• Applied Microscopy
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• v.39 no.3
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• pp.261-266
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• 2009

This study aim to disclose a possible mechanism for the neuronal cell death induced by peripheral nerve injury following a spinal nerve ligation (SNL) as a neuropathic pain model. Male Sprague-Dawley rats (270~290 g) were used for this study. Pain threshold was evaluated for their response to mechanical (von Frey hairs) stimuli 1, 3, and 7 days after a tight ligation of L5 ventral ramus. In control group, the small ganglion cells were strongly stained with routine toluidine blue (TB), whereas the large ganglion cells showed a little bit weak stainity. Each large ganglion cell is surrounded by perineuronal satellite cells. In experimental groups, small ganglion cells showing apparent degenerative changes increased on 1 day, and showed a peak in degenerative cell number at 3 days group, and decreased gradually at 7 days group. We also found a small number of large-sized ganglion cells showing mild degenerative changes. However their satellite cells ware relatively intact with no typical findings throughout this experiment. Under the electron microscope, small ganglion cells showed various stage and typical features of the dark degeneration including mitochondrial swelling.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.1
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• pp.249-256
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• 1998

Glial fibrillary acidic proteins (GFAP) are a group of intermediate filaments that are distributed in the cytoplasm of glial cells. GFAP immunoreactivity (GFAP-IR) increase after central and peripheral nerve injuries. The purpose of this study was to determine change of GFAP-IR in rat trigeminal ganglion satellite cells following the axotomy of inferior alveolar nerve(IAN). The immunohistochemistry was carried out using the avidin-biotin-peroxidase complex(ABC) method. 1. Control group : Astrocytes in central root of trigeminal ganglion had strong GFAP-IR, but satellite cells of trigeminal ganglion occasionally had GFAP-IR. The patterns of reactivity in satellite cells of trigeminal ganglion were not concenturated in any specific region of trigeminal ganglion. 2. Three day group after IAN axotomy : There were highly GFAP-IR in satellite cells of trigeminal ganglion in mandibular region. GFAP-IR in maxillary and ophthalmic regions were less intense compared to mandibular region. 3. Seven day group after IAN axotomy : GFAP-IR that were increased compared to control group were seen in the mandibular region. But GFAP-IR were less intense compared to three day group. These results suggest that GFAP-IR increase in specific region of trigeminal ganglion following peripheral axotomy. therefore we suppose that GFAP study offer research tool in trigeminal neuralgia.

• Journal of Biomedical Engineering Research
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• v.28 no.2
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• pp.212-217
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• 2007

As a preliminary study for the development of electrical stimulation strategy of artificial retina, we set up a method fur the reconstruction of input intensity variation from retinal ganglion cell(RGC) responses. In order to estimate light intensity variation, we used an optimal linear filter trained from given stimulus intensity variation and multiple single unit spike trains from RGCs. By applying ON/OFF stimulation(ON duration: 2 sec, OFF duration: 5 sec) repetitively, we identified three functional types of ganglion cells according to when they respond to the ON/OFF stimulus actively: ON cell, OFF cell, and ON-OFF cell. Experiments were also performed using a Gaussian random stimulus and a binary random stimulus. The input intensity was updated once every 90 msec(i. e. 11 Hz) to present the stimulus. The result of reconstructing 11 Hz Gaussian and binary random stimulus was not satisfactory and showed low correlation between the original and reconstructed stimulus. In the case of ON/OFF stimulus in which temporal variation is slow, successful reconstruction was achieved and the correlation coefficient was as high as 0.8.

