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Eom K, Jung J, Kim B, Hyun JH. Molecular tools for recording and intervention of neuronal activity. Mol Cells 2024; 47:100048. [PMID: 38521352 PMCID: PMC11021360 DOI: 10.1016/j.mocell.2024.100048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 03/12/2024] [Accepted: 03/17/2024] [Indexed: 03/25/2024] Open
Abstract
Observing the activity of neural networks is critical for the identification of learning and memory processes, as well as abnormal activities of neural circuits in disease, particularly for the purpose of tracking disease progression. Methodologies for describing the activity history of neural networks using molecular biology techniques first utilized genes expressed by active neurons, followed by the application of recently developed techniques including optogenetics and incorporation of insights garnered from other disciplines, including chemistry and physics. In this review, we will discuss ways in which molecular biological techniques used to describe the activity of neural networks have evolved along with the potential for future development.
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Affiliation(s)
- Kisang Eom
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea
| | - Jinhwan Jung
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea
| | - Byungsoo Kim
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea
| | - Jung Ho Hyun
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea; Center for Synapse Diversity and Specificity, DGIST, Daegu 42988, Republic of Korea.
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Lim DM, Lee H, Eom K, Kim YH, Kim S. Bioinformatic analysis of the obesity paradox and possible associated factors in colorectal cancer using TCGA cohorts. J Cancer 2023; 14:322-335. [PMID: 36860923 PMCID: PMC9969588 DOI: 10.7150/jca.80977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 01/07/2023] [Indexed: 02/04/2023] Open
Abstract
Colorectal cancer (CRC) is a common malignancy worldwide and the second leading cause of cancer-related deaths. Obesity is an important determinant of CRC incidence; however, obese patients have also shown better long-term survival than non-obese patients, suggesting that the development and progression of CRC are associated with different mechanisms. This study compares the expression of genes, tumor-infiltrating immune cells, and intestinal microbiota between high- and low-body mass index (BMI) patients at the time of CRC diagnosis. The results revealed that high-BMI patients with CRC have better prognosis, higher levels of resting CD4+ T cells, lower levels of T follicular helper cells, and different levels of intratumoral microbiota than low-BMI patients. Our study highlights that tumor-infiltrating immune cells and intratumoral microbe diversity are major features of the obesity paradox in CRC.
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Affiliation(s)
- Dong Min Lim
- Interdisciplinary Program of Genomic Data Science, Pusan National University, Yangsan 50612, Korea
| | - Hyunsu Lee
- Department of Medical Informatics, School of Medicine, Keimyung University, 1095 Dalgubeol-daero, Dalseo-gu, Daegu 42601, Republic of Korea
| | - Kisang Eom
- Department of Physiology, School of Medicine, Keimyung University, 1095 Dalgubeol-daero, Dalseo-gu, Daegu 42601, Republic of Korea
| | - Yun Hak Kim
- Department of Biomedical Informatics, School of Medicine, Pusan National University, Yangsan 50612, Republic of Korea.,Department of Anatomy, School of Medicine, Pusan National University, Yangsan 50612, Korea.,✉ Corresponding authors: Shin Kim, M.D., Ph.D. Department of Immunology, School of Medicine, Keimyung University, Dalseo-gu, Daegu 42601, Republic of Korea. TEL: +82-53-258-7359; Fax: +82-53-258-7355; E-mail: ; Yun Hak Kim, M.D., Ph.D. Department of Anatomy, School of Medicine, Pusan National University, Yangsan 50612, Korea. TEL: +82-51-510-8091; Fax: +82-51-510-8049; E-mail:
| | - Shin Kim
- Department of Immunology, School of Medicine, Keimyung University, Dalseo-gu, Daegu 42601, Republic of Korea.,Institute of Medical Science, Keimyung University, Dalseo-gu, Daegu 42601, Republic of Korea.,Institute for Cancer Research, Keimyung University Dongsan Medical Center, Dalseo-gu, Daegu 42601, Republic of Korea.,✉ Corresponding authors: Shin Kim, M.D., Ph.D. Department of Immunology, School of Medicine, Keimyung University, Dalseo-gu, Daegu 42601, Republic of Korea. TEL: +82-53-258-7359; Fax: +82-53-258-7355; E-mail: ; Yun Hak Kim, M.D., Ph.D. Department of Anatomy, School of Medicine, Pusan National University, Yangsan 50612, Korea. TEL: +82-51-510-8091; Fax: +82-51-510-8049; E-mail:
