Publications by authors named "Ja-Wook Koo"

Article Synopsis
  • Depression is a common disorder linked to imbalances in neurotransmitters like dopamine (DA), making DA restoration a key treatment focus.
  • Both medication and non-invasive techniques, such as transcutaneous auricular vagus nerve stimulation (taVNS), have shown potential in alleviating depressive symptoms, though taVNS's exact mechanism is still under investigation.
  • Experiments on mice revealed that taVNS reduces depressive-like behaviors by enhancing activity in the ventral tegmental area (VTA) and that inhibiting DA neurons in the VTA negated its effects, highlighting its role in depression treatment.
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Inhibitory neuronal circuits within the lateral septum (LS) play a key role in regulating mood and stress responses. Even though glial cells can modulate these circuits, the impact of astrocytes on LS neural circuits and their functional interactions remains largely unexplored. Here, we demonstrate that astrocytes exhibit increased intracellular Ca²⁺ levels in response to aversive sensory and social stimuli in both male and female mice.

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Social animals, including rodents, primates, and humans, partake in competition for finite resources, thereby establishing social hierarchies wherein an individual's social standing influences diverse behaviors. Understanding the neurobiological underpinnings of social dominance is imperative, given its ramifications for health, survival, and reproduction. Social dominance behavior comprises several facets, including social recognition, social decision-making, and actions, indicating the concerted involvement of multiple brain regions in orchestrating this behavior.

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  • The study explores how fear responses can resurface in new situations and the challenges this poses for therapies that aim to reduce fear.
  • Researchers investigated the role of specific brain regions (posterior parietal cortex and anterior cingulate cortex) using advanced techniques to understand the circuits involved in fear relapse.
  • Findings revealed that the pathway from the PPC to the ACC is crucial for this fear resurgence, with changes in neuron activity and the influence of parvalbumin-expressing interneurons affecting this process.
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  • The study focused on understanding the genotype-phenotype relationships in children with Gitelman syndrome (GS) by analyzing genetic variations in the SLC12A3 gene in 50 Korean children.
  • The median age for diagnosis was 10.5 years, with 68% having biallelic variants; those with truncating variants experienced more severe electrolyte imbalances compared to those without.
  • Findings suggest that children with monoallelic SLC12A3 variants exhibited similar clinical symptoms and treatment responses as those with biallelic variants.
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Stressful circumstances are significant contributors to mental illnesses such as major depressive disorder. Anhedonia, defined as loss of the ability to enjoy pleasure in pleasurable situations, including rewarding activities or social contexts, is considered a key symptom of depression. Although stress-induced depression is associated with anhedonia in humans and animals, the underlying molecular mechanisms of anhedonic responses remain poorly understood.

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Social animals compete for limited resources, resulting in a social hierarchy. Although different neuronal subpopulations in the medial prefrontal cortex (mPFC), which has been mechanistically implicated in social dominance behavior, encode distinct social competition behaviors, their identities and associated molecular underpinnings have not yet been identified. In this study, we found that mPFC neurons projecting to the nucleus accumbens (mPFC-NAc) encode social winning behavior, whereas mPFC neurons projecting to the ventral tegmental area (mPFC-VTA) encode social losing behavior.

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Mental health is influenced by the gut-brain axis; for example, gut dysbiosis has been observed in patients with major depressive disorder (MDD). Gut microbial changes by fecal microbiota transplantation or probiotics treatment reportedly modulates depressive symptoms. However, it remains unclear how gut dysbiosis contributes to mental dysfunction, and how correction of the gut microbiota alleviates neuropsychiatric disorders.

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The monoamine hypothesis has significantly improved our understanding of mood disorders and their treatment by linking monoaminergic abnormalities to the pathophysiology of mood disorders. Even 50 years after the monoamine hypothesis was established, some patients do not respond to treatments for depression, including selective serotonin reuptake drugs. Accumulating evidence shows that patients with treatment-resistant depression (TRD) have severe abnormalities in the neuroplasticity and neurotrophic factor pathways, indicating that different treatment approaches may be necessary.

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Article Synopsis
  • Researchers studied 172 people with kidney diseases using a special test called whole exome sequencing (WES) to find genetic problems.
  • They discovered that WES could diagnose genetic diseases in 63 of those patients, which is about 36.6%.
  • The testing was most helpful for younger patients (under 6 years old), and it even changed the way 10 of the patients were treated after finding their genetic issues.
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Social animals expend considerable energy to maintain social bonds throughout their life. Male and female mice show sexually dimorphic behaviors, yet the underlying neural mechanisms of sociability and their dysregulation during social disconnection remain unknown. Dopaminergic neurons in dorsal raphe nucleus (DRN) is known to contribute to a loneliness-like state and modulate sociability.

