• Journal of Radiation Protection and Research
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• v.37 no.3
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• pp.123-128
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• 2012

Evidence suggests that even low-dose irradiation can lead to progressive cognitive decline and memory deficits, which implicates, in part, hippocampal dysfunction in both humans and experimental animals. This study examined whether diethyldithiocarbamate (DDC) could attenuate memory impairment, using passive avoidance and object recognition test, and suppression of hippocampal neurogenesis, using the TUNEL assay and immunohistochemical detection with markers of neurogenesis (Kiel 67 (Ki-67) and doublecortin (DCX)) in adult mice treated with gamma radiation (0.5 or 2 Gy). DDC was administered intraperitonially at a dosage of 1,000 $mg{\cdot}kg^{-1}$ of body weight at 30 min. before irradiation. In passive avoidance and object recognition memory test, the mice, trained for 1 day after acute irradiation (2 Gy) showed significant memory deficits compared with the sham controls. The number of TUNEL-positive apoptotic nuclei in the dentate gyrus (DG) was increased 12 h after irradiation. In addition, the number of Ki-67- and DCX-positive cells were significantly decreased. DDC treatment prior to irradiation attenuated the memory defect, and blocked the apoptotic death. DDC may attenuate memory defect in a relatively low-dose exposure of radiation in adult mice, possibly by inhibiting a detrimental effect of irradiation on hippocampal neurogenesis.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.14 no.2
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• pp.209-217
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• 2003

Object：This study examined the diagnostic validity of the K-ABC and the K-LDES for identifying the cognitive deficits and the learning difficulty of children with learning disorder and to diagnose the learning disorder. Method：The clinical group consisted of 15 children with learning disorder or attention deficit hyperactivity disorder accompanying learning problem(LP) and 14 children with attention deficit hyperactivity disorder. They were diagnosed either learning disorder or attention deficit hyperactivity disorder based on DSM-IV criteria by child psychiatrists and clinical psychologists visiting Seoul National University Children’s Hospital. The normal group was composed of 15 children be going to an elementary school. All groups were between the age of 7 and 12. The K-ABC was administered to the clinical and the normal group. The K-LDES was also administered to mothers of all groups. Result：There were no significant differences on sequential, simultaneous, mental processing subscales of the K-ABC in three groups. However, The LP group showed slightly lower scores on Achievement scale and significant low scores on Reading/Decoding than the other groups. On K-LDES, LP group showed significant low scores on Listing, Thinking, Reading, Writing, Spelling, Mathematical calculation, Learning quotient(LQ) than the other groups. Also there were significant correlations between K-ABC and K-LDES subscales. Conclusion：The result of present study showed that the K-ABC and the K-LDES are a valid and effective instruments for evaluating and diagnose the learning disorder.

• Journal of Life Science
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• v.19 no.3
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• pp.317-321
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• 2009

Down syndrome (DS) results from overexpressed genes on an extra copy of human chromosome 21. Among various phenotypes seen in DS patients, mental retardation, such as learning and memory deficits, is a major factor that prevents DS individuals from leading fully independent lives. The Dyrk1A gene that plays a critical role in neurodevelopment has been isolated from chromosome 21, and transgenic mice with over-expression of Dyrk1A show severe hippocampal dependent learning and memory defects. In the present study, as an initial step to test the treatment of Dyrk1A dependent mental retardation phenotypes in model animals, we isolated human Dyrk1A specific lentiviral short hairpin RNA (shRNA) that inhibits the exogenous human Dyrk1A expression, but not the endogenous mouse expression in transgenic mice with human Dyrk1A overexpression. This limited and specific repression of exogenous human Dyrk1A will prove to be valuable information, if Dyrk1A dependent learning and memory defects in DS patients could be treated or at least ameliorated in vivo.

• Biomolecules & Therapeutics
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• v.21 no.5
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• pp.405-410
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• 2013