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Eom K. Partial EC outputs by degraded cues are amplified in hippocampal CA3 circuits for retrieving stored patterns. PLoS One 2023; 18:e0281458. [PMID: 37075035 PMCID: PMC10115257 DOI: 10.1371/journal.pone.0281458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 01/24/2023] [Indexed: 04/20/2023] Open
Abstract
Hippocampus is known to be important for episodic memories. Measuring of hippocampal neural ensembles is therefore important for observing hippocampal cognitive processes such as pattern completion. Previous studies on pattern completion had a limitation because the activities of CA3 were not simultaneously observed with the activities of the entorhinal cortex that project to the CA3. In addition, in previous research and modelling, distinct concepts such as pattern completion and pattern convergence have not been considered separately. Here, I used a molecular analysis technique that enables comparison of neural ensembles that evoked two successive events and evaluated neural ensembles in the hippocampal CA3 region and entorhinal cortex. By comparing neural ensembles in hippocampus and entorhinal cortex, I could obtain evidence that suggests pattern completion occurring in the CA3 region was induced by the partial input from EC. Use of the molecular-based ensemble measurement allows measuring two or more brain regions simultaneously, which can lead to insights into the cognitive functions of neural circuits.
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Affiliation(s)
- Kisang Eom
- Department of Physiology, School of Medicine, Keimyung University, Dalseogu District, Daegu Metropolitan City, Republic of Korea
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Kim HH, Lee SH, Ho WK, Eom K. Dopamine Receptor Supports the Potentiation of Intrinsic Excitability and Synaptic LTD in Temporoammonic-CA1 Synapse. Exp Neurobiol 2022; 31:361-375. [PMID: 36631845 PMCID: PMC9841748 DOI: 10.5607/en22028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 11/15/2022] [Accepted: 12/28/2022] [Indexed: 01/13/2023] Open
Abstract
Dopaminergic projection to the hippocampus from the ventral tegmental area or locus ceruleus has been considered to play an essential role in the acquisition of novel information. Hence, the dopaminergic modulation of synaptic plasticity in the hippocampus has been widely studied. We examined how the D1 and D2 receptors influenced the mGluR5-mediated synaptic plasticity of the temporoammonic-CA1 synapses and showed that the dopaminergic modulation of the temporoammonic-CA1 synapses was expressed in various ways. Our findings suggest that the dopaminergic system in the hippocampal CA1 region regulates the long-term synaptic plasticity and processing of the novel information.
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Affiliation(s)
- Hye-Hyun Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea,Neuroscience Research Center, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Suk-Ho Lee
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea,Neuroscience Research Center, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Won-Kyung Ho
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea,Neuroscience Research Center, Seoul National University College of Medicine, Seoul 03080, Korea,Won-Kyung Ho, TEL: 82-2-740-8226, FAX: 82-2-763-9667, e-mail:
| | - Kisang Eom
- Department of Physiology, School of Medicine, Keimyung University, Daegu 42601, Korea,To whom correspondence should be addressed. Kisang Eom, TEL: 82-53-258-7416, FAX: 82-53-258-7412, e-mail:
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Eom K, Lee HR. Measuring Pattern Separation in Hippocampus by in Situ Hybridization. Curr Protoc 2022; 2:e522. [PMID: 35980141 DOI: 10.1002/cpz1.522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Distinguishing different contexts is thought to involve a form of pattern separation that minimizes overlap between neural ensembles representing similar experiences. Theoretical models suggest that the dentate gyrus (DG) segregates cortical input patterns before relaying its discriminated output patterns to the CA3 hippocampal field. This suggests that the evaluation of neural ensembles in DG and CA3 could be an important means to investigate the process of pattern separation. In the past, measurement of entorhinal cortex (EC), DG, and CA3 ensembles was largely dependent upon in vivo electrophysiological recording, which is technically difficult. This protocol provides a method to instead measure pattern separation by a molecular method that provides direct spatial resolution at the cellular level. © 2022 Wiley Periodicals LLC. Basic Protocol: Measuring pattern separation by molecular methods.
