• The Korean Journal of Physiology and Pharmacology
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• 제16권1호
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• pp.65-70
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• 2012

Synaptic long-term potentiation (LTP) and long-term depression (LTD) have been studied as mechanisms of ocular dominance plasticity in the rat visual cortex. Serotonin (5-hydroxytryptamine, 5-HT) inhibits the induction of LTP and LTD during the critical period of the rat visual cortex (postnatal 3~5 weeks). However, in adult rats, the increase in 5-HT level in the brain by the administration of the selective serotonin reuptake inhibitor (SSRI) fluoxetine reinstates ocular dominance plasticity and LTP in the visual cortex. Here, we investigated the effect of 5-HT on the induction of LTP in the visual cortex obtained from 3- to 10-week-old rats. Field potentials in layer 2/3, evoked by the stimulation of underlying layer 4, was potentiated by theta-burst stimulation (TBS) in 3- and 5-weekold rats, then declined to the baseline level with aging to 10 weeks. Whereas 5-HT inhibited the induction of LTP in 5-week-old rats, it reinstated the induction of N-methyl-D-aspartate receptor (NMDA)-dependent LTP in 8- and 10-week-old rats. Moreover, the selective SSRI citalopram reinstated LTP. The potentiating effect of 5-HT at 8 weeks of age was mediated by the activation of 5-$HT_2$ receptors, but not by the activation of either 5-$HT_{1A}$ or 5-$HT_3$ receptors. These results suggested that the effect of 5-HT on the induction of LTP switches from inhibitory in young rats to facilitatory in adult rats.

• 마이크로전자및패키징학회지
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• 제17권2호
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• pp.63-67
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• 2010

본 연구에서는 P3HT와 PCBM 물질을 전자도너와 억셉터 광활성층 물질로 사용하여 벌크이종접합 구조를 갖는 Glass/ITO/PEDOT:PSS/P3HT-PCBM/Al 구조의 유기박막태양전지를 제작하였다. P3HT와 PCBM은 각각 0.5 wt%의 농도로 톨루엔 용액에 용해하였다. 광활성층 농도를 최적화하기 위하여 P3HT:PCBM= 3:4, 4:4, 4:3 wt%의 농도비로 소자를 제작하고, 농도비에 따른 전기적 특성을 조사하였다. 또한 활성층의 후속열처리 온도가 소자의 전기적 특성에 미치는 영향을 조사하였다. P3HT와 PCBM의 농도비가 4:4 wt%의 비율에서 가장 우수한 전기적 특성을 나타내었으며, 이때 단락전류밀도 ($J_{SC}$), 개방전압 ($V_{OC}$), 및 충실인자 (FF)는 4.7 $mA/cm^2$, 0.48 V 및 43.1%를 각각 나타내었다. 또한 전력변환효율(PCE)은 0.97%의 값을 얻었다. 최적화된 농도비를 갖는 태양전지 소자에 대해 $150^{\circ}C$에서 5분, 10분, 15분, 20분간 후속 열처리를 실시한 결과 P3HT 전자도너의 흡광계수가 증가하는 경향을 보였다. 후속 열처리 조건이 $150^{\circ}C$에서 15분인 경우 전기적 특성이 열처리 하지 않은 소자에 비해 특성이 개선되었다. 즉, 이때의 전기적 특성은 $J_{SC},\;V_{OC}$, FF, PCE의 값이 각각 7.8 $mA/cm^2$, 0.55 V, 47%, 2.0%를 나타내었다.

• Bulletin of the Korean Chemical Society
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• 제30권11호
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• pp.2707-2712
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• 2009

5-$HT_{3}$ receptor;5-$HT_{3A}$ receptor channel activity;Novel 5-$HT_{3}$ receptor channel current blockers;Chlorophenyl substituted piperazinylethylaminomethylpyrazoles; The 5-$HT_{3A}$ receptors are one of ligand-gated ion channels and are known to be involved in visceral pain, anxiety, or anticancer agent-induced nausea and vomiting. In present study, we designed novel skeletons based on the developed 5-$HT_{3}$ receptor antagonists and evaluated their effects on 5-$HT_{3A}$ receptor channel currents ($I_{5-HT}$) of a series of pyrazole derivatives having N-chlorophenylpiperazine functionality (6-9). We found that most of N-p-chlorophenyl substituted piperazinyl-pyrazole derivatives (7b, 7c, 7e and 7h) exhibited the high potency for the inhibition of $I_{5-HT}$, whereas the compound without chloride (6) or with m-chlorophenyl group (a serious of 8 and 9) showed the low potency. These result indicate that p-chlorophenyl group is might play an important role for increasing the inhibitory potency on $I_{5-HT}$.

