• 동의신경정신과학회지
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• 제9궈1호
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• pp.1-24
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• 1998

The effects of Hyungbangjiwhangrang on the enhancement of learning and memory of AD model rats were studied with Morris water maze and radial arm maze. Sample group was electrolytically lesioned on nbM, and then daily treated with the medicine for two months. Control group with nbM lesion, and sham group with the sham operation were treated the vehicle for same duration. The following results were observed.1. As the learning trials of Morris water maze processed repeatedly, sham group achiened 201.64${\pm}$33.13 seconds in 1st trial, 153.14${\pm}$61.80 seconds in 2nd, 106.21${\pm}$46.81 seconds in 3rd, 76.64${\pm}$48.40 seconds in 4th, and 52.29${\pm}$38.25 seconds in 5th. The control group achieved 224.08${\pm}$29.16 in 1st trial, 191.77${\pm}$67.97 seconds in 2nd, 177.77${\pm}$65.44 seconds in 3rd, 140.92${\pm}$68.27 seconds in 4th, and 126.46${\pm}$79.15 seconds in 5th. The sample group achieved 223.36${\pm}$23.33 seconds in 1st trial, 215.86${\pm}$38.93 seconds in 2nd, 190.79${\pm}$51.57 seconds in 3rd, 155.79${\pm}$62.67 seconds in 4th, and 127.93${\pm}$62.11 seconds in 5th. Therefore, these data shows that all three groups were improved in learning capacity as trials were repeated, but the shame group showed prominent improvement in learning compared with the control group(p<0.05).2. In memory retention test of Morris water maze that counts the staying time in the target area, sham group stayed for 15.36${\pm}$5.39 seconds, the control group stayed for 5.54${\pm}$5.64 seconds, and the sample group stayed for 7.43${\pm}$6.09 seconds. The analysis of the memory retention data shows that the sham group marked more significant improvement stati- stically in memory retention compared with the control group(p<0.05).3. In the learning of radial arm maze, the number and rate of animals that arrive the learning criteria amounted 12 out of 14, 85.7% in sham group, 4 out of 13, 30.8% in the control group, and 10 out of 14, 71.4% in the sample group So, the sample group shows better learning capacity significantly compared with the control group(p<0.05). With the experimental results above, Hyungbangjiwhangtang can be supposed to have the improving effects on the learning and memory of AD rats induced by eletronical injury of nbM.

• 인지과학
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• 제10권4호
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• pp.41-50
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• 1999

해마가 공간기억에서 중요한 기능을 담당하는 해부학적 구조임은 잘 알려져 있는 사실이다. 최근에는 두정엽 후위도 공간기억에서 중요한 역할을 할 것임을 시사하는 연구 결과가 보고되었다. 지금가지의 연구결과로는 두정엽 후위가 공간학습의 작업기억에 중요한지, 참조기억에 중요한지는 확실치 않다. 본 연구는 이들 두 뇌 구조물이 공간학습에서 작업기억과 참조기억의 습득에 공헌하는지를 알아보기 위하여 방사미로를 통한 쥐의 학습에 각 뇌 구조물의 손상이 미치는 영향을 조사하였다. 여덟 개의 방사형 미로를 이용한 쥐를 공간학습에서 작업기억과 참조기억은 각각 8개의 미로 모두에 물이 존재할 때와 4개의 미로에만 물이 존재할 때, 쥐가 물이 존재하는 미로의 위치를 기억하여 찾는 능력을 측정하였다. 기억의 습득에서 해마나 두정엽 후위의 관련여부를 알아보기 위해서 이들 부위의 손상이 방사미로 학습에 미치는 영향을 조사하였다. 방사미로 학습에서 작업기억은 해마손상에 의하여 저하되었으며 두정엽 후위 손상에 의하여서는 영향을 받지 않았다. 한편 참조기억의 습득은 해마 손상뿐만 아니라 두정엽 후위 손상에 의해서도 저하되었다. 이상의 결과는 공간학습에서 작업기억에는 해마가, 참조기억의 습득과정에는 해마와 두정엽 후위가 모두 관여할 것임을 시사한다.

• 생물정신의학
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• 제4권2호
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• pp.237-245
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• 1997

The study was designed to evaluate the significant roles of SSRI in rat of depression model. Chronic exposure to mild unpredictable stress has been found to depress the consumption of sweet 1% sucrose solutions in the Sprague-Dawley rats. We applied the variety of 11 types of stress regimens and identified depressive behaviours(developed by Willner) in 70 Sprague-Dawley rats. Rats in experiments were stratified into 6 groups, ie ; 3 kinds of SSRI(paroxetine, fluoxetine, sertraline), clomipramine, choline and saline control. Memory function was evaluated by passive avoidance learning and retention test. The authors determined how long memory retention would remain improved with 24 hour, 1 week, 2 weeks, 3 weeks, and 4 weeks at training-testing interval in depressive states of the Sprague-Dawley rats. The results were as follows ; 1) There were no significant differences between the 6 groups at the 24 hour training-testing interval. 2) The paroxetine treated group showed significant differences from the control group at the 1 week and 2 weeks training-testing interval. 3) The paroxetine and the fluoxetine treated groups showed singificant differences from the control group at 3 week training-testing interval. 4) The paroxetine and the choline treated groups showed significant differences from the control group at 4 week training-testing interval. In summary, paroxetine had an effect on long term memory processing from 1st week to 4th week. Also, fluoxetine(at 3rd week) and choline(at 4th week) had effect on long term memory processing. Sertraline, clomipramine were ineffective on memory processing during 4 weeks observation. Possible explanations why paroxetine had early effect on memory processing than the other selective serotonin reuptake inhibitors are rapid bioavailability, which is the characteristics of pharmacokinetics of paroxetine. In clinical situation, author carefully suggest that SSRI would be beneficial to improve the memory function caused by depressive neurochemical changes.

