• The Korean Journal of Physiology and Pharmacology
• /
• v.16 no.1
• /
• pp.65-70
• /
• 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.

• Korean Journal of Soil Science and Fertilizer
• /
• v.47 no.4
• /
• pp.269-274
• /
• 2014

Series of field experiments were conducted to evaluate the long term effect of gypsum and crop residue on crop yield and soil health in rice-wheat crop rotation system in salt affected soil. A saline-sodic field having $EC_e$ (electrical conductivity of the saturation extract) 4.77 ($dSm^{-1}$); pH ($H_2O$) 8.96; SAR 43.78 ($mmol\;L^{-1}$) and gypsum requirement (G.R.) 2.86 (Mg $acre^{-1}$) was selected on Soil Salinity Research Institute Farm. Five treatments consisting of ($T_1$) control, ($T_2$) gypsum at 100% G.R., ($T_3$) gypsum at 25% G.R. + wheat straw at $3Mg\;ha^{-1}$, ($T_4$) gypsum at 25% G.R. + rice straw at $3Mg\;ha^{-1}$, ($T_5$) gypsum at 25% G.R.+ rice and wheat straw at $3Mg\;ha^{-1}$ were replicated four times under completely randomized block design. The data indicated that grain and straw yield of rice and wheat was significantly (P<0.05) increased by all the amendments used either single or in combination. $T_2$ (gypsum at 100% G.R.) significantly (P<0.05) increased grain and straw yield of rice and wheat crops followed by $T_3$ (gypsum at 25% G.R. + wheat straw at $3Mg\;ha^{-1}$) when compared with control. Soil properties were also improved by used amendments, pronounced decreased in $EC_e$, $pH_s$ and SAR were recorded in $T_2$ followed by $T_3$. The efficiency of the treatments could be arranged in following order gypsum at 100% G.R.> gypsum at 25% G.R. + wheat straw at $3Mg\;ha^{-1}$ > gypsum at 25% G.R. + rice and wheat straw at $3Mg\;ha^{-1}$ > gypsum at 25% G.R. + rice straw at $3Mg\;ha^{-1}$ > control.

• Proceedings of the Korean Society of Embryo Transfer Conference
• /
• 2003.10a
• /
• pp.65-65
• /
• 2003

• Korean Journal of Biological Psychiatry
• /
• v.13 no.4
• /
• pp.252-259
• /
• 2006

Sexual dysfunction is a relatively common adverse effect in the use of antidepressants. The sexual side effects may result in a lack of compliance with the prescribed antidepressants. The author reviewed the prevalence and updated treatment for the antidepressant-induced adverse effects focusing on sexual dysfunction. The incidence of sexual dysfunction is reported to exceed more than 50% especially with SSRIs. In order to obtain a quantified baseline and as an ongoing evaluation tool, clinicians may use some of the established questionnaires and validated instruments such as the Arizona Sexual Experience scale and Changes in Sexual Functioning Questionnaire. Clinicians should be aware that delayed ejaculation and orgasm, symptoms most frequently associated with antidepressants, are not usually associated with depression itself. Although many antidotes have been proposed, few have been subjected to double-blind trials. Some evidences have suggested that bupropion and buspiron may be the effective antidotes for SSRI induced sexual dysfunction. Additional trials will be requied to define what role, if any, bupropion and buspiron might have in the treatment of SSRI-induced sexual side effects. The available evidence is rather limited, with only small number of trials assessing each strategy. While further randomized data is awaited, for men with antidepressant induced erectile dysfunction, the addition of sidenafil or tadalafil may appear to be an effective strategy.

• Korean Journal of Biological Psychiatry
• /
• v.5 no.2
• /
• pp.162-165
• /
• 1998

The serotonin reuptake inhibitors(SRIs) and the serotonin selective reuptake inhibitors(SSRIs) are considered the first choice agents for pharmacologic treatment of obsessive-compulsive disordr(OCD). However, many patients with OCD experience little or no improvement in their symptoms when treated with SRIs or SSRIs. Patients who have experienced a partial or no response to an SRI/SSRI at 10 to 12 weeks are often considered for augmentation strategies. Nearly every class of psychotropic medications has been tried in an open fashion, though augmentation strategies have been somewhat disappointing.