• The Korean Journal of Physiology and Pharmacology
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• 제6권6호
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• pp.293-297
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• 2002

The role of 5-hydroxytryptamine $(5-HT)_1A$ receptor activity in prenatal ischemia was studied, by injecting 8-hydroxy-dipropylaminotetraline (8-OH-DPAT; $50{\mu}g/kg,$ s.c.), a $5-HT_1A$ agonist on gestation day 17, and 30 min later inducing transient ischemia by ligating the uterine vessels for 30 min. On postnatal day 95, rats that had experienced prenatal ischemia showed impaired motor coordination and reduced concentration of 5-HT in the cerebellum compared with Sham-operated controls. In addition, they showed increased $5-HT_1A$ receptor densities in the cerebral cortex. Pretreatment with 8-OH-DPAT ameliorated the behavioral and neurochemical sequelae measured in the present study. The results suggest that $5-HT_1A$ receptors protect the brain from ischemic insult and/or facilitate recovery after prenatally experienced ischemia.

• Archives of Pharmacal Research
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• 제27권10호
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• pp.1065-1072
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• 2004

Depression is associated with a dysfunctional serotonin (5-hydroxytryptamine; 5-HT) system. More recently, several lines of evidence suggest that an important factor in the development of depression may be a deficit in the function and expression of $5-HT_{1A}$ receptors. The present study assessed if Nelumbinis Semen (N. s.) had an anti-depression effect through reversing a decrease in $5-HT_{1A}$receptor binding in rats with depression-like symptoms induced by chronic mild stress. Using a $5-HT_{1A}$ receptor binding assay, with a specific $5-HT_{1A}$receptor agonist, 8- OH-DPAT (8-hydroxy-2-(di-n-propylamino) tetralin), the mechanism of the anti-depression effect of N. s. on rats was investigated, and the effects compared with two well-known antidepressants, Hyperium Perforatum (St. Johns Wort) and fluoxetine (Prozac). Animals were divided into five groups: the normal (N) group without chronic mild stress (CMS), the control (C) group under CMS for 8 weeks, the Nelumbinis Semen (N. s.) treatment group under CMS for 8 weeks, the Hyperium Perforatum (H. p.) treatment group under CMS for 8 weeks and finally, the fluoxetine (F) treatment group under CMS for 8 weeks. Each treatment was administered to rats during the last 4 weeks of the 8-week CMS. A sucrose intake test was performed to test the anti-depression effect of N. s. The N. s. treatment significantly reversed the decreased sucrose intake under CMS (P<0.05 compared to control group under CMS). In the CA2 and CA3 regions of the hippocampus, both N. s. and H. p. reversed the CMS-induced decrease in $5-HT_{1A}$receptor binding. In the I to II regions of the frontal cortex, N. s. and H. p. also reversed the CMS-induced decrease in$5-HT_{1A}$receptor binding, and even showed a significant increase in $5-HT_{1A}$receptor binding compared to the F treatment group (N. s. vs. P, p<0.05, H. p. vs. P, p<0.05). However, in the hypothalamus, all treatments reversed the CMSinduced decrease in $5-HT_{1A}$receptor binding. This reversal effect of N. s. on the decrease in $5-HT_{1A}$receptor binding in the frontal cortex, hippocampus and hypothalamus of rat brains was very similar to that of H. p, but different from that of F. It is concluded that N. s. presents an anti-depression effect through enhancing $5-HT_{1A}$receptor binding.

• 대한약리학회지
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• 제28권2호
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• pp.137-146
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• 1992