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Affiliation(s)
- Kisang Eom
- Department of Physiology, Keimyung University, School of Medicine, Daegu, Republic of Korea
| | - Hyoung-Ro Lee
- Cell Physiology Lab., Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
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Lee H, Lee J, Wu H, Kim J, Kim Y, Lee J, Eom K. PO-1079 An optimal assessment schedule in the head and neck cancer using parametric modeling. Radiother Oncol 2022. [DOI: 10.1016/s0167-8140(22)03043-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Park J, Wu H, Kim J, Lee J, Ahn S, Chung E, Eom K, Jeong W, Kwon T, Kim S, Wee C. PD-0823 Adjuvant Radiotherapy for Node-negative Parotid Gland Cancer Patients Undergoing Curative Resection. Radiother Oncol 2022. [DOI: 10.1016/s0167-8140(22)02964-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Eom K, Lee HR, Hyun JH, An H, Lee YS, Ho WK, Lee SH. Gradual decorrelation of CA3 ensembles associated with contextual discrimination learning is impaired by Kv1.2 insufficiency. Hippocampus 2021; 32:193-216. [PMID: 34964210 DOI: 10.1002/hipo.23400] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 11/30/2021] [Accepted: 12/12/2021] [Indexed: 12/13/2022]
Abstract
The associative network of hippocampal CA3 is thought to contribute to rapid formation of contextual memory from one-trial learning, but the network mechanisms underlying decorrelation of neuronal ensembles in CA3 is largely unknown. Kv1.2 expressions in rodent CA3 pyramidal cells (CA3-PCs) are polarized to distal apical dendrites, and its downregulation specifically enhances dendritic responses to perforant pathway (PP) synaptic inputs. We found that haploinsufficiency of Kv1.2 (Kcna2+/-) in CA3-PCs, but not Kv1.1 (Kcna1+/-), lowers the threshold for long-term potentiation (LTP) at PP-CA3 synapses, and that the Kcna2+/- mice are normal in discrimination of distinct contexts but impaired in discrimination of similar but slightly distinct contexts. We further examined the neuronal ensembles in CA3 and dentate gyrus (DG), which represent the two similar contexts using in situ hybridization of immediate early genes, Homer1a and Arc. The size and overlap of CA3 ensembles activated by the first visit to the similar contexts were not different between wild type and Kcna2+/- mice, but these ensemble parameters diverged over training days between genotypes, suggesting that abnormal plastic changes at PP-CA3 synapses of Kcna2+/- mice is responsible for the impaired pattern separation. Unlike CA3, DG ensembles were not different between two genotype mice. The DG ensembles were already separated on the first day, and their overlap did not further evolve. Eventually, the Kcna2+/- mice exhibited larger CA3 ensemble size and overlap upon retrieval of two contexts, compared to wild type or Kcna1+/- mice. These results suggest that sparse LTP at PP-CA3 synapse probably supervised by mossy fiber inputs is essential for gradual decorrelation of CA3 ensembles.
