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ABSTRACT: Transient receptor potential vanilloid 4 (TRPV4) is a broadly expressed Ca(2+)-permeable cation channel in the vanilloid subfamily of transient receptor potential channels. It is activated by warm temperature, lipids downstream of arachidonic acid metabolism, hypoosmolarity, or mechanical stimulation. In the present study, we used SOD1(G93A) mutant transgenic mice as the animal model of amyotrophic lateral sclerosis (ALS) and investigated the changes of TRPV4 immunoreactivity in the central nervous system of these mice by immunohistochemical studies. An increased expression of TRPV4 was pronounced in the cerebral cortex, hippocampal formation, thalamus, cerebellum and spinal cord of symptomatic SOD1(G93A) transgenic mice. In the cerebral cortex, TRPV4 immunoreactivity was significantly increased in pyramidal cells of SOD1(G93A) transgenic mice. In the hippocampal formation, pyramidal cells of the CA1-3 areas and in the granule cells of the dentate gyrus demonstrated increased TRPV4 immunoreactivity. In addition, TRPV4 immunoreactivity was increased in the spinal cord, thalamus and cerebellum of the symptomatic SOD1(G93A) transgenic mice. This study, which showed increased TRPV4 in different brain and spinal cord regions of SOD1(G93A) transgenic mice, may provide clues to the understanding of many basic neuronal functions in ALS. These findings suggest a role for TRPV4 in the neuronal functions in ALS but the mechanisms and functional implications of increased TRPV4 require elucidation.
Journal of molecular histology 06/2012; · 1.75 Impact Factor
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ABSTRACT: In the present study, we performed immunohistochemical studies to investigate the changes of insulin-like growth factor binding
protein 2 (IGFBP2) in the central nervous system of SOD1G93A mutant transgenic mice as an in vivo model of amyotrophic lateral sclerosis (ALS). Decreased immunoreactivity for IGFBP2
was observed in the cerebral cortex, hippocampus and brainstem of SOD1G93A transgenic mice. In the cerebral cortex, the number of IGFBP2-positive cells was decreased in the somatomotor area, somatosensory
area, auditory area, visual area, entorhinal area, piriform area and prefrontal area. In the hippocampal formation, IGFBP2
immunoreactivity was significantly decreased in the CA1-3 areas and the dentate gyrus. In the brainstem, few IGFBP2-immunoreactive
cells were observed in the medullary and pontine reticular formation, vestibular nucleus, trigeminal motor nucleus, facial
nucleus, hypoglossal nucleus and raphe nucleus. In the spinal cord, IGFBP2 immunoreactivity was not significantly decreased
in SOD1G93A transgenic mice. This study showing decreased IGFBP2 in different brain regions of SOD1G93A transgenic mice may provide clues for understanding differential susceptibility of neural structures in ALS.
Journal of Molecular Histology 04/2012; 40(2):157-163. · 1.48 Impact Factor
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Yu Jin Cho,
Hyeon Suk Song,
Sukho Bhang,
Saehyoung Lee,
Bong Gu Kang,
Jae Chul Lee,
Jaeyeol An, Choong Ik Cha,
Do-Hyun Nam,
Byung Soo Kim,
Kyeung Min Joo
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ABSTRACT: Stem cell therapy is a promising approach for stroke. However, low survival rates and potential tumorigenicity of implanted cells could undermine the efficacy of the cell-based treatment. The use of stem cell-conditioned medium (CM) may be a feasible approach to overcome these limitations. Especially, specific stem cell culture condition and continuous infusion of CM into ischemic brains would have better therapeutic results. The CM was prepared by culturing human adipose-derived stem cells in a three-dimensional spheroid form to increase the secretion of angiogenic/neuroprotective factors. Ischemic stroke was induced by standard middle cerebral artery occlusion methods in the brain of 8-week-old Sprague-Dawley rats. Continuous infusion of CM or αMEM media (0.5 μl/hr) into the lateral ventricle was initiated 8 days after the surgery and maintained for 7 days. Alteration in the motor function was monitored by the rotarod test. Infarction volume and the number of microvessels or TUNEL-positive neural cells were analyzed 15 days after the surgery. Compared with αMEM, continuous CM infusion reduced the infarction volume and maintained motor function. The number of CD31-positive microvessels and TUNEL-positive neural cells significantly increased and decreased, respectively, in the penumbra regions. Although the apoptosis of all neural cell types decreased, reduction in the microglial apoptosis and astrogliosis was prominent and significant. In this study, the therapeutic effects of the CM against stroke were confirmed in an animal model. Increased endothelial cell proliferation, reduced neural cell apoptosis, and milder astrogliosis may play important roles in the treatment effects of CM.
