• Title/Summary/Keyword: neuronal activity

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Zinc-induced Neurotoxicity and Its Role in Brain Diseases

  • Koh, Jae-Young
    • Proceedings of the Korean Biophysical Society Conference
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    • 1998.06a
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    • pp.14-14
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    • 1998
  • Mammalian brian contains substantial amounts of chelatable zinc in presynaptic vesicles of certain glutamatergic terminals. The synaptic zinc is released with intense neuronal activity, suggesting its role in synaptic transmission. However, in pathological conditions, zinc may get released too excessively, which may contribute to neuronal death as shown in cortical cultures.(omitted)

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Temporal Changes in Neuronal Activity of the Bilateral Medial Vestibular Nuclei Following Unilateral Labyrinthectomy in Rats

  • Park, Byung-Rim;Lee, Moon-Young;Kim, Min-Sun;Lee, Sung-Ho;Na, Han-Jo;Doh, Nam-Yong
    • The Korean Journal of Physiology and Pharmacology
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    • v.3 no.5
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    • pp.481-490
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    • 1999
  • To investigate the changes in the responses of vestibular neurons with time during vestibular compensation, the resting activity and dynamic responses of type I and II neurons in the medial vestibular nuclei to sinusoidal angular acceleration were recorded following unilateral labyrinthectomy (ULX) in Sprague-Dawley rats. The unitary extracellular neuronal activity was recorded from the bilateral medial vestibular nuclei with stainless steel microelectrodes of $3{\sim}5\;M{\Omega}$ before ULX, and 6, 24, 48, 72 hours, and 1 week after ULX under pentobarbital sodium anesthesia (30 mg/kg, i.p.). Gain (spikes/s/deg/s) and phase (in degrees) were determined from the neuronal activity induced by sinusoidal head rotation with 0.05, 0.1, 0.2, and 0.4 Hz. The mean resting activity before ULX was $16.7{\pm}8.6$ spikes/s in type I neurons $(n=67,\;M{\pm}SD)$ and $14.5{\pm}8.4$ spikes/s in type II neurons (n=43). The activities of ipsilateral type I and contralateral type II neurons to the lesion side decreased markedly till 24 hr post-op, and a significant difference between ipsilateral and contralateral type I neurons sustained till 24 hr post-op. The gain at 4 different frequencies of sinusoidal rotation was depressed in all neurons till 6 or 24 hr post-op and then increased with time. The rate of decrease in gain was more prominent in ipsilateral type I and contralateral type II neurons immediately after ULX. Although the gain of those neurons increased gradually after 24 hours, it remained below normal levels. The phase was significantly advanced in all neurons following ULX. These results suggest that a depression of activities in ipsilateral type I and contralateral type II neurons is closely related with the occurrence of vestibular symptoms and restoration of activities in those neurons ameliorates the vestibular symptoms.

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The Experimental Study of FOENICULI FRUCTUS on the Ischemic Cerebrovascular Disease (소회향이 허혈성 뇌혈관 질환에 미치는 실험적 연구)

  • Kim, Nam-Soon;Jeong, Hyun-Woo;Kang, Sung-Yung
    • Journal of Oriental Neuropsychiatry
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    • v.18 no.1
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    • pp.185-196
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    • 2007
  • Objective : This experimental Study was designed to investigate the effects of FOENICULI FRUCTUS(FF) on the change of inhibition lactate dehydrogenase(LDH) activity in neuronal cells and cytokines production in serum of cerebral ischemic rats. Method : FOENICULI FRUCTUS(FF)freeze dry powder and FF on the LDH activity in neuronal cells. Changes of FF on the physiological parameters(PaO2, PaCO2, MABP and HR) in crerbral ischemic rats. Effects of FF on the IL-1beta production, $TNF-{\alpha}$ production, $TGF-{\beta}$ production, and IL-10 in serum of cerebral ischemic rats. MCAO :. cytokines production of serum by drawing from femoral arterial blood after MCAO 1 hr. Reperfusion : cytokines production of serum by drawing from femoral arterial blood after reperfusion 1 hr. Results and Conclusion : 1. FF did not inhibit lactate dehydrogenase(LDH) activity in neuronal cells. 2. In serum by drawing from femoral arterial blood after middle cerebral arterial occlusion(MCAO) 1 hr and reperfusion 1 hr, sample group was significantly decreased $IL-l{\beta}$ production compared with control group 3. In serum by drawing from femoral arterial blood after MCAO 1 hr and reperfusion 1 hr, sample group was significantly decreased $TNF-{\alpha}$ production compared with control group. 4. In serum by drawing from femoral arterial blood after MCAO 1 hr and reperfusion 1 hr, sample group was significantly increased $TGF-{\beta}$ production compared with control group. 5. In serum by drawing from femoral arterial blood after reperfusion 1 hr, sample group was significantly increased IL-10 production compared with control group. This results were suggested that FF had inhibitive effect on the brain damage by inhibited LDH activity, $IL-l{\beta}$ and $TNF-{\alpha}$production, but accelerated $TGF-{\beta}$ production and IL-10 production.