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Affiliation(s)
- Kisang Eom
- Cell Physiology Laboratory, Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Hyoung Ro Lee
- Cell Physiology Laboratory, Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jung Ho Hyun
- Cell Physiology Laboratory, Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Hyunhoe An
- Cell Physiology Laboratory, Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea.,Department of Brain and Cognitive Science, Seoul National University College of Natural Sciences, Seoul, Republic of Korea
| | - Yong-Seok Lee
- Cell Physiology Laboratory, Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Won-Kyung Ho
- Cell Physiology Laboratory, Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea.,Department of Brain and Cognitive Science, Seoul National University College of Natural Sciences, Seoul, Republic of Korea
| | - Suk-Ho Lee
- Cell Physiology Laboratory, Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea.,Department of Brain and Cognitive Science, Seoul National University College of Natural Sciences, Seoul, Republic of Korea
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Lee T, Kim I, Kim J, Song C, Kim Y, Kim K, No J, Suh D, Chung J, Eom K. PO-1295 Stereotactic ablative body radiotherapy boost for cervical cancer when brachytherapy is not feasible. Radiother Oncol 2021. [DOI: 10.1016/s0167-8140(21)07746-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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KIM D, Wu H, Kim J, Ahn S, Chung E, Eom K, Jung Y, Jeong W, Kwon T, Kim S, Wee C. PO-0986 Radiotherapy versus Surgery in Early Stage HPV-positive Oropharyngeal Cancer. Radiother Oncol 2021. [DOI: 10.1016/s0167-8140(21)07437-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Jeon Y, Min G, Park S, Park S, Yoon J, Lee S, Cho B, Eom K, Kim Y, Min C, Lee J, Cho S. Efficacy of ex vivo purging with CD34 positive selection during autologous stem cell transplantation in peripheral T-cell lymphomas. Cytotherapy 2021. [DOI: 10.1016/s1465324921003807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Matchar D, Duncan P, Lien C, Ong M, Lee M, Sim R, Eom K. THE STEPS TO AVOID FALLS IN THE ELDERLY (SAFE) STUDY. Innov Aging 2017. [DOI: 10.1093/geroni/igx004.979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- D. Matchar
- Duke-NUS Graduate Medical School, Singapore, Singapore,
| | - P. Duncan
- Wake Forest School of Medicine, Winston Salem, North Carolina
| | - C.T. Lien
- Changi General Hospital, Singapore, Singapore,
| | - M.E. Ong
- Singapore General Hospital, Singapore, Singapore,
| | - M. Lee
- St Andrew’s Community Hospital, Singapore, Singapore,
| | - R. Sim
- Duke-NUS Graduate Medical School, Singapore, Singapore,
| | - K. Eom
- Duke-NUS Graduate Medical School, Singapore, Singapore,
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Chung J, Kang S, Suh T, Lee J, Kim J, Eom K. SU-F-T-625: Optimal Treatment Planning Strategy Among Arc Arrangements for Prostate SBRT with VMAT Technique. Med Phys 2016. [DOI: 10.1118/1.4956810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Kang S, Chung J, Eom K, Lee J, Suh T. SU-F-T-545: Dosimetric and Radiobiological Evaluation of Dose Calculation Algorithms On Prostate Stereotactic Body Radiotherapy Using Conventional Flattened and Flattening-Filter-Free Beam. Med Phys 2016. [DOI: 10.1118/1.4956730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Hyun JH, Eom K, Lee KH, Bae JY, Bae YC, Kim MH, Kim S, Ho WK, Lee SH. Kv1.2 mediates heterosynaptic modulation of direct cortical synaptic inputs in CA3 pyramidal cells. J Physiol 2015; 593:3617-43. [PMID: 26047212 DOI: 10.1113/jp270372] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Accepted: 05/26/2015] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS We investigated the cellular mechanisms underlying mossy fibre-induced heterosynaptic long-term potentiation of perforant path (PP) inputs to CA3 pyramidal cells. Here we show that this heterosynaptic potentiation is mediated by downregulation of Kv1.2 channels. The