Journal of Neuroscience Research 04/2012; 90(9):1794-802. · 2.74 Impact Factor
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ABSTRACT: Disease progression of amyotrophic lateral sclerosis (ALS) is partially mediated by the toxic microenvironment established by microglia. In the present study, we used SOD1G93A transgenic mice as an in vivo ALS model and replaced microglia expressing mutant SOD1 (mSOD1) with microglia expressing wild-type SOD1 (w/tSOD1) to modulate the toxic microenvironment. Stereotactic injection of Clodronate liposome, a selective toxin against the monocyte/macrophage system, into the fourth ventricle of the brains of 12-week-old asymptomatic ALS mice reduced the number of microglia effectively in the central nervous system. Subsequent bone marrow transplantation (BMT) with bone marrow cells (BMCs) expressing w/tSOD1 and GFP leads to replacement of the endogenous microglia of the ALS mice with microglia expressing w/tSOD1 and GFP. The expression of mSOD1 in the other neural cells was not influenced by the replacement procedures, and immunological side effects were not observed. The replacement of microglia significantly slowed disease progression and prolonged survival of the ALS mice compared with the ALS mice treated by stereotactic injection of PBS-liposome and BMT with BMCs expressing mSOD1 or w/tSOD1. These results suggest that replacement of microglia would improve the neural cell microenvironment, thereby slowing disease progression. The mechanisms and functional implications of this replacement require further elucidation.
Biochemical and Biophysical Research Communications 02/2012; 418(2):359-65. · 2.48 Impact Factor
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ABSTRACT: SIRT1, which is a mammalian homolog of yeast nicotinamide adenine dinucleotide-dependent deacetylase silent information regulator 2 (SIR2), is the best-characterized SIRT family member. SIRT1 regulates longevity in several model organisms and is involved in several processes in mammalian cells, including cell survival, differentiation, and metabolism. In the present study, we used SOD1(G93A) mutant transgenic mice as an in vivo model of amyotrophic lateral sclerosis (ALS) and performed immunohistochemical studies, RT-PCR and western blotting analysis in order to investigate the changes of SIRT1 immunoreactivity in the central nervous system of these mice. An increased expression of SIRT1 was obvious in the cerebral cortex, hippocampal formation, thalamus and spinal cord of symptomatic SOD1(G93A) transgenic mice. In the cerebral cortex, SIRT1 immunoreactivity was significantly increased in pyramidal cells of SOD1(G93A) transgenic mice. In the hippocampal formation of these mice, SIRT1 immunoreactivity was increased in the pyramidal cells of the CA1-3 areas and in the granule cells of the dentate gyrus. In addition, SIRT1 immunoreactivity was increased in the spinal cord and thalamus of symptomatic SOD1(G93A) transgenic mice. This study, which showed increased SIRT1 in different brain regions of SOD1(G93A) transgenic mice, may provide clues to the understanding of selective neuronal loss in ALS. These findings suggest a role for SIRT1 in the motor functions in ALS but the mechanisms and functional implications of increased SIRT1 require elucidation.
Brain research 11/2011; 1433:20-8. · 2.46 Impact Factor
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ABSTRACT: Nitric oxide (NO) modulates the activities of various channels and receptors to participate in the regulation of neuronal intracellular Ca(2+) levels. Ca(2+) binding protein (CaBP) expression may also be altered by NO. Accordingly, we examined expression changes in calbindin-D28k, calretinin, and parvalbumin in the cerebral cortex and hippocampal region of neuronal NO synthase knockout(-/-) (nNOS(-/-)) mice using immunohistochemistry. For the first time, we demonstrate that the expression of CaBPs is specifically altered in the cerebral cortex and hippocampal region of nNOS(-/-) mice and that their expression changed according to neuronal type. As changes in CaBP expression can influence temporal and spatial intracellular Ca(2+) levels, it appears that NO may be involved in various functions, such as modulating neuronal Ca(2+) homeostasis, regulating synaptic transmission, and neuroprotection, by influencing the expression of CaBPs. Therefore, these results suggest another mechanism by which NO participates in the regulation of neuronal Ca(2+) homeostasis. However, the exact mechanisms of this regulation and its functional significance require further investigation.
