• The Journal of Korean Medicine
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• v.29 no.2
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• pp.21-31
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• 2008

Backgrounds: Singihwan is used "to strengthen inborn energy" and we suspected a protective effect on brain neuron cells. Objectives: The aim of this study was to evaluate the effects of Singihwan (SGH) on traumatic brain injury-induced delayed apoptosis in rat hippocampal dentate gyrus. Methods: For a surgical induction of traumatic brain injury (TBI), a 5 mm diameter stainless rod was used to make traumatic attack from the surface of the brain used by an impactor. The protective effect of the aqueous extract of SGH against TBI in the rat hippocampal dentate gyrus was investigated by using step-down avoidance task, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay, Bax immunohistochemistry, and 5-bromo-2'-deoxyuridine (BrdU) immunohistochemistry. Results: The aqueous extract of SGH suppressed the TBI-induced increase in apoptosis and cell proliferation in the hippocampal dentate gyrus. Conclusions: It is possible that the aqueous extract of SGH has a neuroprotective effect on TBI-induced neuronal cell death.

• Biomedical Science Letters
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• v.26 no.2
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• pp.57-65
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• 2020

Excessive drinking of alcohol is known to be one of the main causes of various neurological diseases, such as Alzheimer's disease. Scopoletin is known to have anti-inflammatory and antioxidative properties, and to protect nerve cells. This study examined whether scopoletin inhibits the alcohol-induced apoptosis of primary hippocampal neurons, and how scopoletin regulates several factors associated with the caspase-mediated pathway. To achieve this, the cell viability and apoptosis rate of primary hippocampal neurons were measured by Cell Counting Kit-8 and flow cytometry, respectively. Apoptosis-related protein expressions (Bax, Bid, caspase-3, caspase-9, and Poly (ADP-ribose) polymerase (PARP)) were analyzed by Western blotting, and the ANOVA method was used to confirm the significance of the measured results. As a result, scopoletin inhibited the expressions of alcohol-induced apoptosis and apoptosis-related proteins in primary hippocampal neurons. These results suggest that down-regulation of Bid, Bax, and cleaved caspase-9 expression induced by scopoletin down-regulates the expression of cleaved caspase-3, inhibits the expression of cleaved PARP, and finally, inhibits mitochondrial apoptotic pathways. The study suggests that scopoletin is worth developing as a candidate for neuroprotective agent.

• Journal of Life Science
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• v.9 no.2
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• pp.15-18
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• 1999

Tempting to further understand the molecular mechanism of pharmacological action of ethanol, we investigated the acute effects of ethanol on the GABA-activated current (IGABA) of the cultured Sprague-Dawley rat hippocampal neurons in primary culture using the whole-cell patch-clamp technique. Patch-clamp recordings revealed that ethanol potentiated the Cl- current in a concentration-dependent manner(1-300mM) in the majority of the cell studied. This study demonstrates that ethanol can potentiate IGABA in mammalian central neurons.

• Journal of Korean Medicine Rehabilitation
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• v.21 no.2
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• pp.15-30
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• 2011

Objectives : The present study investigated the effects of Achyranthis Radix on short-term memory, apoptotic neuronal cell death in the hippocampus following transient global ischemia in gerbils. Methods : The gerbils were divided into 5 groups(n=10); Sham operation group, ischemia-induced group, ischemia-induced and 50 mg/kg Achyranthis Radix-treated group, ischemia-induced and 100 mg/kg Achyranthis Radix-treated group, ischemia-induced and 200 mg/kg Achyranthis Radix-treated group. For this study, a step-down avoidance task, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling(TUNEL) assay, immunohistochemistry for caspase-3 and BrdU(5-Bromo-2'-deoxyuridine), and western blotting for bax, bcl-2 were performed. Results : The results revealed that ischemic injury impaired short-term memory and increased apoototic neuronal cell death in the hippocampal CA1(cornu ammonis area 1) region. Ischemic injury enhanced cell proliferation in the hippocampal CA1 region, the compensatory and adaptive process for excessive apoptosis. Achyranthis Radix treatment improved short-term memory by suppressing ischemia-induced apoptotic neuronal cell death in the hippocampal CA1 region. Also, Achyranthis Radix suppressed the ischemia-induced increase in cell proliferation in the hippocampal CA1 region. Conclusions : We showed that Achyranthis Radix alleviates ischemia-induced apoptotic neuronal cell death, thus facilitates the recovery of short-term memory impairment induced by ischemic cerebral injury.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.2
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• pp.447-450
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• 2003

