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Kim D, Roh H, Lee HM, Kim SJ, Im M. Localization of hyperpolarization-activated cyclic nucleotide-gated channels in the vertebrate retinas across species and their physiological roles. Front Neuroanat 2024; 18:1385932. [PMID: 38562955 PMCID: PMC10982330 DOI: 10.3389/fnana.2024.1385932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Accepted: 03/06/2024] [Indexed: 04/04/2024] Open
Abstract
Transmembrane proteins known as hyperpolarization-activated cyclic nucleotide-gated (HCN) channels control the movement of Na+ and K+ ions across cellular membranes. HCN channels are known to be involved in crucial physiological functions in regulating neuronal excitability and rhythmicity, and pacemaker activity in the heart. Although HCN channels have been relatively well investigated in the brain, their distribution and function in the retina have received less attention, remaining their physiological roles to be comprehensively understood. Also, because recent studies reported HCN channels have been somewhat linked with the dysfunction of photoreceptors which are affected by retinal diseases, investigating HCN channels in the retina may offer valuable insights into disease mechanisms and potentially contribute to identifying novel therapeutic targets for retinal degenerative disorders. This paper endeavors to summarize the existing literature on the distribution and function of HCN channels reported in the vertebrate retinas of various species and discuss the potential implications for the treatment of retinal diseases. Then, we recapitulate current knowledge regarding the function and regulation of HCN channels, as well as their relevance to various neurological disorders.
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Affiliation(s)
- Daniel Kim
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
- Department of Biomedical Sciences, College of Medicine, Seoul National University (SNU), Seoul, Republic of Korea
| | - Hyeonhee Roh
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
- School of Electrical Engineering, College of Engineering, Korea University, Seoul, Republic of Korea
| | - Hyung-Min Lee
- School of Electrical Engineering, College of Engineering, Korea University, Seoul, Republic of Korea
| | - Sang Jeong Kim
- Department of Biomedical Sciences, College of Medicine, Seoul National University (SNU), Seoul, Republic of Korea
| | - Maesoon Im
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
- Division of Bio-Medical Science & Technology, KIST School, University of Science & Technology (UST), Seoul, Republic of Korea
- KHU-KIST Department of Converging Science and Technology, Kyung Hee University, Seoul, Republic of Korea
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Li Q, Cui P, Miao Y, Gao F, Li XY, Qian WJ, Jiang SX, Wu N, Sun XH, Wang Z. Activation of group I metabotropic glutamate receptors regulates the excitability of rat retinal ganglion cells by suppressing Kir and I h. Brain Struct Funct 2016; 222:813-830. [PMID: 27306787 DOI: 10.1007/s00429-016-1248-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 06/05/2016] [Indexed: 10/21/2022]
Abstract
Group I metabotropic glutamate receptor (mGluR I) activation exerts a slow postsynaptic excitatory effect in the CNS. Here, the issues of whether and how this receptor is involved in regulating retinal ganglion cell (RGC) excitability were investigated in retinal slices using patch-clamp techniques. Under physiological conditions, RGCs displayed spontaneous firing. Extracellular application of LY367385 (10 µM)/MPEP (10 µM), selective mGluR1 and mGluR5 antagonists, respectively, significantly reduced the firing frequency, suggesting that glutamate endogenously released from bipolar cells constantly modulates RGC firing. DHPG (10 µM), an mGluR I agonist, significantly increased the firing and caused depolarization of the cells, which were reversed by LY367385, but not by MPEP, suggesting the involvement of the mGluR1 subtype. Intracellular Ca2+-dependent PI-PLC/PKC and calcium/calmodulin-dependent protein kinase II (CaMKII) signaling pathways mediated the DHPG-induced effects. In the presence of cocktail synaptic blockers (CNQX, D-AP5, bicuculline, and strychnine), which terminated the spontaneous firing in both ON and OFF RGCs, DHPG still induced depolarization and triggered the cells to fire. The DHPG-induced depolarization could not be blocked by TTX. In contrast, Ba2+, an inwardly rectifying potassium channel (Kir) blocker, and Cs+ and ZD7288, hyperpolarization-activated cation channel (I h) blockers, mimicked the effect of DHPG. Furthermore, in the presence of Ba2+/ZD7288, DHPG did not show further effects. Moreover, Kir and I h currents could be recorded in RGCs, and extracellular application of DHPG indeed suppressed these currents. Our results suggest that activation of mGluR I regulates the excitability of rat RGCs by inhibiting Kir and I h.