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Effects of Resveratrol and trans-3,5,4'-Trimethoxystilbene on Glutamate-Induced Cytotoxicity, Heme Oxygenase-1, and Sirtuin 1 in HT22 Neuronal Cells

  • Kim, Dae-Won;Kim, Young-Mi;Kang, Sung-Don;Han, Young-Min;Pae, Hyun-Ock
    • Biomolecules & Therapeutics
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    • v.20 no.3
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    • pp.306-312
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    • 2012
  • Resveratrol (trans-3,5,4'-trihydroxystilbene) has received considerable attention recently for the potential neuroprotective effects in neurodegenerative disorders where heme oxygenase-1 (HO-1) and sirtuin 1 (SIRT1) represent promising therapeutic targets. Resveratrol has been known to increase HO-1 expression and SIRT1 activity. In this study, the effects of resveratrol and trans-3,5,4'-trimethoxystilbene (TMS), a resveratrol derivative, on cytotoxicity caused by glutamate-induced oxidative stress, HO-1 expression, and SIRT1 activation have been investigated by using murine hippocampal HT22 cells, which have been widely used as an in vitro model for investigating glutamate-induced neurotoxicity. Resveratrol protected HT22 neuronal cells from glutamate-induced cytotoxicity and increased HO-1 expression as well as SIRT1 activity in a concentration-dependent manner. Cytoprotection afforded by resveratrol was partially reversed by the specific inhibition of HO-1 expression by HO-1 small interfering RNA and the nonspecific blockage of HO-1 activity by tin protoporphyrin IX, but not by SIRT1 inhibitors. Surprisingly, TMS, a resveratrol derivative with methoxyl groups in lieu of the hydroxyl groups, and trans-stilbene, a non-hydroxylated analog, failed to protect HT22 cells from glutamate-induced cytotoxicity and to increase HO-1 expression and SIRT1 activity. Taken together, our findings suggest that the cytoprotective effect of resveratrol was at least in part associated with HO-1 expression but not with SIRT1 activation and, importantly, that the presence of hydroxyl groups on the benzene rings of resveratrol appears to be necessary for cytoprotection against glutamate-induced oxidative stress, HO-1 expression, and SIRT1 activation in HT22 neuronal cells.

Improvement of Neuronal Differentiation by PDE4 Inhibition in Human Bone Marrow-mesenchymal Stem Cells (인간 골수유래-중간엽 줄기세포(hBM-MSCs)에서 PDE4 억제조절을 통한 신경세포 분화 효율 개선)

  • Jeong, Da Hee;Joe, I-Seul;Cho, Goang-Won
    • Journal of Life Science
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    • v.26 no.12
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    • pp.1355-1359
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    • 2016
  • Human bone marrow mesenchymal stem cells (hBM-MSCs) can differentiate into various cell types including osteoblasts, adipocytes, chondrocytes, and myocytes. Previous studies, including our own, have shown that MSCs can also differentiate into neuron-like cells. However, their rate of neuronal differentiation is not sufficient for application to stem cell therapy, which requires well-defined cell types. For this purpose, we first examined the expression of neuronal lineage markers (GFAP, MAP-2, KCNH1, Nestin, NF-M, and Tuj-1) by real-time PCR, western blot, and immunocytochemical staining. The expressions of the astrocyte marker GFAP and neuronal markers NF-M and Tuj-1 increased in neuronal differentiated MSCs (dMSCs). To improve the neuronal differentiation efficiency, PDE4, an important signaling intermediator in the progression of neuronal differentiation, was modulated using well-known inhibitors such as rolipram or resveratrol and then differentiated into neuronal cells (Roli- or RSV-dMSCs). The expressions of NF-M, Tuj-1 were increased while that of GFAP decreased in Roli- and RSV-dMSCs, which were examined by real-time PCR, western blot, and immunocytochemical staining. From these experiments, we have found that the neuronal differentiation efficiency can be ameliorated by the modulation of PDE4 activity.

Studies on the Epitope of Neuronal Growth Inhibitory Factor (GIF) with Using of the Specific Antibody

  • Pang, Li-Yan;Ru, Bing-Gen
    • BMB Reports
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    • v.38 no.6
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    • pp.646-649
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    • 2005
  • Human neuronal growth inhibitory factor (GIF), a metalloprotein classified as metallothionein-3, is specifically expressed in mammal central nervous system (CNS). In these Studies the specific antibody to human GIF was prepared and used to search the epitope of human GIF by enzyme-linked immunosorbent assay (ELISA) and sequence comparison. The result of ELISA showed the epitope of human GIF may locate on a octapeptide (EAAEAEAE) in the $\alpha$-domain of human GIF, and the result of nerve cell culture indicated that the biological activity of GIF may be affected by the specific antibody.

