Publications by authors named "Yong-Gyu Kim"

Sensory abnormalities are observed in ~90% of individuals with autism spectrum disorders (ASD), but the underlying mechanisms are poorly understood. GluN2B, an NMDA receptor subunit that regulates long-term depression and circuit refinement during brain development, has been strongly implicated in ASD, but whether GRIN2B mutations lead to sensory abnormalities remains unclear. Here, we report that Grin2b-mutant mice show behavioral sensory hypersensitivity and brain hyperconnectivity associated with the anterior cingulate cortex (ACC).

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The vestibulo-ocular reflex (VOR) functions to maintain eye stability during head movement, and VOR gain can be dynamically increased or decreased by gain-up or gain-down adaptation. In this study, we investigated the impact of a differential training paradigm with varying frequencies and amplitudes on the level of VOR adaptation in mice. Training for gain-up (out of phase) or gain-down (in phase) VOR adaptation was applied for 60 min using two protocols: (1) oscillation of a drum and turntable with fixed frequency and differing amplitudes (0.

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Background: Although the occurrence of optokinetic reflex (OKR) adaptation after OKR training is well established, the dynamic properties of OKR adaptation has not been fully studied. This study aimed to examine the difference in the amount of OKR adaptation according to OKR training protocols which have different frequency or amplitude of drum oscillation.

Methods: Using C57BL/6N male mice, we induced OKR adaptation by 3 different categories of learning paradigm as follows: (1) Optokinetic drum oscillation for 60 min with same amplitude and different frequency.

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Although the superiority of spaced training over massed training has been established in many forms of learning, the learning efficacy between the two with respect to time efficiency may not be simply compared because a longer total duration of learning is required in spaced training than massed training due to spacing intervals intervening between training sessions in the former. The purpose of the present study was to evaluate the differences in the adaptation of the vestibulo-ocular reflex (VOR) and optokinetic reflex (OKR) after visuo-vestibular training, and to investigate the efficacy of spaced and massed training in mice. Associative visuo-vestibular stimulation was applied to induce VOR and OKR motor learning.

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To understand the information encoded in a connection between the neurons, postsynaptic current (PSC) has been widely measured as a primary index of synaptic strength in the field of neurophysiology. Although several automatic detection methods for PSCs have been proposed to simplify a workflow in the analysis, repetitive steps such as quantification and management of PSC data should be still performed with much effort. Here, we present Minhee Analysis Package, an integrated standalone software package that is capable of detecting, sorting, and quantifying PSC data.

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Histone modifications are a key mechanism underlying the epigenetic regulation of gene expression, which is critically involved in the consolidation of multiple forms of memory. However, the roles of histone modifications in cerebellum-dependent motor learning and memory are not well understood. To test whether changes in histone methylation are involved in cerebellar learning, we used heterozygous Kdm3b knockout (Kdm3b) mice, which show reduced lysine 9 on histone 3 (H3K9) demethylase activity.

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Emotional memory processing engages a large neuronal network of brain regions including the cerebellum. However, the molecular and cellular mechanisms of the cerebellar cortex modulating the fear memory network are unclear. Here, we illustrate that synaptic signaling in cerebellar Purkinje cells (PCs) STAT3 regulates long-term fear memory.

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Introduction: The superiority of spaced training, in which repeated training sessions are given with resting intervals, over massed training in learning efficacy has been well established. However, longer duration of total training time has been required for spaced training than massed training because spacing intervals intervene between training sessions in spaced training. Thus, the learning efficacy may not be simply compared between spaced and massed training in terms of "time efficiency.

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The optokinetic response (OKR), a reflexive eye movement evoked by a motion of the visual field, is known to adapt its strength to cope with an environmental change throughout life, which is a type of cerebellum-dependent learning. Previous studies suggested that OKR learning induces changes in in-vivo spiking activity and synaptic transmission of the cerebellar Purkinje cell (PC). Despite the recent emphasis on the importance of the intrinsic excitability related to learning and memory, the direct correlation between the intrinsic excitability of PCs and OKR learning has not been tested.