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Affiliation(s)
- Qian Li
- Institutes of Brain Science, Fudan University, 138 Yixueyuan Rd, Shanghai, 200032, China.,Institute of Neurobiology, Fudan University, Shanghai, 200032, China.,State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200032, China.,Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200032, China
| | - Peng Cui
- Institutes of Brain Science, Fudan University, 138 Yixueyuan Rd, Shanghai, 200032, China.,Institute of Neurobiology, Fudan University, Shanghai, 200032, China.,State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200032, China.,Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200032, China
| | - Yanying Miao
- Institutes of Brain Science, Fudan University, 138 Yixueyuan Rd, Shanghai, 200032, China.,Institute of Neurobiology, Fudan University, Shanghai, 200032, China.,State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200032, China.,Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200032, China
| | - Feng Gao
- Institutes of Brain Science, Fudan University, 138 Yixueyuan Rd, Shanghai, 200032, China.,Eye & ENT Hospital, Fudan University, Shanghai, 200031, China.,State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200032, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, 200031, China.,Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200032, China
| | - Xue-Yan Li
- Institutes of Brain Science, Fudan University, 138 Yixueyuan Rd, Shanghai, 200032, China.,Institute of Neurobiology, Fudan University, Shanghai, 200032, China.,State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200032, China.,Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200032, China
| | - Wen-Jing Qian
- Institutes of Brain Science, Fudan University, 138 Yixueyuan Rd, Shanghai, 200032, China.,Institute of Neurobiology, Fudan University, Shanghai, 200032, China.,State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200032, China.,Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200032, China
| | - Shu-Xia Jiang
- Institutes of Brain Science, Fudan University, 138 Yixueyuan Rd, Shanghai, 200032, China.,Institute of Neurobiology, Fudan University, Shanghai, 200032, China.,State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200032, China.,Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200032, China
| | - Na Wu
- Institutes of Brain Science, Fudan University, 138 Yixueyuan Rd, Shanghai, 200032, China.,Eye & ENT Hospital, Fudan University, Shanghai, 200031, China.,State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200032, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, 200031, China.,Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200032, China
| | - Xing-Huai Sun
- Institutes of Brain Science, Fudan University, 138 Yixueyuan Rd, Shanghai, 200032, China. .,Eye & ENT Hospital, Fudan University, Shanghai, 200031, China. .,State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200032, China. .,Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, 200031, China. .,Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200032, China.
| | - Zhongfeng Wang
- Institutes of Brain Science, Fudan University, 138 Yixueyuan Rd, Shanghai, 200032, China. .,Eye & ENT Hospital, Fudan University, Shanghai, 200031, China. .,Institute of Neurobiology, Fudan University, Shanghai, 200032, China. .,State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200032, China. .,Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, 200031, China. .,Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200032, China.
