• Toxicological Research
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• v.13 no.4
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• pp.401-408
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• 1997

Adult male ICR mice were exposed to methylmercuric chloride (CH$_3$HgCI) through drinking water for 80 days. The distribution of mercury in the kidney, liver, spleen and cerebellum of the mouse was examined according to a autometallographic silver-enhancement technique based on a physical development process which renders mercury deposit visible. Grains of mercury traces were located in the proximal convoluted tubules. Lesser staining of the grains was seen in the collecting tubules of medulla. The glomerular basement membrane was void. In the liver, mercury accumulations were present primarily in the hepatocytes around portal area containing interlobular bile duct, artery and portal vein. Also grains of mercury traces were accumulated in the white pulp of the spleen and Purkinje cell layer of the cerebellum.

• Applied Microscopy
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• v.48 no.4
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• pp.110-116
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• 2018

Since a transmembrane protein, TMEM16A, also called anoctamin 1 (ANO1), was identified as a bona fide calcium ($Ca^{2+}$)-activated chloride ($Cl^-$) channel (CaCC), there have been many reports on its expression and function. However, limited information on ANO1 expression and function in the brain is still available. In this study, we tried to reexamine expression patterns of ANO1 in the mouse cerebellum and further characterize ANO1-expressing components by immunohistochemical analyses. Strong ANO1 immunoreactivity was observed as large puncta in the granule cell layer and weak to moderate immunoreactivities were observed as small puncta in the molecular and Purkinje cell layers. Double-label experiments revealed that ANO1 did not colocalize with cerebellar neuronal population markers, such as anti-calbindin and anti-NeuN, while it colocalized or intermingled with a presynaptic marker, anti-synaptophysin. These results demonstrate that ANO1 is mainly localized at presynaptic terminals in the cerebellum and involved in synaptic transmission and modulation in cerebellar information processing.

• Applied Microscopy
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• v.35 no.1
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• pp.31-39
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• 2005

Synapses are contact points where one neuron communicates with another. The morphological change of synapses under various physiological or pathological conditions has long been hypothesized to modify their functional properties. 3-dimensional (3-D) reconstruction of synapses with serial ultrathin sections has contributed to the understanding of ultrastructural dimensions and compositions of synapses. The 3-D reconstruction procedures, however, require a great amount of expertise as well as include prohibitively timeconsuming processes. Here, we introduce efficient 3-D reconstruction technique using high-voltage electron microscopy (HVEM). Primarily, we established an optimal section thickness and staining condition to observe synaptic structures in detail under HVEM. The result showed that synaptic profiles were preserved at the section thickness of 250 nm without the overlapping of synaptic ultrastructures. An increase in the reaction time of en bloc staining was most efficient to enhance contrast than the extension of postembedding staining or the addition of uranyl acetate during dehydration. Then, 3-D reconstruction of parallel fiber-Purkinje cell synapses in the rat cerebellum was carried out with serial HVEM images and reconstruction software. The images were aligned and the contours of synapses were outlined on each section. 3-D synapses were finally extracted from the section files by grouping all the synaptic contours. The reconstructed synapse model clearly demonstrated the configuration of pre and postsynaptic components. These results suggest that 3-D reconstruction of synapses using HVEM is much efficient and suitable for massive quantitative studies on synaptic connectivity than conventional TEM approach using numerous ultrathin sections.

• Molecules and Cells
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• v.26 no.2
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• pp.186-192
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• 2008

NELL2, a neural tissue-enriched protein, is produced in the embryo, and postembryonically in the mammalian brain, with a broad distribution. Although its synthesis is required for neuronal differentiation in chicks, not much is known about its function in the adult mammalian brain. We investigated the distribution of NELL2 in various regions of the adult rat brain to study its potential functions in brain physiology. Consistent with previous reports, NELL2-immunoreactivity (ir) was found in the cytoplasm of neurons, but not in glial fibrillary acidic protein (GFAP)-positive glial cells. The highest levels of NELL2 were detected in the hippocampus and the cerebellum. Interestingly, in the cerebellar cortex NELL2 was observed only in the GABAergic Purkinje cells not in the excitatory granular cells. In contrast, it was found mainly in the hippocampal dentate gyrus and pyramidal cell layer that contains mainly glutamatergic neurons. In the dentate gyrus, NELL2 was not detected in the GFAP-positive neural precursor cells, but was generally present in mature neurons of the subgranular zone, suggesting a role in this region restricted to mature neurons.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2001.10a
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• pp.14-17
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• 2001