• Clinical and Experimental Otorhinolaryngology
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• v.11 no.4
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• pp.224-232
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• 2018

Objectives. Spiral ganglion neurons (SGNs) include potential endogenous progenitor populations for the regeneration of the peripheral auditory system. However, whether these populations are present in adult mice is largely unknown. We examined the presence and characteristics of SGN-neural stem cells (NSCs) in mice as a function of age. Methods. The expression of Nestin and Ki67 was examined in sequentially dissected cochlear modiolar tissues from mice of different ages (from postnatal day to 24 weeks) and the sphere-forming populations from the SGNs were isolated and differentiated into different cell types. Results. There were significant decreases in Nestin and Ki67 double-positive mitotic progenitor cells in vivo with increasing mouse age. The SGNs formed spheres exhibiting self-renewing activity and multipotent capacity, which were seen in NSCs and were capable of differentiating into neuron and glial cell types. The SGN spheres derived from mice at an early age (postnatal day or 2 weeks) contained more mitotic stem cells than those from mice at a late age. Conclusion. Our findings showed the presence of self-renewing and proliferative subtypes of SGN-NSCs which might serve as a promising source for the regeneration of auditory neurons even in adult mice.

• International Journal of Industrial Entomology and Biomaterials
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• v.3 no.2
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• pp.177-185
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• 2001

This study has been carried out to determine localization of Manduca sexta allatotropin (Mas-AT) neuropeptide in developing ventral nerve cord of the silk moth Bombyx mori with polyclonal antisera against Mas-AT. Suboesophageal ganglion (SOG) of the second to fifth instar larvae and 3-day-old pupae showed two to ten Mas-AT-immunoreactive (Mas-AT-IR) cell bodies. There were two to three pairs of labeled cell bodies in each thoracic ganglion (TG) from third instar larvae to adults, with the exception of TG from prepupae. One pair of labeled cell bodies was localized in each abdominal ganglion (AG) 1 to 6 from third instar larvae to 3-day-old pupae, whereas in 5-day-old pupae to adults there was one pair in a similar location of AG 1 to 5. The seventh neuromeres of terminal abdominal ganglia (TAG) from third instar Iarvae to 3- day-old pupae contained four labeled large cell bodies. In each of AG 1 to 7, these cell bodies showed similar allatotropin-immunoreactivity in appearance. Some labeled axons, projected from Mas-AT-lR cells in each of those AG, were extended to the nerves N 1 and N 2.

• Applied Microscopy
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• v.29 no.3
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• pp.303-313
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• 1999

In this paper, five kinds of neurosecretory cells-light green (LG) cell, dark green (DG) cell, caudo-dorsal (CD) cell, blue green (BG) cell, and yellow (Y) cell- and neuropils in the cerebral ganglion of the African giant snail, Achatina fulica, were observed with an electron microscope. The following results were obtained. The LG cells are circular or ovoid in shape, and about $60{\mu}m$ in size. The nucleus and cytoplasm of the LG cell look light due to their electron-low density. Large granular chromatins are evenly developed in the karyolymph, where round nucleoli are also found. In the cytoplasm, electron -high dense round granules of $0.4{\mu}m$ in average size are crowded. The DG cells are ovoid in shape, and $50\sim20{\mu}m$ in size. These relatively electron-high dense cells were rarely found. In their cytoplasm, cell organelles such as rough endoplasmic reticulum and mitochondria are found together with electron -high dense round granules of $0.2{\mu}m$ in average size. The CD cells are ellipsoidal cells densely distributed in caudo-dorsal parts of the cerebral ganglion. They have large nuclei compared with the cytoplasm. The developed granular heterochromatins are observed in the karyolymph, and lots of small round granules of $0.12{\mu}m$ in average size in the cytoplasm. The 3G cells, rarely found around endoneurium of the cerebral ganglion, take the shapes of long ellipses. They look dark due to their electron -high density. In the cytoplasm, small round granules of $0.1{\mu}m$ in average size are found. The Y cells are the smallest among the neurosecretory cells($9\times6.6{\mu}m$ in size). They are found mostly between the medio-dorsal parts and the caudo-dorsal parts of the cerebral ganglion. In the cytoplasm, tiny round granules of $0.08{\mu}m$ in average size form a group. The neuropils are found in the middle of the cerebral ganglion. In the axon ending, round granules with electron -high density ($0.07\sim0.03{\mu}m$ in diameter) and lucent vesicles ($0.03{\mu}m$ in diameter) are found in large quantities. They are excreted in the state of exocytosome formed by the invagination of the limiting membrane of the axon ending.