• Journal of Marine Bioscience and Biotechnology
• /
• v.2 no.4
• /
• pp.201-208
• /
• 2007

Polychlorinated biphenyls (PCBs) are anthropogenic contaminants found globally in water, ice, soil, air and sediment. Modern analytical techniques allow us to determine these chemicals in environmental matrices at parts per trillion levels or lower. Environmental forensic on PCBs opens up new avenues of investigation such as transport and fate of water masses in oceans, sedimentation, onset of primary production, migration of marine mammals, their population distribution and pharmacokinetics of drugs inside organisms. By virtue of persistence, bioaccumulation, bioconcentration and structure-activity relationship PCBs emerge as unconventional chemical tracers of new sort.

• The Korean Journal of Physiology and Pharmacology
• /
• v.20 no.2
• /
• pp.193-200
• /
• 2016

Sertraline, a selective serotonin reuptake inhibitor (SSRI), has been reported to lead to cardiac toxicity even at therapeutic doses including sudden cardiac death and ventricular arrhythmia. And in a SSRI-independent manner, sertraline has been known to inhibit various voltage-dependent channels, which play an important role in regulation of cardiovascular system. In the present study, we investigated the action of sertraline on Kv1.5, which is one of cardiac ion channels. The effect of sertraline on the cloned neuronal rat Kv1.5 channels stably expressed in Chinese hamster ovary cells was investigated using the whole-cell patch-clamp technique. Sertraline reduced Kv1.5 whole-cell currents in a reversible concentration-dependent manner, with an $IC_{50}$ value and a Hill coefficient of $0.71{\mu}M$ and 1.29, respectively. Sertraline accelerated the decay rate of inactivation of Kv1.5 currents without modifying the kinetics of current activation. The inhibition increased steeply between -20 and 0 mV, which corresponded with the voltage range for channel opening. In the voltage range positive to +10 mV, inhibition displayed a weak voltage dependence, consistent with an electrical distance ${\delta}$ of 0.16. Sertraline slowed the deactivation time course, resulting in a tail crossover phenomenon when the tail currents, recorded in the presence and absence of sertraline, were superimposed. Inhibition of Kv1.5 by sertraline was use-dependent. The present results suggest that sertraline acts on Kv1.5 currents as an open-channel blocker.

• The Korean Journal of Physiology and Pharmacology
• /
• v.20 no.1
• /
• pp.75-82
• /
• 2016

Paroxetine, a selective serotonin reuptake inhibitor (SSRI), has been reported to have an effect on several ion channels including human ether-a-go-go-related gene in a SSRI-independent manner. These results suggest that paroxetine may cause side effects on cardiac system. In this study, we investigated the effect of paroxetine on Kv1.5, which is one of cardiac ion channels. The action of paroxetine on the cloned neuronal rat Kv1.5 channels stably expressed in Chinese hamster ovary cells was investigated using the whole-cell patch-clamp technique. Paroxetine reduced Kv1.5 whole-cell currents in a reversible concentration-dependent manner, with an $IC_{50}$ value and a Hill coefficient of $4.11{\mu}M$ and 0.98, respectively. Paroxetine accelerated the decay rate of inactivation of Kv1.5 currents without modifying the kinetics of current activation. The inhibition increased steeply between -30 and 0 mV, which corresponded with the voltage range for channel opening. In the voltage range positive to 0 mV, inhibition displayed a weak voltage dependence, consistent with an electrical distance ${\delta}$ of 0.32. The binding ($k_{+1}$) and unbinding ($k_{-1}$) rate constants for paroxetine-induced block of Kv1.5 were $4.9{\mu}M^{-1}s^{-1}$ and $16.1s^{-1}$, respectively. The theoretical $K_D$ value derived by $k_{-1}/k_{+1}$ yielded $3.3{\mu}M$. Paroxetine slowed the deactivation time course, resulting in a tail crossover phenomenon when the tail currents, recorded in the presence and absence of paroxetine, were superimposed. Inhibition of Kv1.5 by paroxetine was use-dependent. The present results suggest that paroxetine acts on Kv1.5 currents as an open-channel blocker.

