Dependence of Synchronized Bursting Activity on Medium Stirring and the Perfusion Rate in a Cultured Network of Neurons

Ryoun Heo,Hyun Kim,Kyoung J. Lee 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.68 No.9

A cultured network of neurons coupled with a multi-electrode-array (MEA) recording system has been a useful platform for investigating various issues in neuroscience and engineering. The neural activity supported by the system can be sensitive to environmental fluctuations, for example, in the medium’s nutrient composition, ph, and temperature, and to mechanical disturbances, yet this issue has not been the subject. Especially, a normal practice in maintaining neuronal cell cultures involves an intermittent sequence of medium exchanges, typically at a time interval of a few days, and one such sudden medium exchange is unavoidably accompanied by many unintended disturbances. Here, based on a quantitative time-series analysis of synchronized bursting events, we explicitly demonstrate that such a medium exchange can, indeed, bring a huge change in the existing neural activity. Subsequently, we develop a medium perfusion-stirring system and an ideal protocol that can be used in conjunction with a MEA recording system, providing long-term stability. Specifically, we systematically evaluate the effects of medium stirring and perfusion rates. Unexpectedly, even some vigorous mechanical agitations do not have any impacts on neural activity. On the other hand, too much replenishment (e.g., 1.8 ml/day for a 1.8-ml dish) of neurobasal medium results in an excitotoxicity.

The Effects of Carnitine and / or Gamma-Aminobutyric Acid (GABA) Supplementation on the Recovery of Chronic Ethanol Administered Rats

Ju-Ryoun Soh,Tokuo T. Yamamoto,Youn-Soo Cha 한국식품영양과학회 2003 Preventive Nutrition and Food Science Vol.8 No.2

To investigate the effects of the supplementation of carnitine and/or γ-aminobutric acid (GABA), Sprague-Dawley male rats were orally treated with either an AIN-76 diet (control), a control diet plus ethanol (CE, 4 g ethanol/kg bw), CE plus L-carnitine (CEC, 0.5 g/kg bw), CE plus GABA (CEG, 0.5 g/kg bw), or CE plus L-carnitine plus GABA (CECG, 0.25 g/kg bw each) for 6 weeks. Serum triglyceride levels were increased in the CE group and were decreased significantly in the CEC, CEG and CECG groups. HDL-cholesterol was increased and LDL-cholesterol was decreased in the CEG and CECG groups compared with the CE group. Serum GOT and GPT levels increased by the chronic ethanol administration were decreased in the CEC group. In addition, we have evaluated the mRNA levels of carnitine palmitoyltransferase-I in those groups. Supplementation of carnitine/GABA had some recovery effects on the liver CPT-I mRNA levels which decreased by chronic ethanol administration. These results may suggest that supplementations of either L-carnitine or GABA are effective on the recovery of chronic ethanol-related symptoms, but no combined effects were shown.

개성공단 개발사업의 성과와 함의

허련(Ryoun Heo) 대한지리학회 2011 대한지리학회지 Vol.46 No.4

개성공단은 북한에서 남한이 시행한 최초의 공단이다. 정치, 경제, 사회, 문화적으로 남한과 다른 환경속에서 개발사업자로서 공단개발구상과 후보지 선정, 토지 취득, 조성공사 시행, 기반시설 설치, 분양, 기업유치, 유지관리 등 일련의 사업프로세스를 추진하는 과정에서 겪은 실무적 경험과 개발사업 중심의 시사점을 공유함으로써 향후, 개성공단 2단계, 3단계 뿐만아니라, 제2의 개성공단과 같은 남북경협사업에 도움이 되고자 한다. The purpose of this study is addressing the process of developing industrial complex in North Korea, especially in Gaeseong. The Gaeseong Industrial Complex(GIC) is the first project which is completed in North Korea by South Korean company. LH, the main developer of the project successfully made the various procedures, master planning, land acquiring, developing, attracting investment, managing SOC, for making the industrial complex competitive using its own know-how and experiences in South Korea. The New development experience of LH in Gaeseong Industrial Complex case would indicate various implications to us for making another developing project in North Korea.

