The Development of Phasic and Tonic Inhibition in the Rat Visual Cortex

장현종,이덕주,조광현,박성원,김명준,윤신희,이덕주 대한약리학회 2010 The Korean Journal of Physiology & Pharmacology Vol.14 No.6

Gamma-aminobutyric acid (GABA)-ergic inhibition is important in the function of the visual cortex. In a previous study, we reported a developmental increase in GABAA receptor-mediated inhibition in the rat visual cortex from 3 to 5 weeks of age. Because this developmental increase is crucial to the regulation of the induction of long-term synaptic plasticity, in the present study we investigated in detail the postnatal development of phasic and tonic inhibition. The amplitude of phasic inhibition evoked by electrical stimulation increased during development from 3 to 8 weeks of age, and the peak time and decay kinetics of inhibitory postsynaptic potential (IPSP) and current (IPSC) slowed progressively. Since the membrane time constant decreased during this period, passive membrane properties might not be involved in the kinetic changes of IPSP and IPSC. Tonic inhibition, another mode of GABAA receptor-mediated inhibition, also increased developmentally and reached a plateau at 5 weeks of age. These results indicate that the time course of the postnatal development of GABAergic inhibition matched well that of the functional maturation of the visual cortex. Thus, the present study provides significant insight into the roles of inhibitory development in the functional maturation of the visual cortical circuits.

성인 ADHD 성향군의 회귀억제와 반응억제 결함

정진영,곽호완,장문선 한국심리학회 2008 한국심리학회지 일반 Vol.27 No.1

This study examined inhibition of return(IOR) and response inhibition deficits in adults with ADHD tendency using three web-based neuropsychological experiments. Specifically, using an IOR task in Exp. 1., we tested whether the amount of IOR in adults with ADHD would be decreased compared to control group. In Exp. 2 and 3, we also examined whether adults with ADHD tendency would show deficits in response inhibition compared to control group, using a continuous performance test(CPT) and a Stroop task. As results, 1) we found that ADHD tendency group showed less IOR compared to control group. 2) ADHD tendency group showed less response accuracy than control group. We then compared ADHD tendency group with controls performance in the CPT task. As a result, the ADHD tendency group showed more commission errors than the control group. Finally, the amount of stroop interference in Stroop task was not significant, while there was an interesting three-way interaction among the stroop, IOR and group conditions. These results suggest that ADHD tendency group had difficulties in efficient employment-deployment of attention, as shown in the IOR task. Moreover, the group difference in commission error obtained in CPT suggests that adults with ADHD tendency have deficits in response inhibition. Taken together, the result of the present study may be useful in understanding the characteristic of specific symptoms in adults with ADHD tendency. Further research is needed to generalize these results to clinically diagnosed patients with ADHD. 본 연구에서는 세 가지 웹-기반 실험과제를 이용하여 성인 ADHD 성향군의 회귀억제 결함과 반응억제 결함을 검토하고자 하였다. 구체적으로, 회귀억제과제를 실시한 후 통제군과 비교하여 성인 ADHD 성향군이 회귀억제력에서 결함이 있는지를 알아보고자 하였다. 그리고 연속수행과제와 스트룹과제를 실시한 후 통제군과 비교하여 ADHD 성향군이 반응 억제능력과 지속적 주의에서도 결함이 있는지를 알아보고자 하였다. 회귀억제과제에서 ADHD 성향군과 통제군의 반응시간을 비교한 결과, ADHD 성향군은 통제군에 비해 더 적은 회귀억제량을 보였으며, ADHD 성향군은 통제군에 비해 정반응률이 유의미하게 낮았다. 연속수행과제에서 ADHD 성향군과 통제군의 수행을 비교한 결과, ADHD 성향군이 통제군보다 오경보의 수가 더 많았으나 누락오류 수와 반응시간에서는 유의한 차이가 없었다. 마지막으로 스트룹과제 수행결과, 스트룹 간섭량과 정반응률에서 집단 간의 차이는 유의미하지 않았으나, 스트룹 간섭량 패턴에서 ADHD 성향군과 통제군의 패턴이 다르게 나타났다. 이러한 결과들을 종합하면, ADHD 성향군이 효율적인 주의억제와 반응억제를 실행하는데 어려움이 있고, 충동적이며 지속적인 주의를 유지하는 데 결함이 있는 것으로 생각된다. 본 연구의 결과들을 기초로, 성인 ADHD 성향군의 주의, 반응억제 등의 세부증상의 특성을 이해하는데 유용할 수 있고 이를 바탕으로 ADHD 성인을 진단하는 지표들을 마련하는 데 도움이 될 것으로 생각된다. 마지막으로, 향후 임상표본을 대상으로 본 연구 결과를 일반화시키기 위한 연구가 필요할 것으로 생각된다.