Anatomy & cell biology 06/2011; 44(2):106-15.
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ABSTRACT: The aim of present study is to investigate more functional neural stem cells (NSCs) could be isolated from brains with amyotrophic lateral sclerosis (ALS) and expanded in vitro, based on previous reports demonstrating de novo neurogenesis is enhanced to replace degenerating neural tissue.
Thirteen- or eighteen-week-old mutant human Cu/Zn superoxide dismutase (SOD1(G93A)) transgenic ALS and wild-type SOD1 transgenic control mice were utilized. Changes in numbers of NSCs in the dentate gyrus were analyzed by immunohistochemistry against nestin and CD133. NSCs were primarily cultured from hippocampus of ALS or control mice. Expression of NSC markers, in vitro expansion capacity, and differentiating potential were compared.
Hippocampus of 13-week-old pre-symptomatic ALS mice harbor more cells that can be propagated for more than 12 passages in vitro, compared with same age control mice. Primarily-cultured cells formed neurospheres in the NSC culture medium, expressed NSC markers, and differentiated into cells with differentiated neural cell characteristics in the differentiation condition confirming that they are NSCs. In contrast, long-term expansible NSCs could not be derived from brains of 18-week-old symptomatic ALS mice with the same experimental techniques, although they had comparable nestin-immunoreactive cells in the dentate gyrus.
These results would suggest that increased neuroregeneration in early phase of ALS could be translated to regenerative approaches; however, long-term exposure to ALS microenvironments could abolish functional capacities of NSCs.
Neurological Research 01/2011; 33(1):33-7. · 1.52 Impact Factor
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ABSTRACT: Pituitary adenylate cyclase-activating peptide (PACAP) and vasoactive intestinal peptide (VIP) have been implicated in a large array of physiological and patho-physiological processes through their receptors (VPAC(1), VPAC(2), and PAC(1) receptor) in the central nervous system. Previously, we demonstrated age-related decreases in VPAC(1) receptor expression in the rat brain providing a possible basis of several age-induced functional changes in the aged brain. In the current study, we also examined age-related changes in PAC(1) and VPAC(2) receptors in aged rat brains using an immunohistochemical approach. We found that PAC1 immunoreactivity was significantly increased in the hippocampal formation, hypothalamus, thalamus, midbrain septal nuclei, and white matter of aged rats compared with young control rats although its distribution pattern was not altered. In contrast, both distribution pattern and immunoreactivity of VPAC(2) receptor remained unchanged in aged rat brains. These results suggest that the PACAP/VIP receptors exhibit specific expressional changes in the aged brain and that these specific changes could underlie age-associated memory and cognitive functional declines as well as several other age-induced functional changes in the brain. However, the exact regulatory mechanism and its functional significance require further elucidation.
Brain research 09/2010; 1351:32-40. · 2.46 Impact Factor
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ABSTRACT: Nitric Oxide (NO) actively participates in the regulation of neuronal intracellular Ca(2+) levels by modulating the activity of various channels and receptors. To test the possibility that modulation of Ca(2+) buffer protein expression level by NO participates in this regulatory effect, we examined expression of calbindin-D28k, calretinin, and parvalbumin in the cerebellum of neuronal NO synthase knock-out (nNOS((-/-))) mice using immunohistochemistry. We observed that in the cerebellar cortex of the nNOS((-/-)) mice, expression of calbindin-D28k and parvalbumin were significantly increased while expression of calretinin was significantly decreased. These results suggest another mechanism by which NO can participate in the regulation of Ca(2+) homeostasis.
Anatomy & cell biology 03/2010; 43(1):64-71.
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ABSTRACT: In the present study, we used the SOD1(G93A) mutant transgenic mice as an in vivo model of amyotrophic lateral sclerosis (ALS) and performed immunohistochemical studies to investigate the changes of insulin-like growth factor-binding protein 4 (IGFBP4) in the central nervous system. Decreased expression of IGFBP4 was obvious in the cerebral cortex, hippocampus, cerebellar cortex and inferior olive of SOD1(G93A) transgenic mice. In the cerebral cortex, there was a significant decrease in IGFBP4 immunoreactivity in the pyramidal cells. In the hippocampal formation, IGFBP4 immunoreactivity was also decreased in the pyramidal cells of CA1-3 areas and the granule cells of dentate gyrus. In the cerebellar cortex, IGFBP4 immunoreactivity was prominent in the granular layer in wtSOD1 transgenic mice, compared to that in SOD1(G93A) transgenic mice. IGFBP4 immunoreactivity was decreased in the inferior olive of SOD1(G93A) transgenic mice. This study, showing decreased IGFBP4 in different brain regions of SOD1(G93A) transgenic mice, may provide clues to understanding the differential susceptibility of neural structures in ALS, suggesting a role of IGFBP4 in an abnormality of cognitive and/or motor function in ALS. The mechanisms and functional implications of these decreases require elucidation.
