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

• YAKHAK HOEJI
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• v.39 no.4
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• pp.444-449
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• 1995

Primary cultures of rat cortical and chicken embryonic brain cells were employed to establish a reliable screening method for natural products blocldng or enhancing glutamate-induced neurotoxicity. Exposure of primary cultured rat cortical cells or chicken embryonic brain cells to high dose of glutamate resulted in the fragmentation of neutites and consequent neuronal death. The level of cytoplasmic lactate dehydrogenase(LDH), indicator for cell survival in cultures, was significantly reduced at exposure to glutamate. For the practical application of the methods, series of concentrations of plants extracts and positive control were applied prior to the glutamate insult on primary cultures of rat cortical and chicken embryonic, brain cells. Relative LDH level in cells was measured for the estimation of the effect of the test materials on the glutamatergic neurons. The validity of the present screening method for natural products acting on glutamatergic neurons was examined with dextromethorphan, a known glutamatergic antagonist. The treatment of 100 $\mu{M}$ dextromethorphan prevented the reduction of LDH in rat cortical and chicken embryonic brain cells caused by glutamate insult keeping 60% and 90% of LDH level in normal control, respectively. Above results indicate that primary cultures of rat cortical and chicken embryonic brain cells could be proper systems for the screening of potential natural agents acting on glutamatergic, neurons. Between the two types of cultures, primary culture of chicken embryonic brain cells seemed to be a better system for the primary screening, since it is technically easier and economical compared to that of rat cortical cells.

• Proceedings of the Ginseng society Conference
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• 1998.06a
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• pp.12-20
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• 1998

Primary neuronal culture was studied for observing effect of ginsenoside Rgl (Rgl) on serum-free medium induced apoptosis. Results showed that Rgl at concentration of 1 umol$.$ L-1 and 10 umol$.$L-1 could inhibit apoptosis, decrease intracellular calcium concentration in cultured cortical neurons, enhance SOD activity in both aged rat cortex and cultured cortical neurons, scavenge cytotoxic oxygen free radicals, decrease NO content and NOS activity in aged rat cortex and cultured cortical neurons, increase bel-2 gene expression in rat brain. These results provided new data for elucidating the anti-aging effect of Rgi. Rgl is considered to be a useful drug for treatment of Alzheimer's disease and brain aging.

• YAKHAK HOEJI
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• v.38 no.4
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• pp.401-409
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• 1994

The cholinergic activity of dammarane glycosides of Panax ginseng was examined both morphologically and chemically on primary cultures of chicken embryonic brain cells. When primary cultured chicken embryonic cells were treated with $50\;{\mu}g/ml$ of total dammarane glycosides of Panax ginseng followed by the exposure to 10mM atropine for 48 hr, lactate dehydrogenase levels within the cells remained at 36% of untreated control values while atropine-treated controls fell to 0% lactate dehydrogenase. It was found that cholinergic activity was mainly exerted by the panaxadiol glycosides. The treatment of the cells with $50\;{\mu}g/ml$ of panaxadiol glycosides followed by the exposure to atropine, lactate dehydrogenase levels within the cells remained at 60% of untreated control values. Ginsenoside $Rb_1$, a component of panaxadiol glycosides, was found to exert the cholinergic activity keeping the lactate dehydrogenase levels within the cells at 70% of untreated control values. The cholinergic activity of ginsenoside $Rb_1$ seems to be exerted through acting on the $Ca^{2+}$ channel in cultured brain cells.

• Molecules and Cells
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• v.25 no.4
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• pp.538-544
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• 2008

Activity-dependent local translation in the dendrites of brain neurons plays an important role in the synapse-specific provision of proteins necessary for strengthening synaptic connections. In this study we carried out combined fluorescence in situ hybridization (FISH) and immunocytochemistry (IC) and showed that more than half of the eukaryotic elongation factor 1A (eEF1A) mRNA clusters overlapped with or were immediately adjacent to clusters of PSD-95, a postsynaptic marker, in the dendrites of cultured rat hippocampal neurons. Treatment of the neurons with KCl increased the density of the dendritic eEF1A mRNA clusters more than two-fold. FISH combined with IC revealed that the KCl treatment increased the density of eEF1A mRNA clusters that overlapped with or were immediately adjacent to PSD-95 clusters. These results indicate that KCl treatment increases both the density of eEF1A mRNA clusters and their synaptic association in dendrites of cultured neurons.

• Archives of Pharmacal Research
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• v.17 no.5
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• pp.343-347
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• 1994

Effects of betaine on glutamate-induced neurotoxicity were examined on primary culturs of chicken embryonic brain cells and on rat cortical cultures. Betaine was found to attenuate glutamate-induced neurotoxicity both morphologically and biochemically. A 30 min exposure of chicken embryonic brain cells cultured for 12 days to 500 .mu.M glutamate produced wide-spread acute neuronal swelling and neurtic fragmentation. A 2-h pretreatment of cultured chicken embryonic brain cells with i mM betaine prior to a 30 min exposure to 500 , mu, M glutamate significantly raised the survival rate of neurons in the culture. When chicken embryonic brain cells were pretreated for 2 h with i mM betaine followed by exposure to 100 .mu.M glutamate for 42 h, lactate dehydrogenase levels within the cells remained at 62% of .mu.M untreated control values while glutamate-treated control fell to 0% lactate dehydrogenase. Betaine also exerted attenuating effects on N-methyl-D-asparte-, kainate-and quisqualate-induced neurotoxicity in a similar manner to that observed with glutamate. Similar neuroprotective effects of betaine with rat cortical cultures.

