• Proceedings of the KOSOMBE Conference
• /
• v.1997 no.05
• /
• pp.116-118
• /
• 1997

In hippocampal morphology Abnormalities, including unilateral or bilateral volume loss, are known to occur in epilepsy, Alzheimer's disease, and in certain amnestic syndromes. To detect such abnormalities in hippocampal morphology, we present a method that combines region growing and dynamic contour model to detect hippocampus from MRI brain data. The segmentation process is performed two steps. First region growing with a seed point is performed in the region of hippocampus and the initial contour of dynamic contour model is obtained. Second, the initial contour is modified on the basis of criteria that integrate energy with contour smoothness and the image gradient along the contour. As a result, this method improves fairly sensitivity to the choice of the initial seed point, which is often seen by conventional contour model. The power and practicality of this method have been tested on two brain datasets. Thus, we have developed an effective algorithm to extract hippocampus from MRI brain data.

• Molecules and Cells
• /
• v.25 no.1
• /
• pp.124-130
• /
• 2008

Astrocyte ion channels participate in ionic homeostasis in the brain. Inward rectifying potassium channels (Kir channels) in astrocytes have been particularly implicated in $K^+$ homeostasis because of their high open probability at resting potential and their increased conductance at high concentrations of extracellular $K^+$. We examined the expression of the Kir2.1 subunit, one of the Kir channel subunits, in the mouse brain by immunohistochemistry. Kir2.1 channels were widely distributed throughout the brain, with high expression in the olfactory bulb and the cerebellum. Interestingly, they were abundantly expressed in astrocytes of the olfactory bulb, while astrocytes in other brain regions including the hippocampus did not show any detectable expression. However, Kir2.1 channel-expressing cells were dramatically increased in the hippocampus by kainic acid-induced seizure and the cells were glial fibrillary acidic protein (GFAP)-positive, which confirms that astrocytes in the hippocampus express Kir2.1 channels under pathological conditions. Our results imply that Kir2.1 channels in astrocyte may be involved in buffering $K^+$ against accumulated extracellular $K^+$ caused by neuronal hyperexcitability under phathophysiological conditions.

• Journal of Nutrition and Health
• /
• v.34 no.7
• /
• pp.754-761
• /
• 2001

Effects of dietary fatty acids and vitamin E on antioxidant vitamin status were studied in rat brain sections. Sources of dietary fat(10t%) were safflower oil(SO) poor in $\omega$3 fatty acid and mixed oil (MO) with computer-adjustd fatty acid ratios(AA/DHA=1.4, $\omega$6/$\omega$3=6.3, P/M/S=1.0/1.5/1, AA=2.%)with (ME) and without(MO) vitamin E(500mg/kg diet). Rats were fed the three kinds of diet from 3-4 wks prior to the conception. At the age of 3 & 9wks of the 2nd generation rat, antioxidant vitamins were measured in frontal cortex(FC), corpus striatum (CS), cerebellum(CB) and hippocampus(HP) using a multiwavelength, reverse phase gradient HPLC system. The levels of antioxidant vitamins converged to the similar value in all groups at 9 wks of age. Retinol, lycopene and cryptoxanthin levels of all experimental groups were found to be the highest in hippocampus at both 3 & 9wks of age. The levels of vitamin E appeared to be higher in the order of HP>CS-CB>FC in MO & ME. Beta-carotene and retinol showed the lowest level in hippocampus of vitamin E supplemented groups, even though vitamin E level tended to be higher in other sections. It seemed that vitamin E has an inhibitory action on the uptake of beta-carotene or acts as a preferred antioxidant to beta-carotene in certain section of the brain. By improving fatty acid balance (AA/DHA = 1.4, $\omega$6/$\omega$3=6.3, P/M/S=1.0/1.5/1, AA = 2%), the levels of vitamin E, retinol, lycopene & beta=carotene tended to be higher in MO than in SO, although crytoxanthin became lower at 3wks of age. In short, dietary fatty acids and vitamin E have different influence on antioxidant vitamin status in different rat brain sections. The higher levels of antioxidant vitamins in hippocampus should be pursued further in relation to behavioral development of rats.