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Jangkanghwan (JKH) can delay weight loss in mice, promote weight gain during recovery, and reduce colonic shortening and colon weight. In addition, the murine disease activity index was controlled after treatment using JKH. It can reduce the content of pro-inflammatory factors in serum and expression in tissues, such as interleukin (IL)-6, IL-1β, tumor necrosis factor-α, interferon-γ, cyclooxygenase-2, and nuclear factor kappa-B; in contrast, the content and expression of IL-10 and the inhibitor of nuclear factor kappa-B kinase-α in the serum and tissues were increased.

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Climbing fibers (CFs) generate complex spikes (CS) and Ca transients in cerebellar Purkinje cells (PCs), serving as instructive signals. The so-called 'all-or-none' character of CSs has been questioned since the CF burst was described. Although recent studies have indicated a sensory-driven enhancement of PC Ca signals, how CF responds to sensory events and contributes to PC dendritic Ca and CS remains unexplored.

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Inflammation is a defense response of the body to stimuli. Curly dock (CD) is an herbal food with anti-inflammatory effects. Beopje is an herbal food processing method that reduces toxicity and enhances beneficial effects.

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The cerebellum improves motor performance by adjusting motor gain appropriately. As de novo protein synthesis is essential for the formation and retention of memories, we hypothesized that motor learning in the opposite direction would induce a distinct pattern of protein expression in the cerebellum. We conducted quantitative proteomic profiling to compare the level of protein expression in the cerebellum at 1 and 24 h after training from mice that underwent different paradigms of cerebellum-dependent oculomotor learning from specific directional changes in motor gain.

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The combined operation of optokinetic reflex (OKR) and vestibular-ocular reflex (VOR) is essential for image stability during self-motion. Retinal slip signals, which provide neural substrate for OKR and VOR plasticity, are delivered to the inferior olive. Although it has been assumed that the neural circuitry and mechanisms underlying OKR and VOR plasticity are shared, differential role of the inferior olive in the plasticity of OKR and VOR has not been clearly established.

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Mutations in RAS signaling pathway components cause diverse neurodevelopmental disorders, collectively called RASopathies. Previous studies have suggested that dysregulation in RAS-extracellular signal-regulated kinase (ERK) activation is restricted to distinct cell types in different RASopathies. Some cases of Noonan syndrome (NS) are associated with gain-of-function mutations in the phosphatase SHP2 (encoded by ); however, SHP2 is abundant in multiple cell types, so it is unclear which cell type(s) contribute to NS phenotypes.

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(Rc) and (Cm) mixture (Rc-Cm; AST2017-01) ameliorated production of proinflammatory cytokines, inflammation-related genes, and nitric oxide (NO) induced by lipopolysaccharide (LPS) in mouse splenocytes. Rc-Cm (6:4) and Taemyeongcheong (commercial healthy drink containing Rc-Cm) were co-administered along with LPS. Rc-Cm inhibited production of tumor necrosis factor α, interferon γ, interleukin (IL)-1β, and IL-6 in LPS-induced splenocytes.

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Control of Ca flux between the cytosol and intracellular Ca stores is essential for maintaining normal cellular function. It has been well established in both neuronal and non-neuronal cells that stromal interaction molecule 1 (STIM1) initiates and regulates refilling Ca into the ER. Here, we describe a novel, additional role for STIM1, the regulation of free cytosolic Ca, and the consequent control of spike firing in neurons.

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Long-term depression (LTD) at the parallel fiber (PF)-to-cerebellar Purkinje cell (PC) synapse is implicated in the output of PCs, the sole output of the cerebellar cortex. In addition to synaptic plasticity, intrinsic excitability is also one of the components that determines PC output. Although long-term potentiation of intrinsic excitability (LTP-IE) has been suggested, it has yet to be investigated how PF-PC LTD modifies intrinsic excitability of PCs.

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Accurate lateralization is important to improve treatment outcomes in horizontal semicircular canal (HSCC) benign paroxysmal positional vertigo (BPPV). To determine the involved side in HSCC-BPPV, the intensity of nystagmus has been compared in a head-roll test (HRT) and the direction of nystagmus was evaluated in a bow and lean test (BLT). The aim of this study is to compare the results of a BLT with those of a HRT for lateralization of HSCC-canalolithiasis and cupulopathy (heavy cupula and light cupula), and evaluate treatment outcomes in patients with HSCC-canalolithiasis.

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