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Pan Y, Bhattarai S, Modestou M, Drack AV, Chetkovich DM, Baker SA. TRIP8b is required for maximal expression of HCN1 in the mouse retina. PLoS One 2014; 9:e85850. [PMID: 24409334 PMCID: PMC3883711 DOI: 10.1371/journal.pone.0085850] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Accepted: 10/31/2013] [Indexed: 01/04/2023] Open
Abstract
Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are cation-selective channels present in retina, brain and heart. The activity of HCN channels contributes to signal integration, cell excitability and pacemaker activity. HCN1 channels expressed in photoreceptors participate in keeping light responses transient and are required for normal mesopic vision. The subcellular localization of HCN1 varies among cell types. In photoreceptors HCN1 is concentrated in the inner segments while in other retinal neurons, HCN1 is evenly distributed though the cell. This is in contrast to hippocampal neurons where HCN1 is concentrated in a subset of dendrites. A key regulator of HCN1 trafficking and activity is tetratricopeptide repeat-containing Rab8b interacting protein (TRIP8b). Multiple splice isoforms of TRIP8b are expressed throughout the brain and can differentially regulate the surface expression and activity of HCN1. The purpose of the present study was to determine which isoforms of TRIP8b are expressed in the retina and to test if loss of TRIP8b alters HCN1 expression or trafficking. We found that TRIP8b colocalizes with HCN1 in multiple retina neurons and all major splice isoforms of TRIP8b are expressed in the retina. Photoreceptors express three different isoforms. In TRIP8b knockout mice, the ability of HCN1 to traffic to the surface of retinal neurons is unaffected. However, there is a large decrease in the total amount of HCN1. We conclude that TRIP8b in the retina is needed to achieve maximal expression of HCN1.
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Affiliation(s)
- Yuan Pan
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Sajag Bhattarai
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Modestos Modestou
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Arlene V. Drack
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Dane M. Chetkovich
- The Ken & Ruth Davee Department of Neurology and Clinical Neurosciences and Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Sheila A. Baker
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- * E-mail:
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Hayashida Y, Rodríguez CV, Ogata G, Partida GJ, Oi H, Stradleigh TW, Lee SC, Colado AF, Ishida AT. Inhibition of adult rat retinal ganglion cells by D1-type dopamine receptor activation. J Neurosci 2009; 29:15001-16. [PMID: 19940196 PMCID: PMC3236800 DOI: 10.1523/jneurosci.3827-09.2009] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Revised: 10/01/2009] [Accepted: 10/22/2009] [Indexed: 11/21/2022] Open
Abstract
The spike output of neural pathways can be regulated by modulating output neuron excitability and/or their synaptic inputs. Dopaminergic interneurons synapse onto cells that route signals to mammalian retinal ganglion cells, but it is unknown whether dopamine can activate receptors in these ganglion cells and, if it does, how this affects their excitability. Here, we show D(1a) receptor-like immunoreactivity in ganglion cells identified in adult rats by retrogradely transported dextran, and that dopamine, D(1)-type receptor agonists, and cAMP analogs inhibit spiking in ganglion cells dissociated from adult rats. These ligands curtailed repetitive spiking during constant current injections and reduced the number and rate of rise of spikes elicited by fluctuating current injections without significantly altering the timing of the remaining spikes. Consistent with mediation by D(1)-type receptors, SCH-23390 [R-(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine] reversed the effects of dopamine on spikes. Contrary to a recent report, spike inhibition by dopamine was not precluded by blocking I(h). Consistent with the reduced rate of spike rise, dopamine reduced voltage-gated Na(+) current (I(Na)) amplitude, and tetrodotoxin, at doses that reduced I(Na) as moderately as dopamine, also inhibited spiking. These results provide the first direct evidence that D(1)-type dopamine receptor activation can alter mammalian retinal ganglion cell excitability and demonstrate that dopamine can modulate spikes in these cells by a mechanism different from the presynaptic and postsynaptic means proposed by previous studies. To our knowledge, our results also provide the first evidence that dopamine receptor activation can reduce excitability without altering the temporal precision of spike firing.
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Affiliation(s)
- Yuki Hayashida
- Departments of Neurobiology, Physiology, and Behavior, and
| | | | - Genki Ogata
- Departments of Neurobiology, Physiology, and Behavior, and
| | | | - Hanako Oi
- Departments of Neurobiology, Physiology, and Behavior, and
| | | | - Sherwin C. Lee
- Departments of Neurobiology, Physiology, and Behavior, and
| | | | - Andrew T. Ishida
- Departments of Neurobiology, Physiology, and Behavior, and
- Ophthalmology and Vision Science, University of California, Davis, Davis, California 95616
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