• Animal cells and systems
• /
• v.1 no.4
• /
• pp.589-594
• /
• 1997

The neuronal voltage-sensitive calcium channels (VSCCs) are multisubunit complexes consisting of $\alpha_1,\;\alpha_2-\delta$ and $\beta$ subunits. Heterologous expression and biochemical studies have shown that the activity of VSCCs is regulated by their $\beta$ subunits in a $\beta$ subunit isoform-specific manner. To elucidate the $\beta$ subunit identity of the P/Q-type calcium channel encoded by an $\alpha_{1A}$ subunit, which is exclusively expressed in the Purkinje and granule cell of the cerebellum, we have examined the spatial and temporal expression patterns of $\beta$ subunits and compared them with those of $\alpha_{1A}$ subunit in the developing rat cerebellum. Reverse transcriptase- polymerase chain reaction (RT-PCR) and Northern blot analysis have shown that $\beta_4$ subunit mRNA was prominently expressed in the cerebellum and much more abundant than any other distinct $\beta$ subunits. RNase protection assay has further demonstrated that the expression of $\alpha_{1A}$ and $\beta_4$ subunits increased during cerebellar development, while the amount of $\beta_2$ and $\beta_3$ mRNAs did not significantly change. In addition, a $\beta_4$ transcript was present in cultured cerebellar granule cells, but not in astrocyte cells, and the level of $\beta_4$ mRNA expression increased gradually in vitro seen as in vivo. Based on the spatial and temporal expression patterns of $\beta_4$ subunit, we conclude that $\beta_4$ may predominantly associate, but probably not exclusively, with the $\alpha_{1A}$ subunit in rat cerebellar granule cells.

• Toxicological Research
• /
• v.13 no.3
• /
• pp.251-256
• /
• 1997

Toluene inhalation increases glutamate level and its receptor in various brain regions. In this study, nitric oxide synthase (NOS) activities were investigated in various rat brain regions using NADPH diaphorase staining method which examined histochemical changes of NOS in the neural cells. Also, in vitro LDH leakage assay and MTT test were performed to investigate the toxic influences of toluene in cultured granule cell of rat cerebellum which was significantly affected with toluene in vivo. Rats were exposed to toluene of 10000 ppm for 3 days. 7 days and 14 days by 20 min $\times$ 2 times a day. NADPH diaphorase staining was processed in the different brain regions after inhalation. NADPH diaphorase staining density was not significantly changed at 3 days inhalation group, but the density decreased in proportion to the duration of toluene inhalation. Over 30% of staining density was decreased at 14 days group which was maximum duration of inhalation in this study. The tendency of staining density decrease was significant in granule cell of cerebellum. Cell death by toluene exposure was observed in cultured cerebellar granule cell. $EC_{50}$ measured with LDH leakage assay and MTT test were 43 mM and 72 mM respectively.

• Archives of Pharmacal Research
• /
• v.19 no.2
• /
• pp.132-136
• /
• 1996

Exogenously applied oxygen free radical generating agent, pyrogallol, highly elevated extracellular glutamate accumulation and augmented N-methyl-D-aspartate (NMDA)-induced glutamate accumulation in cerebellar granule neuronal cells, but did not in astrocytes. Superoxide dismutase remarkably decreased the pyrogallol-induced glutamate accumulation, but either NMDA or kainate antagonists did not. In addition, pyrogallol did not affect the NMDAinduced intracellular calcium elevation. Pyrogallol partially blocked glutamate uptake into astrocytes. These results suggest that oxygen free radicals elevate extracellular glutamate accumulation by stimulating the release of glutamate as well as blocking the glutamate uptake.

• Journal of Electrochemical Science and Technology
• /
• v.12 no.3
• /
• pp.297-301
• /
• 2021

Microbial fuel cells (MFCs) convert chemical energy to electrical energy via electrochemically active microorganisms. The interactions between microbes and the surface of a carbon electrode play a vital role in capturing the respiratory electrons from bacteria. Therefore, improvements in the electrochemical and physicochemical properties of carbon materials are essential for increasing performance. In this study, a microwave and sulfuric acid treatment was used to modify the surface structure of graphite granules. The prepared expandable graphite granules (EGG) exhibited a 1.5 times higher power density than the unmodified graphite granules (1400 vs. 900 mW/m³). Scanning electron microscopy and Fourier transform infrared spectroscopy revealed improved physical and chemical characteristics of the EGG surface. These results suggest that physical and chemical surface modification using sulfuric acid and microwave heating improves the performance of electrode-based bioprocesses, such as MFCs.

• Animal cells and systems
• /
• v.15 no.4
• /
• pp.268-273
• /
• 2011

Transgenic mice expressing green fluorescent protein (GFP) under the control of human glial fibrillary acidic protein promoter (hGFAP) have been utilized for in vivo labeling of astrocytes. Although it has been considered that virtually all astrocytes express GFP in this transgenic mouse, we found that different subsets of GFAP-expressing astrocytes express considerably different levels of GFP in the adult brain. Astrocytes in the spinal cord, the molecular layer of thecerebellum, meninges, white matter, corpus callosum and blood vessels exhibited strong GFP, whereas subsets of astrocytes associated with granule cells in the cerebellum and dentate gyrus did not or only marginally exhibited GFP. We also found that a small subset of GFP-expressing cells in the periglomeruli of the olfactory bulb did not express GFAP immunoreactivity. Collectively, these results suggest that human GFAP promoter-derived GFP expression does not faithfully recapitulate the endogenous GFAP expression in mice, suggesting that upstream regulatory mechanisms controlling GFAP transcription are different in different populations of astrocytes, and may reflect the functional diversity of astrocytes.