downregulation of Kv1.2 preferentially enhanced PP-evoked EPSPs which occur at distal apical dendrites. Such enhancement of PP-EPSPs required activation of dendritic Na(+) channels, and its threshold was lowered by downregulation of Kv1.2. Our results may provide new insights into the long-standing question of how mossy fibre inputs constrain the CA3 network to sparsely represent direct cortical inputs. ABSTRACT A short high frequency stimulation of mossy fibres (MFs) induces long-term potentiation (LTP) of direct cortical or perforant path (PP) synaptic inputs in hippocampal CA3 pyramidal cells (CA3-PCs). However, the cellular mechanism underlying this heterosynaptic modulation remains elusive. Previously, we reported that repetitive somatic firing at 10 Hz downregulates Kv1.2 in the CA3-PCs. Here, we show that MF inputs induce similar somatic firing and downregulation of Kv1.2 in the CA3-PCs. The effect of Kv1.2 downregulation was specific to PP synaptic inputs that arrive at distal apical dendrites. We found that the somatodendritic expression of Kv1.2 is polarized to distal apical dendrites. Compartmental simulations based on this finding suggested that passive normalization of synaptic inputs and polarized distributions of dendritic ionic channels may facilitate the activation of dendritic Na(+) channels preferentially at distal apical dendrites. Indeed, partial block of dendritic Na(+) channels using 10 nm tetrodotoxin brought back the enhanced PP-evoked excitatory postsynaptic potentials (PP-EPSPs) to the baseline level. These results indicate that activity-dependent downregulation of Kv1.2 in CA3-PCs mediates MF-induced heterosynaptic LTP of PP-EPSPs by facilitating activation of Na(+) channels at distal apical dendrites.
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Affiliation(s)
- Jung Ho Hyun
- Cell Physiology Laboratory, Department of Physiology and bioMembrane Plasticity Research Centre, Seoul National University College of Medicine and Neuroscience Research Institute, Seoul National University Medical Research Centre, 103 Daehak-ro, Jongno-gu, Seoul, 110-799, Republic of Korea
| | - Kisang Eom
- Cell Physiology Laboratory, Department of Physiology and bioMembrane Plasticity Research Centre, Seoul National University College of Medicine and Neuroscience Research Institute, Seoul National University Medical Research Centre, 103 Daehak-ro, Jongno-gu, Seoul, 110-799, Republic of Korea
| | - Kyu-Hee Lee
- Cell Physiology Laboratory, Department of Physiology and bioMembrane Plasticity Research Centre, Seoul National University College of Medicine and Neuroscience Research Institute, Seoul National University Medical Research Centre, 103 Daehak-ro, Jongno-gu, Seoul, 110-799, Republic of Korea
| | - Jin Young Bae
- Department of Oral Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, 700-412, Republic of Korea
| | - Yong Chul Bae
- Department of Oral Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, 700-412, Republic of Korea
| | - Myoung-Hwan Kim
- Cell Physiology Laboratory, Department of Physiology and bioMembrane Plasticity Research Centre, Seoul National University College of Medicine and Neuroscience Research Institute, Seoul National University Medical Research Centre, 103 Daehak-ro, Jongno-gu, Seoul, 110-799, Republic of Korea
| | - Sooyun Kim
- Cell Physiology Laboratory, Department of Physiology and bioMembrane Plasticity Research Centre, Seoul National University College of Medicine and Neuroscience Research Institute, Seoul National University Medical Research Centre, 103 Daehak-ro, Jongno-gu, Seoul, 110-799, Republic of Korea
| | - Won-Kyung Ho
- Cell Physiology Laboratory, Department of Physiology and bioMembrane Plasticity Research Centre, Seoul National University College of Medicine and Neuroscience Research Institute, Seoul National University Medical Research Centre, 103 Daehak-ro, Jongno-gu, Seoul, 110-799, Republic of Korea
| | - Suk-Ho Lee