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Article Synopsis
  • This text serves as a correction for a previously published article, identified by its DOI: 10.3389/fpsyt.2021.685964.
  • The correction addresses specific errors or inaccuracies found in the original article to ensure the integrity of the research.
  • It emphasizes the importance of accurate reporting in academic publications to maintain credibility in the field of psychiatry.
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Background: Metabotropic glutamate receptor 5 (mGluR5) has been implicated in stress-related psychiatric disorders, particularly major depressive disorder. Although growing evidence supports the proresilient role of mGluR5 in corticolimbic circuitry in the depressive-like behaviors following chronic stress exposure, the underlying neural mechanisms, including circuits and molecules, remain unknown.

Methods: We measured the c-Fos expression and probability of neurotransmitter release in and from basolateral amygdala (BLA) neurons projecting to the medial prefrontal cortex (mPFC) and to the ventral hippocampus (vHPC) after chronic social defeat stress.

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The human brain is constantly active, even at rest. Alpha coherence is an electroencephalography (EEG) rhythm that regulates functional connectivity between different brain regions. However, the relationships between resting-state alpha coherence and N2/P3 components associated with response inhibition and cognitive processes have not been investigated in addictive disorders.

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We studied the brain mechanisms underlying action selection in a social dilemma setting in which individuals' effortful gains are unfairly distributed among group members. A stable "worker-parasite" relationship developed when three individually operant-conditioned rats were placed together in a Skinner box equipped with response lever and food dispenser on opposite sides. Specifically, one rat, the "worker," engaged in lever-pressing while the other two "parasitic" rats profited from the worker's effort by crowding the feeder in anticipation of food.

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The coronavirus disease 2019 (COVID-19) pandemic has disrupted our everyday life. Along with the fear of getting infected or of having loved ones infected, the lifestyle changes and the socioeconomic consequences of the pandemic have profound impact on mental health of the general population. While numerous studies on immediate psychological responses to COVID-19 are being published, there is a lack of discussion on its possible long-term sequelae.

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The COVID-19 (coronavirus disease 2019) pandemic has dramatically changed our daily lives and activities, including those originally intended to serve for leisure and pleasure. Drinking and online gaming became coping behaviors used to rescue ourselves from the stress and restricted lifestyle during the COVID-19 pandemic. However, frequent drinking and gaming can result in the pathological consequences of addiction.

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Although medial prefrontal cortex (mPFC) is known to play important roles in social behaviors, how early social experiences affect the mPFC and its subcortical circuit remains unclear. We report that mice singly housed (SH) for 8 weeks after weaning show a social recognition deficit, even after 4 weeks of resocialization. In SH mice, prefrontal infralimbic (IL) neurons projecting to the shell region of nucleus accumbens (NAcSh) show decreased excitability compared with group-housed (GH) mice.

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This study investigated attentional bias toward game-related cues in Internet gaming disorder (IGD) using electrophysiological markers of late positive potential (LPP) and identifying the sources of LPP. In addition, the association between LPP and decision-making ability was investigated. The IGD (n = 40) and healthy control (HC; n = 39) participants viewed a series of game-related and neutral pictures, while their event-related potentials (ERPs) were recorded.

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Behavioral sensitization, an animal model of drug addiction, persists for a prolonged period after repeated exposure to drugs of abuse. The persistence of an addiction behavioral phenotype suggests long-lasting changes in gene regulation at the epigenetic level. We measured the expression of histone deacetylases (HDACs) isoforms in the prefrontal cortex and dorsal striatum following the development of sensitization to cocaine (15 mg/kg, administered five times) and ethanol (0.

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Chronic stress causes physiological and hormonal adaptations that lead to neurobiological consequences and behavioral and cognitive impairments. In particular, chronic stress has been shown to drive reduced neurogenesis and altered synaptic plasticity in brain regions that regulate mood and motivation. The neurobiological and behavioral effects of stress resemble the pathophysiology and symptoms observed in psychiatric disorders, suggesting that there are similar underlying mechanisms.

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Often called the second brain, the gut communicates extensively with the brain and . The conversation between these two organs affects a variety of physiological mechanisms that are associated with our mental health. Over the past decade, a growing body of evidence has suggested that the gut microbiome builds a unique ecosystem inside the gastrointestinal tract to maintain the homeostasis and that compositional changes in the gut microbiome are highly correlated with several mental disorders.

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Aim: Although the incidence of urinary tract infection (UTI) in children with lower respiratory tract infection (LRTI) has been reported as 3.1-10.0%, the exact concomitant prevalence is questionable.

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Article Synopsis
  • Immunoglobulin A nephropathy (IgAN) is a prevalent kidney condition in children and adolescents, and this study analyzed its clinical features and outcomes over the past 30 years in a sample of 1,154 patients in Korea.
  • Of the patients studied, 5.6% progressed to severe chronic kidney disease (CKD), with a 10-year CKD-free survival rate of 91.2% and a 20-year rate of 75.6%, showing no significant differences based on diagnosis date.
  • The analysis indicated that symptoms like hematuria and proteinuria at diagnosis and lower renal function increased the risk of CKD progression, emphasizing the need for more proactive treatment in cases of pediatric IgAN. *
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