• YAKHAK HOEJI
• /
• v.57 no.2
• /
• pp.101-109
• /
• 2013

Depressive disorders are the most common psychiatric problem in the elderly. Most depression treatment guidelines emphasize treatment with antidepressant medication and recommend that benzodiazepine use be minimized for limited period, particularly to elderly patients. In order to evaluate appropriate use of antidepressants and benzodiazepine, retrospective review of prescriptions was performed. The study population are older than 65 years who had been newly diagnosed with major depressive disorder in specialty mental health at a community general hospital from January $1^{st}$, 2007 to October $31^{th}$, 2012 (N=373). Initial antidepressant accounted for 89.5% with SSRI, and escitalopram accounted for 60.9% of SSRI group. 79% or more of the patients were prescribed the recommended dosage. The maintenance rate for 4 weeks of initial antidepressant was 48% and 6 weeks was 39%. Treatment-discontinuation rate was 68% at 3 month. Alprazolam (short acting benzodiazepine) was prescribed the most, followed by clonazepam (long acting benzodiazepine) and then diazepam. 55% of patients received a duplicated prescription for short acting plus long acting benzodiazepine. 61% of patients used long acting benzodiazepines. Prescribed dosages of benzodiazepines were commonly within a recommended range, while no one was prescribed a appropriate period (up to 2 weeks) except for the early discontinued patients. Appropriate use of zolpidem was only 16.2%. The depressed elderly treated in specialty mental health mostly received long-term treatment with benzodiazepines in combination with antidepressants, guideline recommendations was not followed. Multidisciplinary interventions like audit and feedback of benzodiazepine use are needed and education for the elderly is needed to properly maintain antidepressant treatment.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.15 no.2
• /
• pp.143-151
• /
• 2004

Objectives : Child and adolescent onset obsessive compulsive disorder(C-OCD) is known to be associated with poor drug response, high comorbid rate and strong genetic tendencies. Till now studies for C-OCD have been very rare in Korea. We conducted this study to investigate the informations about clinical features, familial psychiatric loading, treatment profiles and course of server C-OCD from the retrospective analysis of inpatient data of Seoul National University Children's Hospital. Method : Retrospective chart review and data analysis was performed. Twenty(male 16 : female 4) patients with final C-OCD diagnosis by DSM-IV at discharge from 1994 to 2002 were found and their medical chart, psychological data, family interview data and nursing reports were collected and analyzed. Results : 1) The sex ratio of C-OCD was male dominant(4:1). 2) Phenomenological, most common obsession was pathologic doubt, contamination fear, followed by aggressive obsession, need for symmetry, sexual obsession, most common compulsion was checking and washing, followed by breathing, movement, symmetry, repetitive asking, hoarding, mental compulsion. 3) Most common comorbid diagnosis was depression. Other axis-I diagnosis associated OCD were anxiety disorder, tic disorder, conduct and oppositional defiant disorder and psychosis. 4) Regarding psychiatric familial loadings, 17 patients(85%) had relatives with psychiatric disorders, OC-spectrum disorders(OCD or OCPD) were found in 9 patients(45%). 5) The majority of patients(75%) have received SSRI and antipsychotics treatment. The response rate above 'moderate improved" by CGI was 75%. 6) During follow-up period in outpatient clinic, five patients(25%) showed continuous complete remission, 10 patients (50%) did residual symptoms with chronic course. Conclusion : This seems to be the first systemic investigation of severe pediatric OCD patients in Korea. The children & adolescents with severe OCD in inpatient-setting showed the high comorbid rate, familial psychiatric loading, and combined pharmacotherapy with antipsychotics, As for symptoms, high rate of aggressive-sexual obsession and atypical compulsions like breathing and moving was reported in this study. Severe pediatric OCD patients, however, responded well to the combined SSRI and antipsychotics regimen.