The Development of Phasic and Tonic Inhibition in the Rat Visual Cortex

Jang, Hyun-Jong,Cho, Kwang-Hyun,Park, Sung-Won,Kim, Myung-Jun,Yoon, Shin-Hee,Rhie, Duck-Joo The Korean Society of Pharmacology 2010 The Korean Journal of Physiology & Pharmacology Vol.14 No.6

Gamma-aminobutyric acid (GABA)-ergic inhibition is important in the function of the visual cortex. In a previous study, we reported a developmental increase in $GABA_A$ receptor-mediated inhibition in the rat visual cortex from 3 to 5 weeks of age. Because this developmental increase is crucial to the regulation of the induction of long-term synaptic plasticity, in the present study we investigated in detail the postnatal development of phasic and tonic inhibition. The amplitude of phasic inhibition evoked by electrical stimulation increased during development from 3 to 8 weeks of age, and the peak time and decay kinetics of inhibitory postsynaptic potential (IPSP) and current (IPSC) slowed progressively. Since the membrane time constant decreased during this period, passive membrane properties might not be involved in the kinetic changes of IPSP and IPSC. Tonic inhibition, another mode of $GABA_A$ receptor-mediated inhibition, also increased developmentally and reached a plateau at 5 weeks of age. These results indicate that the time course of the postnatal development of GABAergic inhibition matched well that of the functional maturation of the visual cortex. Thus, the present study provides significant insight into the roles of inhibitory development in the functional maturation of the visual cortical circuits.

Analysis of Free Ammonia Inhibition of Nitrite Oxidizing Bacteria Using a Dissolved Oxygen Respirometer

Dong Jin Kim,Dong Ig Lee,Gi Cheol Cha,Jurg Keller 대한환경공학회 2008 Environmental Engineering Research Vol.13 No.3

Free ammonia (NH₃-N) inhibition of nitrite-oxidizing bacteria (NOB) has been widely studied for partial nitrification (or nitrite accumulation) and denitrification via nitrite (NO₂-(-N)) as a low-cost treatment of ammonium containing wastewater. The literature on NH₃-N inhibition of NOB, however, shows disagreement about the threshold NH₃-N concentration and its degree of inhibition. In order to clarify the confusion, a simple and cheap respirometric method was devised to investigate the effect of free ammonia inhibition of NOB. Sludge samples from an autotrophic nitrifying reactor were exposed to various NH₃-N concentrations to measure the maximum specific nitrite oxidation rate (K(NO)) using a respirometer. NOB biomass was estimated from the yield values in the literature. Free ammonia inhibition of nitrite oxidizing bacteria was reversible and the specific nitrite oxidation rate (KNO) decreased from 0.141 to 0.116, 0.100, 0.097 and 0.081 mg NO₂-(-N)/mg NOB·h, respectively, as the NH₃-N concentration increased from 0.0 to 1.0, 4.1, 9.7 and 22.9 mg/L. A nonlinear regression based on the noncompetitive inhibition mode gave an estimate of the Inhibition concentration (K(I)) of free ammonia to be 21.3 mg NH₃-N/L. Previous studies gave (K(NO)) of Nitrobacter and Nitrospira as 0.120 and 0.032 mg/mg VSS·h. The free ammonia concentration which inhibits Nitrobacter was 30~50 mg NH₃-N/L and Nitrospira was inhibited at 0.04~0.08 mg NH₃-N/L. The results support the fact that Nitrobacter is the dominant NOB in the reactor. The variations in the reported values of free ammonia inhibition may be due to the different species of nitrite oxidizers present in the reactors. The respirometric method provides rapid and reliable analysis of the behavior and community of the nitrite oxidizing bacteria.