To clerify the cytotoxicity of reactive oxygen species in cultured hippocampal neurons of neonatal mouse, toxic effect was measured by MTT assay after cultured cells were incubated for 3 hours in the media containing 1～40 μM concentrations of H₂O₂. In addition, the protective effect of vitamin E was determined in these cultrures. Cell viability was significantly decreased in a dose-dependent manner after exposure of 10 μM H₂O₂ to cultured mouse hippocampal neurons for 5 hours. In the protective effect of vitamin E, vitamin E prevented the H₂O₂-induced cytotoxicity in these cultures. From these results, it suggests that H₂O₂ has toxic effect in cultured mouse hippocampal neurons and vitamin E has protective effect on the cytotoxicity induced by H₂O₂.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.6
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• pp.423-429
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• 2012

Brain ischemia leads to overstimulation of N-methyl-D-aspartate (NMDA) receptors, referred as excitotoxicity, which mediates neuronal cell death. However, less attention has been paid to changes in synaptic activity and morphology that could have an important impact on cell function and survival following ischemic insult. In this study, we investigated the effects of reperfusion after oxygen/glucose deprivation (OGD) not only upon neuronal cell death, but also on ultrastructural and biochemical characteristics of postsynaptic density (PSD) protein, in the stratum lucidum of the CA3 area in organotypic hippocampal slice cultures. After OGD/reperfusion, neurons were found to be damaged; the organelles such as mitochondria, endoplasmic reticulum, dendrites, and synaptic terminals were swollen; and the PSD became thicker and irregular. Ethanolic phosphotungstic acid staining showed that the density of PSD was significantly decreased, and the thickness and length of the PSD were significantly increased in the OGD/reperfusion group compared to the control. The levels of PSD proteins, including PSD-95, NMDA receptor 1, NMDA receptor 2B, and calcium/calmodulin-dependent protein kinase II, were significantly decreased following OGD/reperfusion. These results suggest that OGD/reperfusion induces significant modifications to PSDs in the CA3 area of organotypic hippocampal slice cultures, both morphologically and biochemically, and this may contribute to neuronal cell death and synaptic dysfunction after OGD/reperfusion.

• Journal of Korean Medicine Rehabilitation
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• v.29 no.2
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• pp.91-99
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• 2019

Objectives The loss of maternal care during early postnatal period may increase development of mood-related disorders, such as depression, anxiety, and personality disorders. In this study, the effect of acupuncture on depression in relation with cell proliferation in the hippocampal gyrus dentatus was investigated using maternal-separated rat pups. Methods On the postnatal 14th day, rat pups from six dams were grouped into following groups: maternal care group, maternal separation group, maternal separation and non-acupoint-acupunctured group, maternal separation and Zusanli-acupunctured group, and maternal separation and fluoxetine-treated group. Acupuncture was performed from postnatal 28th day to postnatal 37th day. The rat pups that belong in the maternal separation and fluoxetine-treated group were injected subcutaneously with 5 mg/kg fluoxetine hydrochloride once a day for the same period of time. To evaluate activity of the rat pups, open field test was performed. Immunohistochemistry for serotonin (5-hydroxytryptamine, 5-HT) and tryptophan hydroxylase (TPH) in the dorsal raphe and for 5-bromo-2'-deoxyuridine (BrdU) in the hippocampal gyrus dentatus was conducted. Results The present results reveal that the activity was decreased by maternal separation. In contrast, acupuncture at Zusanli overcame maternal separation-induced hypoactivity. Maternal separation suppressed TPH expression and 5-HT synthesis in the dorsal raphe and decreased cell proliferation in the hippocampal gyrus dentatus of rat pups. In contrast, acupuncture at Zusanli alleviated maternal separation-induced decrease of 5-HT synthesisand TPH expression. Conclusions The present results demonstrate that acupuncture at Zusanli ameliorated depressive state through increasing cell proliferation and enhancing 5-HT synthesis.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2004.11a
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• pp.124-128
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• 2004