Urinary Angiotensinogen Excretion and Intrarenal Angiotensinogen Expression in Minimal Change Disease Patients

( Hye Ryoun Jang ),( Ajin Jo ),( Ji Hyeon Park ),( Jung Eun Lee ),( Woo Seong Huh ),( Dae Joong Kim ),( Ha Young Oh ),( Yoon Goo Kim ) 대한신장학회 2011 Kidney Research and Clinical Practice Vol.30 No.6

Purpose: Urinary angiotensinogen (AGT) has been reported as an important marker reflecting the activity of intrarenal renin-angiotensin system (RAS) in chronic glomerulonephritis patients. We investigated urinary AGT excretion and intrarenal AGT expression in patients with minimal change disease (MCD). Methods: In 20 patients with biopsy-proven MCD, urinary and plasma AGT was measured using a sandwich ELISA and intrarenal AGT expression was measured with immunohistochemistry. Urine samples from normal healthy volunteers and patients with biopsy-proven thin basement membrane disease (TBM) were used as control groups. Results: MCD patients showed a wide range of natural logarithm of the urinary AGT/creatinine [ln (urinary AGT/Cr)] and the ln (urinary AGT/Cr) was higher in MCD patients compared with normal controls and TBM controls (normal control vs. TBM vs. MCD, 1.2±0.25 vs. 0.9±0.34 vs. 3.2±0.40). Intrarenal AGT expression was diverse in MCD patients (intrarenal AGT, arbitrary unit, 27.39-78.52 in TBM, 0.00-145.80 in MCD). Ln (urinary AGT/Cr) did not show a direct correlation with intrarenal AGT expression, plasma AGT, or urinary protein/creatinine ratio. Conclusion: Urinary AGT excretion and intrarenal AGT expression are enhanced in some MCD patients, suggesting that intrarenal RAS is activated in these patients.

Genetic Transformation with Herbicide-resistant Gene Does not alter Cross Ability and Pollen Viability in Chile Pepper

Taek-Ryoun Kwon(권택륜),Tae-San Kim(김태산),Young-Hwan Park(박용환),Tae-Hun Ryu(류태훈),Hwa-Suk Song(송화숙),Jeong-Keun Choi(최정근) 한국원예학회 2003 한국원예학회 학술발표요지 Vol.2003 No.10

Dependence of synchronized bursting activity on medium stirring and the perfusion rate in a cultured network of neurons

Heo, Ryoun,Kim, Hyun,Lee, Kyoung J. 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol. No.

<P>A cultured network of neurons coupled with a multi-electrode-array (MEA) recording system has been a useful platform for investigating various issues in neuroscience and engineering. The neural activity supported by the system can be sensitive to environmental fluctuations, for example, in the medium's nutrient composition, ph, and temperature, and to mechanical disturbances, yet this issue has not been the subject. Especially, a normal practice in maintaining neuronal cell cultures involves an intermittent sequence of medium exchanges, typically at a time interval of a few days, and one such sudden medium exchange is unavoidably accompanied by many unintended disturbances. Here, based on a quantitative time-series analysis of synchronized bursting events, we explicitly demonstrate that such a medium exchange can, indeed, bring a huge change in the existing neural activity. Subsequently, we develop a medium perfusion-stirring system and an ideal protocol that can be used in conjunction with a MEA recording system, providing long-term stability. Specifically, we systematically evaluate the effects of medium stirring and perfusion rates. Unexpectedly, even some vigorous mechanical agitations do not have any impacts on neural activity. On the other hand, too much replenishment (e.g., 1.8 ml/day for a 1.8-ml dish) of neurobasal medium results in an excitotoxicity.</P>