The Development of Phasic and Tonic Inhibition in the Rat Visual Cortex

Hyun-Jong Jang,Kwang-Hyun Cho,Sung-Won Park,Myung-Jun Kim,Shin Hee Yoon,Duck-Joo Rhie 대한생리학회-대한약리학회 2010 The Korean Journal of Physiology & Pharmacology Vol.14 No.6

Gamma-aminobutyric acid (GABA)-ergic inhibition is important in the function of the visual cortex. In a previous study, we reported a developmental increase in GABA_A receptor-mediated inhibition in the rat visual cortex from 3 to 5 weeks of age. Because this developmental increase is crucial to the regulation of the induction of long-term synaptic plasticity, in the present study we investigated in detail the postnatal development of phasic and tonic inhibition. The amplitude of phasic inhibition evoked by electrical stimulation increased during development from 3 to 8 weeks of age, and the peak time and decay kinetics of inhibitory postsynaptic potential (IPSP) and current (IPSC) slowed progressively. Since the membrane time constant decreased during this period, passive membrane properties might not be involved in the kinetic changes of IPSP and IPSC. Tonic inhibition, another mode of GABA_A receptor-mediated inhibition, also increased developmentally and reached a plateau at 5 weeks of age. These results indicate that the time course of the postnatal development of GABAergic inhibition matched well that of the functional maturation of the visual cortex. Thus, the present study provides significant insight into the roles of inhibitory development in the functional maturation of the visual cortical circuits.

A crucial role of ROCK for alleviation of senescence-associated phenotype

Park, Joon Tae,Kang, Hyun Tae,Park, Chi Hyun,Lee, Young-Sam,Cho, Kyung A.,Park, Sang Chul Elsevier 2018 Experimental Gerontology Vol.106 No.-

<P><B>Abstract</B></P> <P>In our previous study, we uncovered a novel mechanism in which amelioration of Hutchinson-Gilford progeria syndrome (HGPS) phenotype is mediated by mitochondrial functional recovery upon <I>rho-associated protein kinase</I> (ROCK) inhibition. However, it remains elusive whether this mechanism is also applied to the amelioration of normal aging cells. In this study, we used Y-27632 and fasudil as effective ROCK inhibitors, and examined their role in senescence. We found that ROCK inhibition induced the functional recovery of the mitochondria as well as the metabolic reprogramming, which are two salient features that are altered in normal aging cells. Moreover, microarray analysis revealed that the up-regulated pathway upon ROCK inhibition is enriched for chromatin remodeling genes, which may play an important role in the alleviation of senescence-associated cell cycle arrest. Indeed, ROCK inhibition induced cellular proliferation, concomitant with the amelioration of senescent phenotype. Furthermore, the restorative effect by ROCK inhibition was observed <I>in vivo</I> as evidenced by the facilitated cutaneous wound healing. Taken together, our data indicate that ROCK inhibition might be utilized to ameliorate normal aging process and to treat age-related disease.</P> <P><B>Highlights</B></P> <P> <UL> <LI> ROCK inhibition induced the functional recovery of the mitochondria as well as the metabolic reprogramming </LI> <LI> The up-regulated pathways after ROCK inhibition were enriched for genes involved in chromatin remodeling. </LI> <LI> ROCK inhibition induced cellular proliferation, concomitant with the amelioration of senescent phenotype. </LI> </UL> </P>