Codonopsis lanceolata (Campanulaceae) traditionally have been used as a tonic and to treat patients with lung abscesses. Recently, it was proposed that the extract and some compounds isolated from C. lanceolata reversed scopolamine-induced memory and learning deficits. The purpose of this study was to evaluate the improvement of cognitive enhancing effect of C. lanceolata by steam and fermentation process in scopolamine-induced memory impairment mice models by passive avoidance test and Morris water maze test. The extract of C. lanceolata or the extract of steamed and fermented C. lanceolata (SFCE) was orally administered to male mice at the doses of 100 and 300 mg/kg body weight. As a result, mice treated with steamed and fermented C. lanceolata extract (SFCE) (300 mg/kg body weight, p.o.) showed shorter escape latencies than those with C. lanceolata extract or the scopolamine-administered group in Morris water maze test. Also, it exerted longer step-through latency time than scopolamine treated group in passive avoidance test. Furthermore, neuroprotective effect of SFCE on glutamate-induced cytotoxicity was assessed in HT22 cells. Only SFCE-treated cells showed significant protection at 500 ${\mu}g/ml$. Interestingly, steamed C. lanceolata with fermentation contained more phenolic acid including gallic acid and vanillic acid than original C. lanceolata. Collectively, these results suggest that steam and fermentation process of C. lanceolata increased cognitive enhancing activity related to the memory processes and neuroprotective effect than original C. lanceolata.

• Toxicological Research
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• v.31 no.4
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• pp.347-354
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• 2015

Excess manganese (Mn) is neurotoxic. Increased manganese stores in the brain are associated with a number of behavioral problems, including motor dysfunction, memory loss and psychiatric disorders. We previously showed that the transport and neurotoxicity of manganese after intranasal instillation of the metal are altered in Hfe-deficient mice, a mouse model of the iron overload disorder hereditary hemochromatosis (HH). However, it is not fully understood whether loss of Hfe function modifies Mn neurotoxicity after ingestion. To investigate the role of Hfe in oral Mn toxicity, we exposed Hfe-knockout ($Hfe^{-/-}$) and their control wild-type ($Hfe^{+/+}$) mice to $MnCl_2$ in drinking water (5 mg/mL) for 5 weeks. Motor coordination and spatial memory capacity were determined by the rotarod test and the Barnes maze test, respectively. Brain and liver metal levels were analyzed by inductively coupled plasma mass spectrometry. Compared with the water-drinking group, mice drinking Mn significantly increased Mn concentrations in the liver and brain of both genotypes. Mn exposure decreased iron levels in the liver, but not in the brain. Neither Mn nor Hfe deficiency altered tissue concentrations of copper or zinc. The rotarod test showed that Mn exposure decreased motor skills in $Hfe^{+/+}$ mice, but not in $Hfe^{-/-}$ mice (p = 0.023). In the Barns maze test, latency to find the target hole was not altered in Mn-exposed $Hfe^{+/+}$ compared with water-drinking $Hfe^{+/+}$ mice. However, Mn-exposed $Hfe^{-/-}$ mice spent more time to find the target hole than Mn-drinking $Hfe^{+/+}$ mice (p = 0.028). These data indicate that loss of Hfe function impairs spatial memory upon Mn exposure in drinking water. Our results suggest that individuals with hemochromatosis could be more vulnerable to memory deficits induced by Mn ingestion from our environment. The pathophysiological role of HFE in manganese neurotoxicity should be carefully examined in patients with HFE-associated hemochromatosis and other iron overload disorders.

• Korean Journal of Pharmacognosy
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• v.51 no.1
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• pp.70-77
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• 2020

Mentha arvensis is used traditional medicine to treat various disorders. In the present study, M. arvensis were extracted by the solid-phase microextraction (SPME) method and analyzed by gas chromatograph-mass spectrometry (GC-MS). We investigated the protective effects and mechanisms of a M. arvensis extract on scopolamine-induced cognitive and memory impairment. Mice were orally pretreated with a M. arvensis extract or normal saline, and then behavior tests were conducted 30 min after scopolamine injection. The antioxidant capacities were analyzed by free radical scavenging (DPPH and ABTS). Acetylcholinesterase (AChE) activity were also measured using Ellman's method ex vivo test. In behavior tests, percent of spontaneous alteration, escape latency and swimming time in target quadrant were improved by the administration of the M. arvensis extract, which suggests that the M. arvensis extract improves memory function in the scopolamine-treated mice model. In addition, M. arvensis extract showed inhibition of the free radical and AChE activity. The results of the present study suggest that the M. arvensis extract ameliorates scopolamine-induced cognitive and memory deficits through the inhibition of free radicals and AChE activity. Therefore, M. arvensis may be a promising neuroprotective agent for management of learning and memory improvements in human dementia patients.