• The Korean Journal of Physiology and Pharmacology
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• 제13권2호
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• pp.85-89
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• 2009

Puerariae flos (PF) is a traditional oriental medicinal plant and has clinically been prescribed for a long time. The purpose of the present study was to examine the effect of PF on repeated stress-induced alterations of learning and memory on a Morris water maze (MWM) test in ovariectomized (OVX) female rats. The changes in the reactivity of the cholinergic system were assessed by measuring the immunoreactive neurons of choline acetyltransferase (ChAT) in the hippocampus after behavioral testing. The female rats were randomly divided into four groups: the nonoperated and nonstressed group (normal), the sham-operated and stressed group (control), the ovariectomized and stressed group (OS), and the ovariectomized, stressed and PF treated group (OSF). Rats were exposed to immobilization stress (IMO) for 14 d (2 h/d), and PF (400 mg/kg, p.o.) was administered 30 min before IMO stress. Results showed that treatments with PF caused significant reversals of the stress-induced deficits in learning and memory on a spatial memory task, and also increased the ChA T immunoreactivities. In conclusion, administration of PF improved spatial learning and memory in OVX rats, and PF may be useful for the treatment of postmenopausal-related dementia.

• Biomolecules & Therapeutics
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• 제21권6호
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• pp.462-469
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• 2013

Eucommia ulmoides Oliv. Bark (EUE) is commonly used for the treatment of hypertension, rheumatoid arthritis, lumbago, and ischialgia as well as to promote longevity. In this study, we tested the effects of EUE aqueous extract in graded doses to protect and enhance cognition in scopolamine-induced learning and memory impairments in mice. EUE significantly improved the impairment of short-term or working memory induced by scopolamine in the Y-maze and significantly reversed learning and memory deficits in mice as measured by the passive avoidance and Morris water maze tests. One day after the last trial session of the Morris water maze test (probe trial session), EUE dramatically increased the latency time in the target quadrant in a dose-dependent manner. Furthermore, EUE significantly inhibited acetylcholinesterase (AChE) and thiobarbituric acid reactive substance (TBARS) activities in the hippocampus and frontal cortex in a dose-dependent manner. EUE also markedly increased brain-derived neurotrophic factor (BDNF) and phosphorylation of cAMP element binding protein (CREB) in the hippocampus of scopolamine-induced mice. Based on these findings, we suggest that EUE may be useful for the treatment of cognitive deficits, and that the beneficial effects of EUE are mediated, in part, by cholinergic signaling enhancement and/or protection.

• 대한한의학회지
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• 제21권2호
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• pp.25-36
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• 2000

Objectives : This study demonstrates the effects of Daejo-hwan on learning and memory impairment induced by L-NAME (75 mg/kg) treatment and on cerebral ischemic damage induced by middle cerebral artery (MCA) occlusion in rats. Methods : Daejo-hwan emulsion (73.3 mg/100 g/l ml) was administered to rats along a timed study schedule. The Moms water maze was used for learning and memory test of the rats. The MCA was occluded by using the intraluminal thread method. The brain slices were stained by 2 % triphenyl tetrazolium chloride (TTC) and 1 % cresyl violet solution. Infarct size, neuron cell number and size in penumbra was measured by using computer image analysis system. Results : 1. The escape latency of the Daejo-hwan treated group decreased significantly with respect to the control group. 2.The memory score of the Daejo-hwan treated group showed increase tendency, And the swimming distance was not different between the normal, the control, and the Daejo-hwan treated group. 3. The infarct size of the Daejo-hwan treated group decreased significantly with respect to the control group. 4. The total infarct volume of the Daejo-hwan treated group showed decrease tendency. And the brain edema index of the Daejo-hwan treated group decreased significantly with respect to the control group. 5. The neuron cell number and cell size in penumbra of the Daejo-hwan treated group increased significantly with respect to the control group. Conclusions : According to the above results, it is supposed that Daejo-hwan is clinically applicable to the vascular dementia.