불안과 감염병 대처와의 관계에서 위험지각 미디어 선택과 행동억제의 이중 매개효과

이보람,서경현 한국건강심리학회 2021 한국심리학회지 건강 Vol.26 No.1

This study identified the relationship between anxiety and the ability to cope with infectious diseases amongst 259 Korean adults over the age of 20, and examined the dual mediating effects of media selection in the risk perception and behavioral inhibition on the relationship. Anger was measured by trait anger, behavioral inhibition was measured by BIS (behavioral inhibition system), and the level of appropriate and inappropriate coping with infectious disease was also measured. The results of correlational analysis revealed that trait anger, media selection with risk perception, and behavioral inhibition were positively correlated with appropriate and inappropriate copings with infectious disease. There were positive relationships between trait anger, media selection with risk perception, and behavioral inhibition. In a mediating model of appropriate coping with infectious disease, the path trait anxiety mediated by media selection with risk perception, the path mediated by behavioral inhibition, and the path mediated by both variables were all significant. However, the direct path did not have significant effect. In a mediating model of inappropriate coping with infectious disease, the path trait anxiety mediated by media selection with risk perception, the path mediated by behavioral inhibition, and the path mediated by both variables were also significant. The total indirect effects were not significant, as the effect of media selection with risk perception was positive, and the effect of behavioral inhibition was negative in this model. This study provided useful findings about the role of trait anger, media selection with risk perception, and behavioral inhibition in Korean adults’ coping with infectious diseases. 본 연구에서는 성인의 불안과 감염병에 대한 대처 간의 관계를 확인하고, 그 관계를 위험지각 미디어 선택과 행동억제가 이중매개를 하는지를 검증하였다. 연구 참여자는 20세 이상의 성인 259명이었다. 본 연구에서는 불안을 특성불안으로, 행동억제는 행동억제체계로 측정하였으며, 적절한 감염병 대처는 물론 부적절한 감염병 대처도 측정하였다. 상관분석 결과, 특성불안, 위험지각 미디어 선택 및 행동억제가 전염병에 대한 적절한 대처뿐 아니라 부적절한 대처와도 정적 상관을 보였다. 특성불안, 위험지각 미디어 선택 및 행동억제 간에도 정적 상관이 있었다. 적절한 감염병 대처를 준거변인으로 한 이중 매개모형에서는 특성불안이 위험지각 미디어 선택을 매개로 한 경로, 행동억제를 매개로 한 경로, 이중매개 경로 모두 유의하였다. 그리고 이 모형에서는 직접 경로는 유의하지 않았다. 부적절한 감염병 대처를 준거변인으로 한 이중 매개모형에서도 특성불안이 위험지각 미디어 선택을 매개로 한 경로, 행동억제를 매개로 한 경로, 이중매개 경로 모두 유의하였다. 이 모형에서 위험지각 미디어 선택의 영향은 정적으로, 행동억제는 부적으로 영향을 주고 있었기 때문에, 총 간접효과는 유의하지 않았다. 이런 결과는 한국인의 감염병 대처에 대한 불안, 미디어 선택 및 행동억제에 대한 역할에 관한 정보를 제공한다.

Inhibition of Aromatase and α-Amylase by Flavonoids and Proanthocyanidins from Sorghum bicolor Bran Extracts

James L. Hargrove,Phillip Greenspan,Diane K. Hartle,Christopher Dowd 한국식품영양과학회 2011 Journal of medicinal food Vol.14 No.7

We compared the ability of simple flavonoids and proanthocyanidins in Sorghum bicolor bran extracts to inhibit enzymes in vitro. In particular, aromatase is a target for breast cancer therapy, and inhibition of α-amylase can reduce the glycemic effect of dietary starches. Proanthocyanidin-rich sumac sorghum bran extract inhibited α-amylase at a lower concentration (50% inhibitory concentration [IC50]=1.4 μg/mL) than did proanthocyanidin-free black sorghum bran extract (IC50=11.4 μg/mL). Sumac sorghum bran extract inhibited aromatase activity more strongly than black sorghum bran extract (IC50=12.1 μg/mL vs. 18.8 μg/mL, respectively). Bovine serum albumin (BSA), which binds proanthocyanidins, reduced inhibition by sumac but not black sorghum bran extract. When separated on Sephadex LH-20, sumac sorghum proanthocyanidins inhibited both enzymes but showed reduced inhibition with BSA. Flavonoids from either cultivar had higher IC50 values than proanthocyanidins, and BSA had little effect on their inhibition. Proanthocyanidins and simple flavonoids in LH-20 fractions both inhibited aromatase with mixed kinetics and affected Km and Vmax. The results show that potential health benefits of sorghum bran may include actions of monomeric flavanoids as well as proanthocyanidins.