Annals of anatomy = Anatomischer Anzeiger: official organ of the Anatomische Gesellschaft 09/2008; 190(6):502-9. · 0.88 Impact Factor
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ABSTRACT: Although neural stem cell (NSC) transplantation has been investigated as a promising tool for reconstituting damaged brains, recent evidences suggest that NSCs may rescue the brain via paracrine effects rather than by direct cell replacements. In this study, we attempted to determine the neuroprotective effect of NSC-conditioned media (NSC-CM) in in vitro model of Huntington's disease. Cerebral hybrid neurons (A1) were transfected with either wild-type huntingtin (18 CAG repeats) or mutant huntingtin (100 CAG repeats). At 24h after the transfection, immunocytochemical patterns of the huntingtin aggregations, as well as the level of N-terminal proteolytic cleavages of huntingtin were analyzed. Neuronal apoptosis was evaluated with flowcytometry after Annexin-V and propidium iodide (PI) staining. Cerebral hybrid neurons transfected with mutant huntingtin showed five aggregates patterns, including diffuse cytoplasmic, dispered vacuoles, perinuclear vacuoles, nuclear inclusions (NI), and cytoplasmic inclusions (CI). NSC-CM reduced the levels of nuclear and cytoplasmic inclusions. The transfection with mutant huntingtin increased the level of N-terminal cleavages, which was reduced by the NSC-CM treatment. In addition, NSC-CM reduced the Annexin-V(+)PI(+) and Annexin-V(+)PI(-) neurons which were induced by the mutant huntingtin transfection. In summary, NSC-CM was neuroprotective in in vitro model of Huntington's disease with modulating mutant huntingtin-induced cytotoxicity.
Neuroscience Letters 05/2008; 435(3):175-80. · 2.11 Impact Factor
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ABSTRACT: In the present study, we examined the localizations of canonical transient receptor potential channels (TRPCs) in rat basal ganglia. The dot-like staining pattern of TRPC5 was observed through the globus pallidus (GP) and caudate-putamen. TRPC7 had a strikingly high level of expression in the neuropil in the GP. In the subthalamic nucleus, strong staining for TRPC5 was observed in the cell bodies, while moderate to high immunoreactivies for TRPC1, TRPC3, TRPC4 and TRPC7 were found in the cell bodies and surrounding neuropil. In the substantia nigra, immunoreactivities for TRPC3 and TRPC7 were prominent in the cell bodies and several processes in the pars compacta and pars reticulata. TRPC6 was expressed in the neuropil, not in the cell bodies. This study may provide useful data for the future investigations on the structural and functional properties of TRPCs.
Neuroscience Letters 08/2007; 422(1):18-23. · 2.11 Impact Factor
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Bong Sun Kang,
Jin-Young Ahn,
Min Ky Kim,
Hyun-Jeong Kim,
Lami Kang,
Hun-Chang Lim,
Kyung-Sook Park,
Jae-Seon Lee,
Jeong-Sun Seo, Choong Ik Cha,
Seung U Kim,
Yoon Jeong Park,
Manho Kim
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ABSTRACT: Huntington's disease is caused by CAG trinucleotide expansions in the gene encoding huntingtin. N- terminal fragments of huntingtin with polyglutamine produce aggregates in the endosome-lysosomal system, where proteolytic fragments of huntingtin is generated. Heat shock protein 70 (HSP70) prevents the formation of protein aggregates, but the effect of HSP70 on the huntingtin in the endosome-lysosomal system is unknown. This study was to determine whether HSP70 alters the distribution of huntingtin in endosome-lysosomal system. HSP70 expressing stable cells (NIH/3T3 or cerebral hybrid cell line A1) were generated, and mutant [(CAG)(100)] huntingtin was transiently overexpressed. Analysis of subcellular distribution by immunocytochemistry or proteolysis cleavage by Western blotting was performed. 18 CAG repeat wild type [WT; (CAG)(18)] huntingtin was used as a control. Cells with huntingtin showed patterns of endosome-lysosomal accumulation, from a "dispersed vacuole (DV)" type into a coalescent "perinuclear vacuole (PV)" type over time. In WT huntingtin, HSP70 increased the cells with the PV types that enhanced the proteolytic cleavage of huntingtin. However, HSP70 reduced cells of the DV and PV types expressing mutant huntingtin, that result in less proteolysis than that of control. In addition, intranuclear inclusions were formed only in mutant cells, which was not affected by HSP70. These results suggest that HSP70 alters the distribution of huntingtin in the endosome- lysosomal system, and that this contributes to huntingtin proteolysis.