신장기능조절에 있어서 중추 tryptamine계가 관련되어 있으며, $5-HT_1$수용체는 이뇨적인 역할을 하고 있는 반면에 $5-HT_2$ 및 $5-HT_3$수용체는 항이뇨적인 영향을 미치고 있음이 밝혀진 바 있다. 또한 $5-HT_1$수용체도 단일하지 않고 여러 subtype가 존재함이 알려져 있다. $5-HT_{1A}$수용체의 역할에 관해서는 신기능에 이뇨적인 영향을 미치고 있음이 시사된 바 있다. 본 연구에서는 중추 tryptamine성 신기능 조절에 있어서 $5-HT_{1B}$수용체의 역할을 구명하고자 하였다. 선택적 $5-HT_{1B}$ agonist인 TFMPP $8{\sim}750\;{\mu}g/kg$을 가토 측뇌실내로 투여하면 투여량에 비례하여 이뇨 및 Na과 K 배설의 증가를 초래하였으며, $250\;{\mu}g/kg$ 투여시에는 Na의 배설 분획이 5.44%까지 증가하였다. Na배설 촉진작용은 신혈류역학의 증가 보다도 훨씬 지속하여, 세뇨관에서의 Na재흡수 감소작용이 체액성 기전임을 시사하였다. TFMPP $250\;{\mu}g/kg$ icv투여시에 natriuresis와 함께 혈장내 atrial natriuretic peptide 농도가 약 6배 증가되었다. TFMPP $250\;{\mu}g/kg$을 정맥내로 투여하였을때는 뇌실내 투여시와는 상이하게 신기능에 별다른 유의한 변동을 초래하지 않았다. 이와같은 TFMPP의 diuresis 및 natriuresis는 각각 $5-HT_2$ 및 $5-HT_3$ 수용체의 선택적 antagonist인 ketanserin과 MDL 72222의 전처치에 의하여 차단되지 않았으며, methysergide에 의해서도 억제되지 않았다. 또한 $5-HT_{1A}$ antagonist로 알려진 NAN-190도 TFMPP의 작용을 차단하지 못하였으며 S(-)-propranolol도 영향을 미치지 않았다. 본 연구의 결과 중추 $5-HT_{1B}$수용체는 신장기능에 이뇨 및 Na배설 촉진적인 영향을 미치고 있고 이작용에 atrial natriuretic peptide가 관여함을 알 수 있었다.

• The Korean Journal of Physiology and Pharmacology
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• 제23권4호
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• pp.271-279
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• 2019

The lamina II, also called the substantia gelatinosa (SG), of the trigeminal subnucleus caudalis (Vc), is thought to play an essential role in the control of orofacial nociception. Glycine and serotonin (5-hydroxytryptamine, 5-HT) are the important neurotransmitters that have the individual parts on the modulation of nociceptive transmission. However, the electrophysiological effects of 5-HT on the glycine receptors on SG neurons of the Vc have not been well studied yet. For this reason, we applied the whole-cell patch clamp technique to explore the interaction of intracellular signal transduction between 5-HT and the glycine receptors on SG neurons of the Vc in mice. In nine of 13 neurons tested (69.2%), pretreatment with 5-HT potentiated glycine-induced current ($I_{Gly}$). Firstly, we examined with a $5-HT_1$ receptor agonist (8-OH-DPAT, $5-HT_{1/7}$ agonist, co-applied with SB-269970, $5-HT_7$ antagonist) and antagonist (WAY-100635), but $5-HT_1$ receptor agonist did not increase $I_{Gly}$ and in the presence of $5-HT_1$ antagonist, the potentiation of 5-HT on $I_{Gly}$ still happened. However, an agonist (${\alpha}$-methyl-5-HT) and antagonist (ketanserin) of the $5-HT_2$ receptor mimicked and inhibited the enhancing effect of 5-HT on $I_{Gly}$ in the SG neurons, respectively. We also verified the role of the $5-HT_7$ receptor by using a $5-HT_7$ antagonist (SB-269970) but it also did not block the enhancement of 5-HT on $I_{Gly}$. Our study demonstrated that 5-HT facilitated $I_{Gly}$ in the SG neurons of the Vc through the $5-HT_2$ receptor. The interaction between 5-HT and glycine appears to have a significant role in modulating the transmission of the nociceptive pathway.

• The Korean Journal of Physiology and Pharmacology
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• 제1권6호
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• pp.657-664
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• 1997