『 도덕경 』 과 스테이스의 신비사상

정윤(Ryoun Chung) 한국종교사학회 1999 韓國宗敎史硏究 Vol.7 No.-

N/A N/A

Gamma - Aminobutyric Acid and/or Carnitine Supplementation Alters Lipid and Some Immune Related Nutrient Levels in Mice

Ju-Ryoun Soh,Youn-Soo Cha 한국식품영양과학회 2004 Preventive Nutrition and Food Science Vol.9 No.1

This study investigated the effects of carnitine and/or γ-aminobutyric acid (GABA) supplementation on lipid profiles and some immune related nutrient in mice. Balb/c male mice were orally treated with either an AIN-76 diet (Con), a control diet plus carnitine (CS, 0.5 g/kg bw), a control diet plus GABA (GS, 0.5 g/kg bw) or a control diet plus carnitine plus GABA (CGS, 0.25 g/kg bw, respectively) for 6 weeks. There were no significant differences in feed consumption, energy intake, body weight gain or feed efficiency ratio among the groups during the experimental period. However, abdominal fat deposits were smaller in CS, GS and CGS groups compared with the Con group. Serum and liver triglycerides also were lower in CS, GS and CGS and serum total cholesterol was significantly lower in the CGS group compared with the Con group. Serum LDL cholesterol was lower in the CGS group and liver HDL cholesterol was significantly higher in the CS group compared with Con group. In serum, stearic acid and selecholeic acid were lower, but arachidic acid was higher in the GS group. Liver stearic acid was higher but oleic acid lower in CGS group compared with Con group. In carnitine supplemented groups, serum and liver nonesterified carntine (NEC), acidsoluble acylcarnitine (ASAC), total carnitine (TCNE) concentrations were higher in only the CS group, not CGS group. Serum vitamin A and E concentrations were not different among the groups. These results may suggest that carnitine and/or GABA supplementation improves lipid profiles in mice, but did not affect the immune-related nutrients that we measured under the experimental conditions of this study.

Phenotyping of Plants for Drought and Salt Tolerance Using Infra-Red Thermography

( Taek Ryoun Kwon ),( Kyung Hwan Kim ),( Hae Jin Yoon ),( Seung Kon Lee ),( Beom Ki Kim ),( Zamin Shaheed Siddiqui ) 한국육종학회 2015 Plant Breeding and Biotechnology Vol.3 No.4

Drought and salinity are the major environmental constrains in global agricultural production. Plant breeding for the drought and salt tolerance needs a proper assessment procedure to overcome stress constrain. Fundamental understanding on the physiological nature of the plant tolerance provides valuable information for the genetically modified crop`s development. Drought or salt stress induces several common physiological responses in plants such as water relation and photosynthetic capacitiy. It is because both stresses lead cellular dehydration in the plants, particularly, during the early phase of stress imposition. Drought and salinity decrease CO2 availability for photosynthesis via stomatal limitation as well as elevate leaf temperature due to partially closed stomata. In this scenario, stomatal regulation and plant water status are important aspects in abiotic stress environment. These physiological responses have a function to stabilize the temperature inside plant/leaf. Therefore phenotyping through an infra-red thermography (heat sensitive sensor), could be a useful tool in the selection of a tolerant genotypes. Infra-red thermography is a part of the electromagnetic spectrum which emits a certain amount of radiation as a function of their temperatures. In general, the plants which have less water, would have higher temperature and display more infra-red radiations. In abiotic stresses such as drought and salinity, plant water status is affected and varied from the sensitive to tolerant level. Infra-red images of plants are often linked with some of the physiological attributes to the tolerance. This review covers the limits, advantages, linkages, comparison and other prospectives of using thermal imagaes in modern phenotyping techniques.

Correlation between CD44 Expression and Biologic Behavior in Salivary Gland Tumors

Hae-Ryoun Park,Bong-Soo Park 대한구강악안면병리학회 1999 대한구강악안면병리학회지 Vol.23 No.1