• Biomolecules & Therapeutics
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• 제26권3호
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• pp.274-281
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• 2018

A previous study in humans demonstrated the sustained inhibitory effects of donepezil on acetylcholinesterase (AChE) activity; however, the effective concentration of donepezil in humans and animals is unclear. This study aimed to characterize the effective concentration of donepezil on AChE inhibition and impaired learning and memory in rodents. A pharmacokinetic study of donepezil showed a mean peak plasma concentration of donepezil after oral treatment (3 and 10 mg/kg) of approximately $1.2{\pm}0.4h$ and $1.4{\pm}0.5h$, respectively; absolute bioavailability was calculated as 3.6%. Further, AChE activity was inhibited by increasing plasma concentrations of donepezil, and a maximum inhibition of $31.5{\pm}5.7%$ was observed after donepezil treatment in hairless rats. Plasma AChE activity was negatively correlated with plasma donepezil concentration. The pharmacological effects of donepezil are dependent upon its concentration and AChE activity; therefore, we assessed the effects of donepezil on learning and memory using a Y-maze in mice. Donepezil treatment (3 mg/kg) significantly prevented the progression of scopolamine-induced memory impairment in mice. As the concentration of donepezil in the brain increased, the recovery of spontaneous alternations also improved; maximal improvement was observed at $46.5{\pm}3.5ng/g$ in the brain. In conclusion, our findings suggest that the AChE inhibitory activity and pharmacological effects of donepezil can be predicted by the concentration of donepezil. Further, $46.5{\pm}3.5ng/g$ donepezil is an efficacious target concentration in the brain for treating learning and memory impairment in rodents.

• 방송공학회논문지
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• 제27권6호
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• pp.897-905
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• 2022

비디오 영상 내 주요 프레임(Key Frame) 검출은 컴퓨터 비전 분야에서 꾸준히 연구되고 있는 분야 중 하나이다. 최근 심층학습(Deep Learning) 기술의 발전으로 비디오 영상에서의 주요 프레임 검출 성능이 향상 되었으나, 다양한 종류의 영상 콘텐츠 및 복잡한 배경으로 인해 여전히 효과적인 학습이 어려운 문제점이 있다. 본 논문에서는 대조적 학습(Contrastive Learning)과 메모리 뱅크(Memory Bank)를 통해 영상의 주요 프레임을 검출하는 새로운 방법을 제안한다. 제안하는 방법은 입력 프레임과 같은 영상 내 이웃하는 프레임 간 차이와 다른 영상 내 프레임과의 차이를 기반으로 특징 추출 신경망을 학습한다. 이와 같은 대조적 학습을 통해 메모리 뱅크에 주요 프레임을 저장 및 갱신하여 영상의 중복성을 효과적으로 제거한다. 비디오 영상 데이터셋에서의 실험 결과를 통해 제안하는 방법의 성능을 검증하였다.

• 대한한의학회지
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• 제28권2호통권70호
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• pp.1-12
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• 2007

Objective : Gagamchongmyung-tang is clinically one of the most popular prescriptions as an herbal medicine for the treatment of amnesia. In order to evaluate its neuroprotective effects on the ischemia-induced cognitive deficits caused by middle cerebral artery occlusion (MCAO), we examined its ability to reduce impairments of learning and memory of rats in the Morris water maze. Method and Result : Focal cerebral ischemia produced a decrease in acetylcholine transmission in the hippocampus, and deficits of learning and memory in the Morris water maze task. Treatment with two types of Gagamchongmyung-tang, methanol and water extracts, produced a substantial increase in acquisition in the Morris water maze. Treatment with methanol extract of Gagamchongmyung-tang increased the performance of the retention test in the Morris water maze. Consistent with behavioral data, immunohistochemical data showed that treatment with methanol extract, but not water extract, of Gagamchongmyung-tang significantly recovered reduction of AchE and ChAT reactivity in the hippocampal CAl area. Conclusion : These results demonstrated that methanol extract of Gagamchongmyung-tang has protective effects against ischemia-induced learning and memory impairments, and provided evidence of methanol extract of Gagamchongmyung-tang as a putative treatment for amnesia, vascular dementia, and longer memory.

• Biomolecules & Therapeutics
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• 제22권5호
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• pp.467-473
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• 2014

The purpose of this study is to investigate the memory enhancing effect and underlying molecular mechanism of arabinoxylan (AX), a major component of dietary fiber in wheat against scopolamine (SCO)-induced amnesia in Sprague-Dawley (SD) rats. Diverse behavior tests including Y-maze, Morris water maze, and passive avoidance tests were performed to measure cognitive functions. SCO significantly decreased the spontaneous alterations in Y-maze test and step-through latency in passive avoidance test, whereas increased time spent to find the hidden platform in Morris water maze test compared with the sham control group. In contrast, oral administration of AX (25 mg/kg and 50 mg/kg) effectively reversed the SCO-induced cognitive impairments in SD rats. Furthermore, AX treatment up-regulated the expression of brain-derived neurotrophic factor (BDNF) in the cortex and hippocampus via promoting activation of cAMP response element binding protein (CREB). Therefore, our findings suggest that AX can improve SCO-induced learning and memory impairment possibly through activation of CREB and up-regulation of BDNF levels, thereby exhibiting a cognition-enhancing potential.