. Surprisingly, rods recover faster at higher light levels. A model of rod phototransduction suggests that phototransduction gain adjustments and bleaching adaptation underlie rod recovery. Consistently, exogenous chromophore reduces rod responses at bright background. Thus, bleaching adaptation renders mouse rods responsive to modest contrast at any irradiance. Paradoxically, raising irradiance across the photopic range increases the robustness of rod responses. Rod photoreceptors are thought to be saturated under bright light. Here, the authors describe the physiological parameters that mediate response saturation of rod photoreceptors in mouse retina, and show that rods can drive visual responses in photopic conditions.
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Affiliation(s)
- Alexandra Tikidji-Hamburyan
- Retinal Circuits and Optogenetics, Centre for Integrative Neuroscience and Bernstein Center for Computational Neuroscience, University of Tübingen, 72076, Tübingen, Germany.,International Max Planck Research School, University of Tübingen, 72074, Tübingen, Germany.,Department of Neurosurgery and Hansen Experimental Physics Laboratory, Stanford University, Stanford, California, 94305-4085, USA
| | - Katja Reinhard
- Retinal Circuits and Optogenetics, Centre for Integrative Neuroscience and Bernstein Center for Computational Neuroscience, University of Tübingen, 72076, Tübingen, Germany.,International Max Planck Research School, University of Tübingen, 72074, Tübingen, Germany.,Visual Circuits Laboratory, Neuro-Electronics Research Flanders, IMEC, KU Leuven and VIB, 3001, Leuven, Belgium
| | - Riccardo Storchi
- Faculty of Biology Medicine and Health, University of Manchester, Manchester, M13 9PT, UK
| | - Johannes Dietter
- Institute for Ophthalmic Research, Department of Ophthalmology, University of Tübingen, 72076, Tübingen, Germany
| | - Hartwig Seitter
- Retinal Circuits and Optogenetics, Centre for Integrative Neuroscience and Bernstein Center for Computational Neuroscience, University of Tübingen, 72076, Tübingen, Germany.,International Max Planck Research School, University of Tübingen, 72074, Tübingen, Germany.,Institute of Pharmacy, Department of Pharmacology and Toxicology, University of Innsbruck, A-6020, Innsbruck, Austria
| | - Katherine E Davis
- Faculty of Biology Medicine and Health, University of Manchester, Manchester, M13 9PT, UK
| | - Saad Idrees
- Retinal Circuits and Optogenetics, Centre for Integrative Neuroscience and Bernstein Center for Computational Neuroscience, University of Tübingen, 72076, Tübingen, Germany.,International Max Planck Research School, University of Tübingen, 72074, Tübingen, Germany
| | - Marion Mutter
- Retinal Circuits and Optogenetics, Centre for Integrative Neuroscience and Bernstein Center for Computational Neuroscience, University of Tübingen, 72076, Tübingen, Germany.,International Max Planck Research School, University of Tübingen, 72074, Tübingen, Germany
| | - Lauren Walmsley
- Faculty of Biology Medicine and Health, University of Manchester, Manchester, M13 9PT, UK
| | - Robert A Bedford
- Faculty of Biology Medicine and Health, University of Manchester, Manchester, M13 9PT, UK.,Stryker Imorphics, Worthington House, Towers Business Park, Wilmslow Road, Manchester, M20 2HJ, UK
| | - Marius Ueffing
- Institute for Ophthalmic Research, Department of Ophthalmology, University of Tübingen, 72076, Tübingen, Germany
| | - Petri Ala-Laurila
- Department of Biosciences, University of Helsinki, 00014, Helsinki, Finland.,Department of Neuroscience and Biomedical Engineering (NBE), Aalto University School of Science and Technology, 00076, Espoo, Finland
| | - Timothy M Brown
- Faculty of Biology Medicine and Health, University of Manchester, Manchester, M13 9PT, UK
| | - Robert J Lucas
- Faculty of Biology Medicine and Health, University of Manchester, Manchester, M13 9PT, UK.
| | - Thomas A Münch
- Retinal Circuits and Optogenetics, Centre for Integrative Neuroscience and Bernstein Center for Computational Neuroscience, University of Tübingen, 72076, Tübingen, Germany. .,Institute for Ophthalmic Research, Department of Ophthalmology, University of Tübingen, 72076, Tübingen, Germany.
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