• Korean Journal of Medicinal Crop Science
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• v.20 no.1
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• pp.8-15
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• 2012

The present study investigated an ethanol extract of Chaenomeles sinensis fruit (CSF) for possible neuroprotective effects on neurotoxicity induced by amyloid ${\beta}$ protein ($A{\beta}$) (25-35) in cultured rat cortical neurons and also for antidementia activity in mice. Exposure of cultured cortical neurons to $10{\mu}M\;A{\beta}$ (25-35) for 36 h induced neuronal apoptotic death. At $0.1-10{\mu}g/m{\ell}$, CSF inhibited neuronal death, elevation of intracellular calcium concentration ($[Ca^{2+}]_i$), and generation of reactive oxygen species (ROS) induced by $A{\beta}$ (25-35) in primary cultures of rat cortical neurons. Memory loss induced by intracerebroventricular injection of mice with 15 nmol $A{\beta}$ (25-35) was inhibited by chronic treatment with CSF (10, 25 and 50 mg/kg, p.o. for 7 days) as measured by a passive avoidance test. CSF (50 mg/kg) inhibited the increase of cholinesterase activity in $A{\beta}$ (25-35)-injected mice brain. From these results, we suggest that the antidementia effect of CSF is due to its neuroprotective effect against $A{\beta}$ (25-35)-induced neurotoxicity and that CSF may have a therapeutic role for preventing the progression of Alzheimer's disease.

• The Journal of Korean Medicine
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• v.24 no.3
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• pp.72-83
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• 2003

Objective : The goal of the present study was to investigate the protective effect of Gamiheechum-tang (Jiaweixiqian-tang; GHCT) on brain tissue damage from chemical or ischemic insults. Methods : Levels of cultured cortical neuron death caused by toxic chemicals were measured by LDH release assay. Neuroprotective effects of GHCT on brain tissues were examined in vivo by ischemic model of middle cerebral artery (MCA) occlusion. Results : Animal groups treated with GBCT showed significantly decreased hypertension, and reduced levels of aldosterone, dopamine, and epinephrine in the plasma. GHCT treatments ($l0-200\mu\textrm{g}/ml$) significantly decreased cultured cortical neuron death mediated by AMPA, kainate, BSO, or Fe2+ when measured by LDH release assay. Yet, cell death mediated by NMDA was effectively protected by GHCT at the highest concentration examined ($200\mu\textrm{g}/ml$). In the in vivo experiment examining brain damage by MCA occlusion, affected brain areas by ischemic damage and edema were significantly less in animal groups administered with GHCT compared to the non-treated control group. Neurological examinations of forelimbs and hindlimbs showed that GHCT treatment improved animals' recovery from ischemic injury. Moreover, the extent of injury in cortical and hippocampal pyramidal neurons in ischemic rats was much reduced by GHCT, whose morphological features were similarly observed in non-ischemic animals. Conclusion : The present data suggest that GBCT may play an important role in protecting brain tissues from chemical or ischemic injuries.

• Biomolecules & Therapeutics
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• v.29 no.2
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• pp.144-153
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• 2021

Astrocytes play various important roles such as maintaining brain homeostasis, supporting neurons, and secreting inflammatory mediators to protect the brain cells. In aged subjects, astrocytes show diversely changed phenotypes and dysfunctions. But, the study of aged astrocytes or astrocytes from aged subjects is not yet sufficient to provide a comprehensive understanding of their important processes in the regulation of brain function. In this study, we induced an in vitro aged astrocyte model through late passage cultivation of rat primary cultured astrocytes. Astrocytes were cultured until passage 7 (P7) as late passage astrocytes and compared with passage 1 (P1) astrocytes as early passage astrocytes to confirm the differences in phenotypes and the effects of serial passage. In this study, we confirmed the morphological, molecular, and functional changes of late passage astrocytes showing aging phenotypes through SA-β-gal staining and measurement of nuclear size. We also observed a reduced expression of inflammatory mediators including IL-1β, IL-6, TNFα, iNOS, and COX2, as well as dysregulation of wound-healing, phagocytosis, and mitochondrial functions such as mitochondrial membrane potential and mitochondrial oxygen consumption rate. Culture-conditioned media obtained from P1 astrocytes promoted neurite outgrowth in immature primary cultures of rat cortices, which is significantly reduced when we treated the immature neurons with the culture media obtained from P7 astrocytes. These results suggest that late passage astrocytes show senescent astrocyte phenotypes with functional defects, which makes it a suitable model for the study of the role of astrocyte senescence on the modulation of normal and pathological brain aging.

• Applied Microscopy
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• v.35 no.4
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• pp.10-15
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• 2005

Cultured neurons from Drosophila brain on a glass coverslip to understand the structural basis of synapse were prepared for TEM observations. Neurons on a coverslip were fixed, dehydrated and embedded in Epon without separating from coverslip. After polymerization, the block was placed in 49% hydrofluoric acid to remove the coverslip. The block was examined under a light microscope to select exact neurons, then trimmed and sectioned for TEM observation.