- Cell Physiology Laboratory, Department of Physiology and bioMembrane Plasticity Research Centre, Seoul National University College of Medicine and Neuroscience Research Institute, Seoul National University Medical Research Centre, 103 Daehak-ro, Jongno-gu, Seoul, 110-799, Republic of Korea
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Hyun JH, Eom K, Lee KH, Ho WK, Lee SH. Activity-dependent downregulation of D-type K+ channel subunit Kv1.2 in rat hippocampal CA3 pyramidal neurons. J Physiol 2013; 591:5525-40. [PMID: 23981714 DOI: 10.1113/jphysiol.2013.259002] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The intrinsic excitability of neurons plays a critical role in the encoding of memory at Hebbian synapses and in the coupling of synaptic inputs to spike generation. It has not been studied whether somatic firing at a physiologically relevant frequency can induce intrinsic plasticity in hippocampal CA3 pyramidal cells (CA3-PCs). Here, we show that a conditioning train of 20 action potentials (APs) at 10 Hz causes a persistent reduction in the input conductance and an acceleration of the AP onset time in CA3-PCs, but not in CA1-PCs. Induction of such long-term potentiation of intrinsic excitability (LTP-IE) was accompanied by a reduction in the D-type K(+) current, and was abolished by the inhibition of endocytosis or protein tyrosine kinase (PTK). Consistently, the CA3-PCs from Kv1.2 knock-out mice displayed no LTP-IE with the same conditioning. Furthermore, the induction of LTP-IE depended on the back-propagating APs (bAPs) and intact distal apical dendrites. These results indicate that LTP-IE is mediated by the internalization of Kv1.2 channels from the distal regions of apical dendrites, which is triggered by bAP-induced dendritic Ca(2+) signalling and the consequent activation of PTK.
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Affiliation(s)
- Jung Ho Hyun
- S.-H. Lee: Department of Physiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 110-799, Republic of Korea.
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Lee S, Lee J, Lee A, Park N, Lee S, Song S, Seo A, Lee H, Kim JI, Eom K. Augmented reality intravenous injection simulator based 3D medical imaging for veterinary medicine. Vet J 2012; 196:197-202. [PMID: 23103217 DOI: 10.1016/j.tvjl.2012.09.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Revised: 07/08/2012] [Accepted: 09/19/2012] [Indexed: 10/27/2022]
Abstract
Augmented reality (AR) is a technology which enables users to see the real world, with virtual objects superimposed upon or composited with it. AR simulators have been developed and used in human medicine, but not in veterinary medicine. The aim of this study was to develop an AR intravenous (IV) injection simulator to train veterinary and pre-veterinary students to perform canine venipuncture. Computed tomographic (CT) images of a beagle dog were scanned using a 64-channel multidetector. The CT images were transformed into volumetric data sets using an image segmentation method and were converted into a stereolithography format for creating 3D models. An AR-based interface was developed for an AR simulator for IV injection. Veterinary and pre-veterinary student volunteers were randomly assigned to an AR-trained group or a control group trained using more traditional methods (n = 20/group; n = 8 pre-veterinary students and n = 12 veterinary students in each group) and their proficiency at IV injection technique in live dogs was assessed after training was completed. Students were also asked to complete a questionnaire which was administered after using the simulator. The group that was trained using an AR simulator were more proficient at IV injection technique using real dogs than the control group (P ≤ 0.01). The students agreed that they learned the IV injection technique through the AR simulator. Although the system used in this study needs to be modified before it can be adopted for veterinary educational use, AR simulation has been shown to be a very effective tool for training medical personnel. Using the technology reported here, veterinary AR simulators could be developed for future use in veterinary education.