Detection of Neuronal Activity by Motion Encoding Gradients: A Snail Ganglia Study

  • Park, Tae-S.;Park, Ji-Ho;Cho, Min-H.;Lee, Soo-Y.
    • Journal of Biomedical Engineering Research
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    • v.28 no.1
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    • pp.24-28
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    • 2007
  • Presuming that firing neurons have motions inside the MRI magnet due to the interaction between the neuronal magnetic field and the main magnetic field, we applied motion encoding gradients to dissected snail ganglia to observe faster responding MRI signal than the BOLD signal. To activate the snail ganglia in synchronization with the MRI pulse sequence, we used electrical stimulation with the frequency of 30 Hz and the pulse width of 2s. To observe the fast responding signal, we used the volume selected MRI sequence. The magnetic resonance signal intensity, measured with 8 ms long motion encoding gradient with a 20mT/m gradient strength, decreased about $3.46{\pm}1.48%$ when the ganglia were activated by the electrical stimulation.

Neuronal Cell Protection Activity of Macrolactin A Produced by Actinomadura sp.

  • Kim, Hyeon-Ho;Kim, Won-Gon;Ryoo, In-Ja;Kim, Chang-Jin;Suk, Jae-Eun;Han, Kyou-Hoon;Hwang, Se-Young;Yoo, Ick-Dong
    • Journal of Microbiology and Biotechnology
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    • v.7 no.6
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    • pp.429-434
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    • 1997
  • Macrolactin A, 24-membered macrolide, was isolated from the culture broth of Actinomadura sp. as a neuronal cell protecting substance. In the cell assay, this compound inhibited glutamate toxicity in N18-RE-105 cells with an $EC_50$ value of 0.5 ${\mu}g/ml.

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Influence of Daejowhan-gamibang on Antioxidative Effects and Apoptosis Induction in Neuronal Cells

  • Lee Young Chan;Choi Ho Seung;Lee Jun;Jeon Byung Hun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.18 no.6
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    • pp.1881-1891
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    • 2004
  • Daejowhan-gamibang(DJG) is used to prevention and treatment of cerebrovascular disease, heart disease, dementia, hyperlipdemia circulatory disturbance. Korean traditional herbal prescriptions and herb medicines in neuronal cells, which have been used for the treatment of stroke and brain diseases in Korean traditional medicine were screened to study the antioxidant effects and its mechanism. Daejowhan-gamibang water extract(DJGWE) was tested on their antioxidant activity using radical scavenging effects against ABTS. It showed significant antioxidant capacities at 50㎍ concentration. The antioxidant activity of DJGWE was determined in the different concentration (10㎍, 50 ㎍, and 100㎍). At the same time, the antiperoxidation effects was determined. Lipid peroxidation in brain homogenates induced by NADPH and ADP-Fe/sup 2+/ was significantly inhibited by DJGWE in vitro. DJGWE showed a potent antioxidant and antiperoxidative activity, further investigation, in vitro and in vivo, will be needed for the confirm of possibility as an antioxidant therapeutic agents and their optimal treatment of brain diseases in human. In searching the mechanism of antioxidant effects of DJGWE, it showed the inhibition of activity of JNK, p38, ERK and caspase 3 induced by hypoxia. So, DJGWE should be surveyed for the use of the potential therapeutic prescription for stroke and brain degenerative diseases such as pakinson's disease, dementia.

In vitro screening of the acetylcholinesterase inhibition, antioxidant activity, and neuronal cell protective effect of medicinal plant extracts (생약추출물의 acetylcholinesterase 저해, 항산화 및 신경세포보호 효과 in vitro 탐색)

  • Um, Min Young;Ha, Tae Youl;Seong, Ki Seung;Kim, Yong Sik
    • Food Science and Preservation
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    • v.20 no.6
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    • pp.840-845
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    • 2013
  • This study investigated the effects (i.e., the acetylcholinesterase activity, lipid peroxidation, and neuronal survival) of 20 kinds of medicinal water extracts. The water extracts of three medicinal plants - Cornus officinalis, Glycyrrhiza glabra, and Angelica gigas - were found to be the most effective on acetylcholinesterase inhibitory activity. In the lipid peroxidation-generating system induced by $H_2O_2/FeSO_4$ in rat brain homogenates, Perilla frutescens, Polygonum multiflorum, Cinnamomun cassia, and G. glabra exhibited protective activity against lipid peroxidation. The neuronal cell death induced by L-glutamate in PC12 was suppressed by the water extracts of G. glabra, Cinnamomun cassia, Platycodon grandiflorum, and Mentha arvensis at the concentration of $100{\mu}g/mL$. Taken together, these results showed that the water extract of G. glabra has the potential anti-dementia activity, which suggests that it might provide an effective strategy for improving dementia.