Positional clonging (map-based cloning) of mutations or genetic variations has been served as an invaluable tool to understand in-vivo functions of genes and to identify molecular components underlying phenotypes of interest. Mice homozygous for the cerebellar deficient folia (cdf) mutation are ataxic, with cerebellar hypoplasia and abnormal lobulation of the cerebellum. In the cdf mutant cerebellum approximately 40% of Purkinje cells are ectopically located within the white matter and the inner granule cell layer (IGL). To identify the cdf gene, a high-resolution genetic map for the cdf-gene-encompassing region was constructed using 1997 F2 mice generated from C3H/HeSnJ-cdf/cdf and CAST/Ei intercross. The cdf gene showed complete linkage disequilibrium with three tightly linked markers D6Mit208, D6Mit359, and D6Mit225. A contig using YAC, BAC, and P1 clones was constructed for the cdf critical region to identify the gene. A deletion in the cdf critical region on chromosome 6 that removes approximately 150 kb of DNA selection. cdf mutant mice with the transgenic copy of the identified gene restored the brain abnormalities of the mutant mice. The positional cloning of cdf gene provides a good example showing the identification of a gene could lead to finding a new component of important molecular pathways.

• Proceedings of the KSAR Conference
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• 2001.10a
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• pp.14-17
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• 2001

Positional cloning (map-based cloning) of mutations or genetic variations has been served as an invaluable tool to understand in-vivo functions of genes and to identify molecular components underlying phenotypes of interest. Mice homozygous for the cerebellar deficient folia (cdf) mutation are ataxic, with cerebellar hypoplasia and abnormal lobulation of the cerebellum. In the cdf mutant cerebellum approximately 40% of Purkinje cells are ectopically located within the white matter and the inner granule cell layer (IGL). To identify the cdf gene, a high-resolution genetic map for the cdf-gene-encompassing region was constructed using 1997 F2 mice generated from C3H/HeSnJ-cdf/cdf and CAST/Ei intercross. The cdf gene showed complete linkage disequilibrium with three tightly linked markers D6Mit208, D6Mit359, and D6Mit225. A contig using YAC, BAC, and P1 clones was constructed for the cdf critical region to identify the gene. A deletion in the cdf critical region on chromosome 6 that removes approximately 150kb of DNA was identified. A gene associated with this deletion was identified using cDNA selection. cdf mutant mice with the transgenic copy of the identified gene restored the brain abnormalities of the mutant mice. The positional cloning of cdf gene provides a good example showing the identification of a gene could lead to finding a new component of important molecular pathways.

• PNF and Movement
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• v.5 no.1
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• pp.9-17
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• 2007

Purpose : The purpose of this study was to test the effect of balance training for proprioceptive and vestibular sensory stimulation and therapeutic environment on expression of BDNF after traumatic brain injury in the rat. Subject : Twelve Sprague-Dawley rats were randomly assigned into group I and group II. After traumatic brain injury, group I was housed in standard cage for 7 days. Group II was housed in therapeutic cage after balance training for 7 days. Method : Traumatic brain injury was induced by weight drop model and after operation they were housed in individual standard cages for 24 hours. After 7th day, the rats were sacrificed and cryostat coronal sections were processed individually in goat polyclonal anti-BDNF antibody. The morphologic characteristics and the BDNF expression were investigated in injured hemisphere section from immunohistochemistry using light microscope. Result : Immunohistochemical response of BDNF in lateral nucleus, purkinje cell layer, superior vestibular nucleus and pontine nucleus appeared very higher in group II than in group I Conclusion : The present result revealed that simultaneously application of balance training for proprioceptive and vestibular sensory stimulation input and therapeutic environment in traumatic brain injured rats is enhance expression of BDNF and it is facilitates neural plasticity.