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Affiliation(s)
- S Lee
- Department of Veterinary Radiology and Diagnostic Imaging, College of Veterinary Medicine, Konkuk University, Seoul 143-701, Republic of Korea
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Yoon G, Eom K, Na S. Simple micromechanical model of protein crystals for their mechanical characterizations. EPJ Web of Conferences 2010. [DOI: 10.1051/epjconf/20100605001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Song C, Park S, Eom K, Kim J, Kim S, Kim J, Kim I. Potential Prognostic Value of HSP90 and PI3KA Expression in Breast Cancers. Int J Radiat Oncol Biol Phys 2009. [DOI: 10.1016/j.ijrobp.2009.07.477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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20
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Kang H, Eom K, Kim I, Park C. The Efficiency of Radiotherapy in the Treatment of Newly Diagnosed Intracranial Oligodendroglioma: Prognostic Factors for Tumor Recurrence and Survival. Int J Radiat Oncol Biol Phys 2007. [DOI: 10.1016/j.ijrobp.2007.07.1263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Eom K, Kim I, Cho B, Jung H, Heo D, Shin H, Ahn H. 205. Int J Radiat Oncol Biol Phys 2006. [DOI: 10.1016/j.ijrobp.2006.07.237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Jang S, Lee J, Yoo J, Eom K, Kim D, Jeong H, Jung K. P-885 Accuracy and its affecting factors of prediction of functional reserves after lung cancer surgery. Lung Cancer 2005. [DOI: 10.1016/s0169-5002(05)81378-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Choi J, Lee H, Chang D, Lee K, Eom K, Lee Y, Choi M, Yoon J. Effect of dopamine on excretory urographic image quality and the prevention of contrast-induced nephropathy in dogs. J Vet Med Sci 2001; 63:383-8. [PMID: 11346171 DOI: 10.1292/jvms.63.383] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The effect of low dose dopamine on the excretory urographic image quality and contrast media-induced nephropathy in normal dogs (experiment 1) and the dogs with decreased renal function (experiment 2) were assessed. In experiment 2, decreased renal function was induced by gentamicin overdose. In each experiment, animals were divided into 3 groups. In group 1, only contrast medium (iohexol) was administered. In group 2, contrast medium plus intravenous fluid (0.9% saline) were administered. And in group 3, contrast medium plus intravenous fluid and low dose dopamine were administered. Investigated parameters included intrarenal resistive index (RI), serum BUN and creatinine concentrations, contrast medium elimination time and radiographic image quality. In experiment 1, RI of group I increased at 80 min after contrast medium administration (p<0.05), but RI of group 3 decreased at 48 and 72 hr (p<0.05). Serum BUN concentration of group 1 was higher than that of group 2 and 3 (p<0.05); in radiographic examination, contrast medium elimination time decreased in group 2 and 3, but image quality of group 2 was inferior to that of group 3. In experiment 2, image quality of group 3 only provided adequate visualization of renal structures. The formula of contrast medium plus low dose dopamine was found to provide good nephrogram and pyelogram image quality without supplemental contrast medium, and to protect renal tubules from prolonged exposure to concentrated contrast medium.
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Affiliation(s)
- J Choi
- College of Veterinary Medicine, Seoul National University, Republic of Korea
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Abstract
Canalography was performed to measure the diameter of the horizontal ear canal and to assess the clinical relevance of the measurements in identifying abnormalities of the ear canal. The diameter of the proximal and distal end of the annular cartilage in the horizontal ear canal was measured using canalography in 222 ears. The tympanic membrane could not be visualized with otoscopic examination in 70 ears even after ear cleansing. These canals were classified as being stenotic. The diameter of the proximal annular cartilage in the stenotic canals ranged from 0.8 to 3.1 mm (mean = 2.6 +/- 0.8 mm). The proximal annular cartilage was consistently smaller in diameter than the distal annular cartilage. The ratio between the diameter of the proximal and distal annular cartilage varied between dogs. In stenotic ear canals (70 ears) the ratio was less than 0.65. Total ear canal ablations and histopathological analysis were performed in 70 ear canals classified as stenotic after canalography. Hyperplasia of the epidermal layer was found in 56 stenotic canals. Stenosis of the canal due to otitis externa was found in the other 14 canals. Three canals with severe otitis externa were also diagnosed with canalography as having a ruptured tympanic membrane. The results suggest that canalography can be used to measure the diameter of the horizontal ear canal and to assess whether or not the tympanic membrane is ruptured prior to conservative or surgical therapy.