• Applied Microscopy
• /
• v.20 no.1
• /
• pp.1-16
• /
• 1990

The epidermal tissue of Korean planaria Phagocata vivida(Ijima et Kaburaki) is composed of the simple columnar epithelium. The ventral epidermis of this animals is thinner than the dorsal epidermis and has a furrow in the median line in which dark cell is observed. The clear cells which are electron-lucent are located either side of the dark cells. Those are compactly covered with long cilia. The free surface of the latero-ventral epidermis is tightly contacted with the earth and this epidermal free surface has a great number of short cilia, and a lot of C-type of basophilic granule cell are migrated into the cytoplasm of epithelium from mesenchyme passing through the basement membrane and then this granules are put out of latero-ventral free surface. Dorsal epidermis is thickest among the whole epidermis of these animals and the rhabdite granules are more distributed in dorsal epidermis than in ventral epidermis. According to the cytochemical and ultrastructural research, composed epidermis of this planaria are divided into nine type cells, that is, ciliated columnar epithelium, dark cell, mucous cell, rhabdite-forming cell, sunk round cell, A type, B type, C type and D type of basophilic granule cell.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.27 no.6
• /
• pp.759-763
• /
• 2013

This experiment was performed to investigate whether 50% ethanol extracts of the combined-preparation of Longanae Arilus, Chrysanthemi Flos, Zizyphi Fructus and Ginseng Radix alba (CPE) has hypnotic effects and/or enhances pentobarbital-induced sleeping time. Locomotor activity was evaluated using a ambulometer of tilting-type. The sedative-hypnotic effects were evaluated by measuring the sleeping onset time and sleeping time in pentobarbital-treated mice 30 min. after oral administration of CPE and muscimol. The intracellular $Cl^-$ concentration of cerebellar granule cells was estimated using $Cl^-$ sensitive fluorescence probe N-(ethoxycarbonylmethyl)-6-methoxyquinolinium (MQAE). CPE (150 mg/kg) decreased the locomotor activity, but CPE itself did not induce sleep. However, CPE reduced sleeping onset and prolonged sleeping time induced by pentobarbital (42 mg/kg). In addition, CPE (2 ${\mu}g/ml$) and pentobarbital (2.5 ${\mu}M$) itself did not affect on the chloride influx in primary cultured cerebellar granule cells, but the combination of CPE and pentobarbital (2.5 ${\mu}M$) increased the chloride influx onto the cells. In conclusion, it is suggested that CPE might augment pentobarbital-induced sleep through the increase of chloride influx.

• Applied Microscopy
• /
• v.21 no.1
• /
• pp.77-85
• /
• 1991

The virus maturation in fat body cells infected with P. rapae granulosis virus were also examined to have the following results. Thin section of P. rapae GV granules showed a regular lattice of the granule enclosing virus particles. Virus particles were observed to penetrate the fat body cells by fusion or viropexis type. The blood and fat body cells uptaked the granulosis viruses a phagosome, in which they were digested by lysosomal enzymes.

• Korean Journal of Veterinary Research
• /
• v.33 no.4
• /
• pp.573-577
• /
• 1993

The pancreatic endocrine cells, glucagon and somatostation, of the Korean tree squirrel. Sciurus vulgais corea, were investigation by means of light and electron microscopic immunohistochemistry using the PAP and protein A-gold techniques. Glucagon-immunoreactive cells were distributed the periphery and occasinonaly central region of the pancreatic islets. Also, isolated cell was found between the pancreatic ancinar cells. The glucagon cells contraine granules with a diameter of 240~320nm and the electron dense core usually surrounded by a halo of less dense granular material. The core of granule was labelled strongly with gold particles. Somatostatin-immunoreactive cells were weakly stained in scattered along the peripheral pancreatic islets and were distributed as singly or small groups with in the pancreatic acinar cells. The somatostatin cells were spherical with a diameter of 250~275nm, moderately electron opaque (Gold particles were mostly demonstrated on the entire granule.

• Korean Journal of Environmental Agriculture
• /
• v.16 no.1
• /
• pp.48-54
• /
• 1997

This study was performed to develop the biological treatment technology of wastewater polluted with heavy metals. The copper-tolerant bacteria, Pseudomonas stutzeri which possessed the ability to accumulate copper, was isolated from mine wastewaters polluted with various heavy metals. The characteristics of copper accumulation in the cells and the recovery of the copper from the cells accumulating zinc, were investigated. Removal rate of copper from the solution containing 100mg/l of copper by copper-tolerant bacteria was more than 78% at 2 days after inoculation with the cells. A large number of the electron-dense granules were found mainly on the cell wall and cell membrane fractions, when determined by transmission electron microscopy. Energy dispersive X-ray spectroscopy revealed that the electron-dense granules were copper complex with the substances binding copper. The copper accumulated into the cells was not desorbed by deistilled water, but more than 80% of the copper accumulated was desorbed by 0.1M-EDTA solution. The residues of the cells after combustion at $550^{\circ}C$ amounted to about 23.2% of the dry weight of the cells. EDS analysis showed that residues were relatively pure copper compound containing more than 78.4% of copper.