• The Journal of the Korea Contents Association
• /
• v.9 no.2
• /
• pp.309-317
• /
• 2009

This study was to investigate the effects of restoring cognition function and neurotrophic factor in the hippocampus according to memory and learning training in rats affected by brain injury. Brain injury was induced in Sprague-Dawley rats(36 rats) through middle cerebral artery occlusion(MCAo). And then experiment groups were randomly divided into three groups; Group I: Brain injury induction(n=12), Group II: the application for treadmill training after brain injury induction(n=12), Group III: the application for memory and learning training after brain injury induction(n=12). Morris water maze acquisition test and retention test were performed to test cognitive function. And the histological examination was also observed through the immunohistochemistric response of BDNF(brain-derived neurotrophic factor) in the hippocampus. For Morris water maze acquisition test, there were significant interactions among the groups with the time(p<.001). The time to find the circular platform in Group III was more shortened than in Group I, II on the 9th, 10th, 11th and 12th day. For Morris water maze retention test, there were significant differences among the groups(p<.001). The time to dwell on quadrant circular platform in Group III on the 13th day was the longest compared with other groups. And as the result of observing the immunohistochemistric response of BDNF in the hippocampus CA1, the response of immunoreactive positive in Group III on the 7th day increased more than that of Group I, II. These results suggested that the memory and learning training in rats with brain injury has a more significant impact on restoring cognitive function via the changes of neurotropic factor expression and synaptic neuroplasticity.

• Korean Journal of Biological Psychiatry
• /
• v.10 no.1
• /
• pp.20-44
• /
• 2003

Schizophrenics suffer not only psychotic symptoms but also cognitive deficits such as an attentional difficulty, memory impairment, poor abstraction, etc. These cognitive abnormalities have been reported to be significantly related to the social and occupational outcome in schizophrenia. Thus, it is important to explore the cause and pathophysiology for the cognitive abnormalities in patients with schizophrenia. In this regard, hippocampus is one of the most promising brain areas to search for the clue because it is closely involved in memory related function. In fact, during the past several decades, there have been extensive studies supporting hippocampal abnormalities as a cause of schizophrenia in both clinical and preclinical field. In this review, basic anatomical knowledge about hippocampus and major findings of preclinical and clinical studies which investigated the correlation between schizophrenia and hippocampus were highlighted. The contents are 1) anatomical structure of hippocampus, 2) neuronal pathway and receptor distribution in hippocampus, 3) function of hippocampus, 4) hippocampal animal model for schizophrenia, 5) hippocampus-related studies on antipsychotic drugs, and 6) clinical studies in hippocampus in patients with schizophrenia.

• Korean Journal of Exercise Nutrition
• /
• v.13 no.1
• /
• pp.23-28
• /
• 2009

The expression of c-Fos and c-Jun represents neuronal activity and plays a crucial role in the shaping of the development of brain. During the late pregnancy, exercise is known to influence neuronal activity of offspring. In the present study, the effect of swimming during pregnancy on the expression of c-Fos and c-Jun in the CA1, CA2, CA3 regions, and the dentate gyrus of the hippocampus of rat offspring was investigated using immunohistochemistry. Pregnant rats in the swimming group were forced to swim for 10 min once a day from 15 days after pregnancy until delivery. The expression of c-Fos and c-Jun in the CA1, CA2, CA3 regions, and the dentate gyrus of the hippocampus of pups was significantly increased by maternal swimming during late pregnant period. The present results show that prenatal swimming may enhance the neuronal activity of pups and affect the neonatal brain development.

• Journal of Korean Neurosurgical Society
• /
• v.50 no.3
• /
• pp.173-178
• /
• 2011

Objective : The rat middle cerebral artery thread-occlusion model has been widely used to investigate the pathophysiological mechanisms of stroke and to develop therapeutic treatment. This study was conducted to analyze energy metabolism, apoptotic signal pathways, and genetic changes in the hippocampus of the ischemic rat brain. Methods : Focal transient cerebral ischemia was induced by obstructing the middle cerebral artery for two hours. After 24 hours, the induction of ischemia was confirmed by the measurement of infarct size using 2,3,5-triphenyltetrazolium chloride staining. A cDNA microarray assay was performed after isolating the hippocampus, and was used to examine changes in genetic expression patterns. Results : According to the cDNA microarray analysis, a total of 1,882 and 2,237 genes showed more than a 2-fold increase and more than a 2-fold decrease, respectively. When the genes were classified according to signal pathways, genes related with oxidative phosphorylation were found most frequently. There are several apoptotic genes that are known to be expressed during ischemic brain damage, including Akt2 and Tnfrsf1a. In this study, the expression of these genes was observed to increase by more than 2-fold. As energy metabolism related genes grew, ischemic brain damage was affected, and the expression of important genes related to apoptosis was increased/decreased.Conclusion : Our analysis revealed a significant change in the expression of energy metabolism related genes (Atp6v0d1, Atp5g2, etc.) in the hippocampus of the ischemic rat brain. Based on this data, we feel these genes have the potential to be target genes used for the development of therapeutic agents for ischemic stroke.