The effects of adenosine, adenosine A1 receptor antagonist (DPCPX), or NMDA receptor antagonist (APV) on the spontaneous release of $[^3H]-5-hydroxytryptamine$ ($[^3H]-5-HT$) during normoxic/normoglycemic or hypoxic/hypoglycemic period were studied in the rat hippocampal slices. The hippocampus was obtained from the rat brain and sliced $400\;{\mu}m$ thickness with the tissue slicer. After 30 min's preincubation in the normal buffer, the slices were incubated for 30 min in a buffer containing $[^3H]-5-HT$ ($0.1\;{\mu}M,\;74{\mu}Ci/8\;ml$) for uptake, and washed. To measure the release of $[^3H]-5-HT$ into the buffer, the incubation medium was drained off and refilled every ten minutes through sequence of 14 tubes. Induction of glucose/oxygen deprivation (GOD; medium depleting glucose and gassed with 95% $N_2/5%\;CO_2$) was done in 6th and 7th tube. The radioactivities in each buffer and the tissue were counted using liquid scintillation counter and the results were expressed as a percentage of the total radioactivities. When slices were exposed to GOD for 20 mins, the spontaneous release of $[^3H]-5-HT$ was markedly increased and this increase of $[^3H]-5-HT$ release was blocked by adenosine ($10\;{\mu}M$) or DL-2-amino-5-phosphonovaleric acid (APV; $30\;{\mu}M$). Adenosine $A_1$ receptor specific antagonist, 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) exacerbate GOD-induced increase of spontaneous release of $[^3H]-5-HT$. These results suggest that Adenosine may play a role in the GOD-induced spontaneous release of $[^3H]-5-HT$ through adenosine $A_1$ receptor activity.

• Journal of Trauma and Injury
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• 제19권1호
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• pp.14-20
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• 2006

Purpose: Although hypothermia has been used in many clinical situations, such as post cardiopulmonary resuscitation, stroke, traumatic brain injury, septic shock, and hemorrhagic shock, the mechanism by which it works has not been clearly elucidated. We aimed to evaluate the effect of hypothermia on the plasma nitric oxide (NO) concentration, lung iNOS expression, and histologic changes in intestinal ischemia-reperfusion (IR). Method: Male Sprague-Dawley rats were randomly divided into the hypothermia group (HT, n=8, $27{\sim}30^{\circ}C$) and the normothermia group (NT, n=8, $36{\sim}37^{\circ}C$). They underwent 30 min of intestinal ischemia by clamping the superior mesenteric artery, which was followed by 1.5 h of reperfusion. They were then sacrificed. The acute lung injury (ALI) score, the plasma NO concentration, and lung iNOS gene expression were measured. Results: Compared with the HT group, the NT group showed severe infiltrations of inflammatrory cells, alveolar hemorrhages, and interstitial hypertrophies in lung tissues. There were significant differences in the ALI scores between the NT and the HT groups ($8.7{\pm}1.5/HPF$ in NT vs $5.8{\pm}1.2/HPF$ in HT, p=0.008). Although the plasma NO concentration was slightly lower in the HT group, there was no significant difference between the two groups ($0.80{\pm}0.24{\mu}mol/L$ in NT vs $0.75{\pm}0.30{\mu}mol/L$ in HT, p=0.917). Lung iNOS gene expression was stronger in the NT group than in the HT group. The band density of the expression of iNOS in lung tissues was significantly increased in the NT group compared to the HT group ($5.54{\pm}2.75$ in NT vs$0.08{\pm}0.52$ in HT, p=0.002). Conclusions: This study showed that hypothermia in intestinal IR reduces inflammatory responses, ALI scores, and iNOS gene expression in lung tissues. There was no significant effect of hypothermia on the plasma NO concentration.

• 한방재활의학과학회지
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• 제18권4호
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• pp.73-83
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• 2008

Objectives : In this research, it was investigate that had effects on acupuncture techniques of $HT_{8}$(Shaofu) and $LR_{2}$(Xingjian) acupoints in high fat rats. We recorded data of weight gain, food intake, food efficiency, total cholesterol, triglyceride, AST, ALT, r-GTP, total bilirubin on rats fed high fat diet for 10 weeks. Methods : We divided experimental groups into four. Group of high-fat diet feeding and no treatment was control, group of high-fat diet feeding and acupuncture at $HT_{8}{\cdot}LR_{2}$ was Acu-1, group of high-fat diet feeding and acupuncture at $HT_{8}{\cdot}LR_{2}$ and rotated counter-clockwise 36times was Acu-2, high-fat diet feeding and acupuncture at $HT_{8}$(body direction)${\cdot}LR_{2}$(lower limb direction) and rotated counter-clockwise 36times was Acu-3. Results : In Acu-3 group, body weight on 2 weeks after starting acupuncture, food efficiency and the level of serum total cholesterol were decreased, and the level of HDL-cholesterol was increased. In Acu-1 group, the level of triglyceride was increased but ALT was decreased. Conclusions : These results suggest that treatment of acupuncture at $HT_{8}$(body direction)${\cdot}LR_{2}$(lower limb direction) and rotated counter-clockwise 36times may be having the influence on high fat by controlling the level of serum total cholesterol and HDL-cholesterol.