We have assessed amyloid ${\beta}-peptide$ $(A{\beta})-induced$ neurotoxicity in primary neurons and organotypic hippocampal slice cultures (OHC) in rat. Exposing cultured hippocampal and cerebellar granule neurons to $A{\beta}$ resulted in a decrease of MTT reduction, and in destruction of neuronal integrity. Treatment of these neurons with tunicamycin, an inhibitor of N-glycosylation in the endoplasmic reticulum (ER), also decreased MTT reduction in these neurons. S-allyl-L-cysteine (SAC), an active organosulfur compound in aged garlic extract, protected hippocampal but not cerebellar granule neurons against $A{\beta}$- or tunicamycin-induced toxicity. In the hippocampal neurons, protein expressions of casapse-12 and GRP 78 were significantly increased after $A{\beta}_{25-35}$ or tunicamycin treatment. The increase in the expression of caspase-12 was suppressed by simultaneously adding $1{\mu}M$ SAC in these neurons. In contrast, in the cerebellar granule neurons, the expression of caspase-12 was extremely lower than that in the hippocampal neurons, and an increase in the expression by $A{\beta}_{25-35}$ or tunicamycin was not detected. In OHC, ibotenic acid (IBO), a NMDA receptor agonist, induced concentration-dependent neuronal death. When $A{\beta}$ was combined with IBO, there was more intense cell death than with IBO alone. SAC protected neurons in the CA3 area and the dentate gyrus (DG) from the cell death induced by IBO in combination with $A{\beta}$, although there was no change in the CA1 area. Although protein expression of casapse-12 in the CA3 area and the DG was significantly increased after the simultaneous treatment of AI3 and IBO, no increase in the expression was observed in the CA1 area. These results suggest that SAC could protect against the neuronal cell death induced by the activation of caspase-12 in primary cultures and OHC. It is also suggested that multiple mechanisms may be involved in neuronal death induced by AI3 and AI3 in combination with IBO.

• Applied Microscopy
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• v.42 no.4
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• pp.200-206
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• 2012

Induction of neurogenesis can occur in the hippocampus in response to various pathological conditions, such as Alzheimer's disease. The aim of this study was to investigate the changes that occur in endogenous neural stem cells in response to amyloid beta $(A{\beta})_{25-35}$-induced neuronal cell damage in organotypic hippocampal slice cultures. Cresyl violet staining and Fluoro-Jade B staining were used to detect neuronal cell damage and changes of mossy fiber terminals were observed by Timm's staining. The immunofl uorescence staining was used to detect the newly generated cells in the subgranular zone (SGZ) of the dentate gyrus with specific marker, 5-bromo-2'-deoxyuridine (BrdU), Ki-67, Nestin, and doublecortin (DCX). In compared to control slices, neuronal cell damage was observed and the mossy fibers were expanded to CA3 area by treatment with $A{\beta}_{25-35}$. Ki-67/Nestin- and BrdU/DCX-positive cells were detected in the SGZ. In conclusion, these results demonstrate that $A{\beta}$-induced neuronal damage results in an increase in endogenous neural stem cells in rat hippocampal slice cultures not only for gliosis but also for neurogenesis.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.2
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• pp.177-181
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• 2015

The subfornical organ (SFO) is one of circumventricular organs characterized by the lack of a normal blood brain barrier. The SFO neurons are exposed to circulating glutamate ($60{\sim}100{\mu}M$), which may cause excitotoxicity in the central nervous system. However, it remains unclear how SFO neurons are protected from excitotoxicity caused by circulating glutamate. In this study, we compared the glutamate-induced whole cell currents in SFO neurons to those in hippocampal CA1 neurons using the patch clamp technique in brain slice. Glutamate ($100{\mu}M$) induced an inward current in both SFO and hippocampal CA1 neurons. The density of glutamate-induced current in SFO neurons was significantly smaller than that in hippocampal CA1 neurons (0.55 vs. 2.07 pA/pF, p<0.05). To further identify the subtype of the glutamate receptors involved, the whole cell currents induced by selective agonists were then compared. The current densities induced by AMPA (0.45 pA/pF) and kainate (0.83 pA/pF), non-NMDA glutamate receptor agonists in SFO neurons were also smaller than those in hippocampal CA1 neurons (2.44 pA/pF for AMPA, p<0.05; 2.34 pA/pF for kainate, p< 0.05). However, the current density by NMDA in SFO neurons was not significantly different from that of hippocampal CA1 neurons (1.58 vs. 1.47 pA/pF, p>0.05). These results demonstrate that glutamate-mediated action through non-NMDA glutamate receptors in SFO neurons is smaller than that of hippocampal CA1 neurons, suggesting a possible protection mechanism from excitotoxicity by circulating glutamate in SFO neurons.