KRAS mutant lung cancer cells are differentially responsive to MEK inhibitor due to AKT or STAT3 activation: Implication for combinatorial approach

Yoon, Young-Kwang,Kim, Hwang-Phill,Han, Sae-Won,Oh, Do Youn,Im, Seock-Ah,Bang, Yung-Jue,Kim, Tae-You Wiley Subscription Services, Inc., A Wiley Company 2010 Molecular carcinogenesis Vol.49 No.4

<P>KRAS is frequently mutated in nonsmall cell lung cancer (NSCLC), resulting in the activation of the MAPK/ERK kinase (MEK)/ERK pathway. High-throughput mutation profile has shown that lung cancer frequently harbors comutation of cancer-related genes. Therefore, given that cancer cells have multiple genetic alterations, combinatorial therapeutic strategy is demanded for effective cancer therapy. To address this, we first characterized MEK dependence in four NSCLC cells. Two cells (H358, A549) carried KRAS mutation only, and the other two (H23, H157) harbored comutation of KRAS/PTEN. H358 cells with KRAS mutation only were sensitive to MEK inhibition. However, the other KRAS mutant A549 cells were resistant to MEK inhibition. Previously, we have shown that dual inhibition of EGFR and MEK signaling shows a synergistic effect on KRAS mutant gastric cancer cells by suppressing compensatory activation of AKT. Here we also observed that this combination was effective in KRAS mutant A549 cells. However, the combination was ineffective in H23 and 157 cells with comutation of KRAS/PTEN. Compared to KRAS mutant/PTEN wild-type cells, signal transducer and activator of transcription 3 (STAT3) was significantly activated following MEK inhibition in KRAS/PTEN comutant cells. Combined STAT3 inhibition by a JAK2 inhibitor or gene knockdown with MEK inhibition blocked STAT3 activation, synergistically suppressed cell growth, and induced apoptosis in comutant cells. Taken together, our study provides molecular insights that help explain the heterogeneous response to MEK inhibition in KRAS mutant lung cancers, and presents a rationale for the clinical investigation of combination of MEK and EGFR inhibitor or MEK and JAK2 inhibitor depending on PTEN status. © 2010 Wiley-Liss, Inc.</P>

대학생의 행동억제/활성화 체계에 따른 자존감의 차이에 관한 연구

민성혜,유영미 한국인간발달학회 2006 人間發達硏究 Vol.13 No.1

The purpose of this study is to explore the differences in the young adults' self-esteem according to the clusters of behavioral inhibition/ behavioral activation systems. Subjects were 198 university students, with 91 men and 107 women. The Korean BIS/BAS (Kim & Kim, 2001) was used to measure young adults' behavioral inhibition/behavioral activation system, and The Self-Esteem Questionnaire(Baik, 2000) was used to measure young adults' self-esteem.. Descriptive statistics, hierachical cluster analysis for the clustering behavioral inhibition/behavioral activation systems, ANOVA were performed. The results of this study were as follows. First, there found five clusters of young adults' BIS/BAS; Consisting of Positive Cluster(27.3%), Constrained Cluster(22.7%), Inhibited/Activated Cluster(20.2%), Inhibited Cluster(16.7%) and Drive Cluster(13.1%). Second, The self-esteem differences corresponded to the young adults' behavioral inhibition/behavioral activation system clusters. The Inhibited Cluster showed less self-esteem and Positive Cluster showed more self-esteem. Especially, the young adults who showed more inhibited systems, whether along with the activation systems, they showed less self-esteem. In conclusion, young adults' self-esteem was differed according to the individual characteristics of the behavioral inhibition/behavioral activation systems.