• Applied Microscopy
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• v.18 no.1
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• pp.92-102
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• 1988

The ototoxic effects of salicylate on the ultrastructure of spiral ganglion cells were examined. Sodium salicylate($50{\sim}60\/kg$ body weight, once a day for 7 days) were injected subcutaneously to $5{\sim}6$ week-old fifteen Sprague-Dawley rats. Animals were sacrificed 24 hours (group 1), 6 weeks (group 2) or 10 weeks (group 3) after the last injection. In group 1 animals, distention of membranous cisternae was found in the cytoplasm of ganglion cells, satellite cells and Schwann cells in which enlargement or multicystic cytosome formation of the mitochondria were shown. In group 2 animals, membranous cisternae became larger or fused to form larger vacuoles or cysts. Shrinkage of spiral ganglion cell cytoplasm and loosening of myelin sheath were seen. In group 3 animals, extensive swelling or loss of nerve fibers were shown along with the folding or partial loss of myelin sheath which caused leakage of ganglion cell cytoplasm. It was concluded that the ototoxicity of salicy-late caused the ultrastructral changes of the spiral ganglion cells which became more severe in group 2 and 3 animals. The possibility of retrograde degeneration following the sensory cell changes was suggested.

• The Journal of the Korean bone and joint tumor society
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• v.14 no.2
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• pp.178-181
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• 2008

In contrast to ganglion of the soft tissue, periosteal ganglion occurring within or beneath the periosteum is a rare disorder. The differential diagnosis includes periosteal chondroma, lipoma, giant cell tumor of tendon sheath and periosteal osteosarcoma. Most common location for periosteal ganglion is the tibia, followed by radius, femur and ulna. To our knowledge, only 1 case of periosteal ganglion of the fibula has been reported in the literature. We report a case of periosteal ganglion of the distal fibula in a thirty-year-old woman treated with excision of the cyst and the adjacent periosteum.

• Proceedings of the Korean Society of Life Science Conference
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• 2007.10a
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• pp.71.1-71.1
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• 2007

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• Anatomy and Cell Biology
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• v.51 no.4
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• pp.266-273
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• 2018

The ganglion cardiacum or juxtaductal body is situated along the left recurrent laryngeal nerve in the aortic window and is an extremely large component of the cardiac nerve plexus. This study was performed to describe the morphologies of the ganglion cardiacum or juxtaductal body in human fetuses and to compare characteristics with intracardiac ganglion. Ganglia were immunostained in specimens from five fetuses of gestational age 12-16 weeks and seven fetuses of gestational age 28-34 weeks. Many ganglion cells in the ganglia were positive for tyrosine hydroxylase (TH; sympathetic nerve marker) and chromogranin A, while a few neurons were positive for neuronal nitric oxide synthase (NOS; parasympathetic nerve marker) or calretinin. Another ganglion at the base of the ascending aorta carried almost the same neuronal populations, whereas a ganglion along the left common cardinal vein contained neurons positive for chromogranin A and NOS but no or few TH-positive neurons, suggesting a site-dependent difference in composite neurons. Mixtures of sympathetic and parasympathetic neurons within a single ganglion are consistent with the morphology of the cranial base and pelvic ganglia. Most of the intracardiac neurons are likely to have a non-adrenergic non-cholinergic phenotype, whereas fewer neurons have a dual cholinergic/noradrenergic phenotype. However, there was no evidence showing that chromogranin A- and/or calretinin-positive cardiac neurons corresponded to these specific phenotypes. The present study suggested that the ganglion cardiacum was composed of a mixture of sympathetic and parasympathetic neurons, which were characterized the site-dependent differences in and near the heart.