• Experimental and Molecular Medicine
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• v.50 no.11
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• pp.8.1-8.14
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• 2018

We previously demonstrated that the direct transplantation of human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) into the dentate gyrus ameliorated the neurological symptoms of Niemann-Pick type C1 (NPC1)-mutant mice. However, the clinical presentation of NPC1-mutant mice was not fully understood with a molecular mechanism. Here, we found 14,15-epoxyeicosatrienoic acid (14,15-EET), a cytochrome P450 (CYP) metabolite, from hUCB-MSCs and the cerebella of NPC1-mutant mice and investigated the functional consequence of this metabolite. Our screening of the CYP2J family indicated a dysregulation in the CYP system in a cerebellar-specific manner. Moreover, in Purkinje cells, CYP2J6 showed an elevated expression level compared to that of astrocytes, granule cells, and microglia. In this regard, we found that one CYP metabolite, 14,15-EET, acts as a key mediator in ameliorating cholesterol accumulation. In confirming this hypothesis, 14,15-EET treatment reduced the accumulation of cholesterol in human NPC1 patient-derived fibroblasts in vitro by suppressing cholesterol synthesis and ameliorating the impaired autophagic flux. We show that the reduced activity within the CYP system in the cerebellum could cause the neurological symptoms of NPC1 patients, as 14,15-EET treatment significantly rescued cholesterol accumulation and impaired autophagy. We also provide evidence that the intranasal administration of hUCB-MSCs is a highly promising alternative to traumatic surgical transplantation for NPC1 patients.

• Journal of Life Science
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• v.25 no.9
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• pp.1043-1050
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• 2015

Glutamate is one of the principle transmitters in the CNS. Ionotropic receptors of glutamate, selectively activated by N-methyl-D-aspartate (NMDA), play an important role in the processes of cell development, learning, memory, and etc. On the other hand, many studies discovered that over-activation of glutamate receptors leads to neurodegeneration and are known to be implicated in major areas of brain pathology. Any sustained effect of a transient NMDA receptor activation is likely to involve signaling to the nucleus and to trigger coordinated changes in gene expression. Classically, a set of immediate-early genes are induced first; some of genes are by themselves transcription factors that control expression of other target genes. This study provides understanding of changes of inducible transcription factors mRNA levels with RT-PCR by inducing over-activation of NMDA receptor with intraperitoneal NMDA injection. The experimental conditions were varied by 1, 5, 25, and 125 g/ of body weight NMDA and measured transcription factors mRNA levels are Egr-1, c-Jun, JunB, and FosB. Based on result obtained, inducible transcription factors mRNA in NMDA injection to mice with 5 g/body weight showed the greatest change. And ITF mRNA showed greatest change 24 hr after injection. The expression level of JunB mRNA was markedly changed. Up to the present days, no study clearly understood how ITF mRNA affected the apoptosis of purkinje cells in the cerebellum. The current study improves the understanding of the mechanism of apoptosis of purkinje cells in the cerebellum.

• Journal of International Academy of Physical Therapy Research
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• v.1 no.2
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• pp.91-98
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• 2010

This study is intended to examine the motor skill learning and treadmill exercise on motor performance and synaptic plasticity in the cerebellar injured rats by harmaline. Experiment groups were divided into four groups and assigned 15 rats to each group. Group I was a normal control group(induced by saline); Group II was a experimental control group(cerebellar injured by harmaline); Group III was a group of motor skill learning after cerebellar injured by harmaline; Group IV was a group of treadmill exercise after cerebellar injured by harmaline. In motor performance test, the outcome of group II was significantly lower than the group III, IV(especially group III)(p<.001). In histological finding, the experimental groups were destroy of dendrities and nucleus of cerebellar neurons. Group III, IV were decreased in degeneration of cerebellar neurons(especially group III). In immunohistochemistric response of synaptophysin in cerebellar cortex, experimental groups were decreased than group I. Group III's expression of synaptophysin was more increased than group II, IV. In electron microscopy finding, the experimental groups were degenerated of Purkinje cell. These result suggest that improved motor performance by motor skill learning after harmaline induced is associated with dynamically altered expression of synaptophysin in cerebellar cortex and that is related with synaptic plasticity.