• The Journal of Korean Physical Therapy
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• v.15 no.4
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• pp.199-207
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• 2003

This review describes the neurophathological mechanisms that are implicated in perinatal brain injury. Perinatal brain injury is the most important cause of morbidity and mortality to infants, often leading to spastic motor deficits, mental retardation, seizures, and learning impairments. The immature brain injury is usually caused by cerebral hypoxia-ischemia, hemorrhage, or infection. The important form of perinatal brain injury is the hypoxic-ischemic injury and the cerebral hemorrhage. The pathology of hypoxic-ischemic injury include delayed energy failure by mitochondrial dysfunction, neuronal excitotoxicity and vulnerability of white matter in developing brain. The immature brain has the fragile vascular bed of germinal matrix and can not effectively centralize their circulation. Therefore, the cerebral hemorrhage process is considered to be involved in the periventricular leukomalacia.

• Korean Journal of Medicinal Crop Science
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• v.22 no.1
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• pp.46-52
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• 2014

In traditional Korean and Chinese medicine, safflower (Carthamus tinctorius L.) for the treatment of central nervous system-related symptoms such as tremor, seizure, stroke and epilepsy. We investigated the effects of safflower could influence cerebral ischemia-induced neuronal and cognitive impairments. Administration of safflower for 1 day (200 mg/kg body weight, p.o.) increased the survival of hippocampal CA1 pyramidal neurons after transient global brain ischemia. And neurological functions measured as short term memory. Post-treatment with safflower for 2 times decreased the induction/reduction - induced production of neuronal cell loss from global cerebral ischemia. Safflower markedly decreased neuronal cell death and also caused a decrease in the content of thiobarbituric acid-reacting substances (TBARS) ($55.2{\pm}9.4{\mu}mol\;mg^{-1}$) and significant improvement of activities of glutathione (GSH) ($27.2{\pm}5.0{\mu}mol\;mg^{-1}$) in hippocampus. We conclude that treatment with safflower attenuated learning and memory deficits, and neuronal cell loss induced by global cerebral ischemia. These results suggest that safflower may be a potential candidate for the treatment of vascular dementia.

• Clinical and Experimental Pediatrics
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• v.55 no.10
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• pp.383-387
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• 2012

Purpose: Although benign rolandic epilepsy (BRE) is a benign condition, it may be associated with a spectrum of behavioral, psychiatric, and cognitive disorders. This study aimed to assess the cognitive and other neuropsychological profiles of children with BRE. Methods: In total, 23 children with BRE were consecutively recruited. All children underwent sleep electroencephalography (EEG) and were assessed on a battery of comprehensive neuropsychological tests including the Korean versions of the Wechsler intelligence scale for children III, frontal executive neuropsychological test, rey complex figure test, Wisconsin card sorting test, attention deficit diagnostic scale, and child behavior checklist scale. Results: The study subjects included 13 boys and 10 girls aged $9.0{\pm}1.6$ years. Our subjects showed an average monthly seizure frequency of $0.9{\pm}0.7$, and a majority of them had focal seizures (70%). The spike index (frequency/min) was $4.1{\pm}5.3$ (right) and $13.1{\pm}15.9$ (left). Of the 23 subjects, 9 showed frequent spikes (>10/min) on the EEG. The subjects had normal cognitive and frontal executive functions, memory, and other neuropsychological sub-domain scores, even though 8 children (35%) showed some evidence of learning difficulties, attention deficits, and aggressive behavior. Conclusion: Our data have limited predictive value; however, these data demonstrate that although BRE appears to be benign at the onset, children with BRE might develop cognitive, behavioral, and other psychiatric disorders during the active phase of epilepsy, and these problems may even outlast the BRE. Therefore, we recommend scrupulous follow-up for children with BRE.

• Journal of Ginseng Research
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• v.34 no.1
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• pp.51-58
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• 2010

This study compared the effects of black, white, and red ginseng extracts (WGE, RGE, BGE, 200 mg/kg, p.o.) on learning and memory deficits associated with scopolamine treatment (SCOP, 2 mg/kg, i.p.). Tacrine (THA, 10 mg/kg, p.o.) was used as a positive control. Ginseng significantly reversed SCOP-induced memory impairment in the passiveavoidance test and also reduced escape latency in training trials of the Morris water maze test. The increased acetylcholinesterase (AChE) activity produced by SCOP was significantly inhibited by WGE and RGE (p<0.001). SCOP administration had no effect on choline acetyltransferase (ChAT) activity, but RGE and BGE significantly increased ChAT activity (p<0.05). SCOP administration increased oxidative damage in the brain. Treatment of amnesic mice with ginseng extracts decreased malondialdehyde (MDA) levels and restored superoxide dismutase (SOD) and catalase (CAT) activity to control levels. These results suggest that black ginseng enhances cognitive activity by regulation of cholinergic enzymes and antioxidant systems.