• Journal of Korea Multimedia Society
• /
• v.18 no.2
• /
• pp.120-127
• /
• 2015

Mild Cognitive Impairment(MCI) is a prior step to Alzheimer's Disease(AD). It is different from AD which is seriously affecting daily life. Particularly, the hippocampus could be charged a crucial function for forming memory. MCI has a high risk about progress to AD. Our investigated research for a relationship between hippocampus and AD has been studied. The measurement of hippocampus volumetric is one of the most commonly used method. The three dimensional reconstructed medical images could be passible to interpret and its examination in various aspects but the cost of brain research with the medical equipment is very high. In this study, 3D visualization was performed from a series of brain Magnetic Resonance Images(MRI) and we have designed and implemented a competitive software tool based on the open libraries of Visualization ToolKit(VTK). Consequently, our visualization software tool could be useful to various medical fields and specially prognosis and diagnosis for MCI patients.

• The Korean Journal of Pain
• /
• v.35 no.3
• /
• pp.261-270
• /
• 2022

Background: The rostral ventromedial medulla (RVM) is a critical region for the management of nociception. The RVM is also involved in learning and memory processes due to its relationship with the hippocampus. The purpose of the present study was to investigate the molecular mechanisms behind orexin-A signaling in the RVM and hippocampus's effects on capsaicin-induced pulpal nociception and cognitive impairments in rats. Methods: Capsaicin (100 g) was applied intradentally to male Wistar rats to induce inflammatory pulpal nociception. Orexin-A and an orexin-1 receptor antagonist (SB-334867) were then microinjected into the RVM. Immunoblotting and immunofluorescence staining were used to check the levels of cyclooxygenase-2 (COX-2) and brain-derived neurotrophic factor (BDNF) in the RVM and hippocampus. Results: Interdental capsaicin treatment resulted in nociceptive responses as well as a reduction in spatial learning and memory. Additionally, it resulted in decreased BDNF and increased COX-2 expression levels. Orexin-A administration (50 pmol/1 µL/rat) could reverse such molecular changes. SB-334867 microinjection (80 nM/1 µL/rat) suppressed orexin's effects. Conclusions: Orexin-A signaling in the RVM and hippocampus modulates capsaicin-induced pulpal nociception in male rats by increasing BDNF expression and decreasing COX-2 expression.

• Biomolecules & Therapeutics
• /
• v.2 no.1
• /
• pp.16-22
• /
• 1994

Using 2 to 4 day-old postnatal rats, primary brain cell cultures were made from various brain regions (substantia nigra, hippocampus, striatum, and nucleus accumbens). Whole-cell patch clamp technique was used for electrophysiological studies. Neurons cultured from substantia nigra were characterized more in detail to test whether these cultured neurons were appropriate for physiological studies. Immunocytochemical and electrophysiological properties of these cultured neurons agreed with those from other in vivo or in vitro studies suggesting that cultured neurons maintained normal cytological and physiological conditions. Modulation of ionic channels through dopamine receptors were studied from brain areas where dopamine plays important roles on brain functions. When neurons were clamped near resting membrane potential (-74mV), R(+), R(+)-SKF 38393, a specific D$_1$receptor agonist, activated cultured striatal neurons, and dopamine itself produced biphasic responses. Responses of cultured hippocampal neurons to dopamine agonists were kinds of mirror images to those from striatal neurons; D$_1$receptor agonists inhibited hippocampal neurons but quinpirole, a D$_2$receptor agonist, activated them. Neurons cultured from nucleus accumbens were inhibited by dopamine.