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Affiliation(s)
- K Eom
- Department of Veterinary Radiology, College of Veterinary Medicine, Seoul National University, Korea
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Abstract
Endoscopic ultrasonography was done in 12 normal adult dogs to investigate its efficacy in visualization of the pancreas. The endoscopic ultrasonographic device used in the present study had a curved-array ultrasound transducer mounted in front of the objective lens. The tip of the ultrasonic endoscope was inserted into the stomach, and all examinations of the pancreas were performed from within the stomach. Endoscopic ultrasonography provided good images of most parts of the pancreas except for the ends of each lobe. Useful information about the pancreatic parenchyma, including pancreatic lobular structure, pancreatic duct, and vessels of the pancreas was obtained by endoscopic ultrasonography. Blood flow within vessels was detected using color Doppler and pulsed-wave Doppler examination. These results suggest that endoscopic ultrasonography is available as an effective diagnostic modality in small animal practice.
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Affiliation(s)
- Y Morita
- Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
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Morita Y, Takiguchi M, Yasuda J, Eom K, Hashimoto A. Endoscopic ultrasonographic findings of the pancreas after pancreatic duct ligation in the dog. Vet Radiol Ultrasound 1998; 39:557-62. [PMID: 9845197 DOI: 10.1111/j.1740-8261.1998.tb01651.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Endoscopic ultrasonographic evaluation and gray-scale histogram analysis of pancreatic atrophy after pancreatic duct ligation were performed in four normal adult dogs. Using endoscopic ultrasonography, markedly dilated pancreatic ducts were visualized, and the pancreas became gradually atrophied with a hyperechoic parenchyma. In gray-scale histogram analysis of the pancreas, mean brightness increased gradually until 8 weeks, then decreased temporally. Standard deviation of the histogram increased markedly and then fluctuated until the 4th week, after which the mean brightness and standard deviation became stable. At 4 weeks postoperatively, collapse of most pancreatic acinar structures were observed, and each atrophic lobule was associated with a significantly large amount of interstitial fibrous tissue at histopathology. At 12 weeks postoperatively, most exocrine tissue had decreased and was partly replaced by fibrous and fatty tissue. These changes of mean brightness and standard deviation reflected the histologic analysis. These findings indicated that endoscopic ultrasonography is a useful technique to image such atrophic disorders of the pancreas as chronic pancreatitis. Furthermore, gray-scale histogram analysis provides helpful information for ultrasonographic tissue characterization of the pancreas.
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Affiliation(s)
- Y Morita
- Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Japan
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Jeon H, Eom K. Differential diagnosis between Taenia asiatica and T. Saginata adult tapeworms by enzyme-linked immunoelectrotransfer blot (EITB). Parasitol Int 1998. [DOI: 10.1016/s1383-5769(98)80605-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Abstract
1. The metabolism of pyrilamine, 2-[4-methoxybenzyl-(2-dimethylaminoethyl) amino] pyridine, was studied in adult male volunteers after a single oral dose of 50 mg. 2. Solvent extracts of urine obtained with or without enzyme hydrolysis were analysed by gc/ms after derivatization with MSTFA/TMSCI (N-methyl-N-trimethylsilyl-trifluoroacetamide/trimethyl chlorosilane). The structure of metabolites were determined based on EI mass spectra and confirmed with those of authentic standards. 3. Conjugated metabolites identified in the urine were pyrilamine, O-desmethylpyrilamine, and ring hydroxylated derivatives of pyrilamine. O-desmethylpyrilamine was also detected in low abundance as a free form. 4. These metabolites observed in human urine were quite different from those previously reported in rat.
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Affiliation(s)
- B C Chung
- Doping Control Center, Korea Institute of Science and Technology, Seoul
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