Experimental and Molecular Medicine 03/2007; 39(1):38-46. · 2.48 Impact Factor
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ABSTRACT: Although glycogen synthase kinase 3beta (GSK3beta) is emerging as a prominent drug target in the treatment of neurodegenerative diseases such as Alzheimer's disease (AD) and stroke, very little is known about age-related changes in GSK3beta expression and GSK3beta phosphorylation. Therefore, we examined age-related changes in immunoreactivities for GSK3beta and phosphorylated GSK3beta (pGSK3beta) in the central nervous system. In aged rats, there were significant increases in GSK3beta immunoreactivity in the cell bodies and processes of pyramidal cells in most cortical regions. GSK3beta immunoreactivity was also significantly increased in the pyramidal layer of CA1-3 regions, and the granule cell layer of dentate gyrus. Age-related increases were prominent in lateral septal nuclei, compared to the medial septal nuclei. Interestingly, both GSK3beta and pGSK3beta was increased in the prefrontal cortex, while GSK3beta and pGSK3beta was differentially localized in the cerebellar cortex. The first demonstration of age-related alterations in immunoreactivities for GSK3beta and pGSK3beta in the basal forebrain area and cholinergic projection targets may provide useful data for investigating the pathogenesis of age-related neurodegenerative diseases including AD.
Neuroscience Letters 01/2007; 409(2):134-9. · 2.11 Impact Factor
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ABSTRACT: In the present study, we examined patterns of A-myb expression in the kainic acid (KA)-treated mouse hippocampus. Western blot analysis revealed that A-myb expression was dramatically increased in brain 3 days after KA treatment, and was sustained for more than 7 days. A-myb immunoreactivity was restricted to hippocampal neurons in control mice. Three days after KA treatment, strong A-myb immunoreactivity was observed in reactive astrocytes throughout the CA3 region. Thereafter, A-myb immunoreactive astrocytes gradually concentrated around the CA3 region in parallel with selective neuronal loss, and only a few A-myb immunoreactive astrocytes persisted in the CA3 region 14 days after KA treatment. These findings suggest that the A-myb plays a role in the reactive gliosis signaling pathway in KA-induced excitotoxic lesions.
Neurochemical Research 12/2006; 31(11):1371-4. · 2.24 Impact Factor
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ABSTRACT: Corticotropin releasing factor (CRF) is known to be involved in the stress response and in some degenerative brain disorders. In addition, CRF has a role as a neuromodulator in adult cerebellar circuits. Data from developmental studies suggest a putative role for CRF as a trophic factor during cerebellar development. In this study, we investigated the trophic role for CRF family of peptides by culturing cerebellar neurons in the presence of CRF, urocortin or urocortin II. Primary cell cultures of cerebella from embryonic day 18 mice were established, and cells were treated for either 1, 5 or 9 days with Basal Medium Eagles complete medium alone or complete medium with 1 microM CRF, urocortin, or urocortin II. The number of GABA-positive neurons in each treatment condition was counted at each culture age for monitoring the changes in neuronal survival. Treatment with 1 microM CRF or 1 microM urocortin increased the survival of GABAergic neurons at 6 days in vitro and 10 days in vitro, and this survival promoting effect was abolished by treatment with astressin in the presence of those peptides. Based on these data, we suggest that CRF or urocortin has a trophic role promoting the survival of cerebellar GABAergic neurons in cultures.
Journal of Korean Medical Science 07/2006; 21(3):518-26. · 0.99 Impact Factor
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ABSTRACT: In the present study, we performed immunohistochemistry using antibodies directed against TRPCs to study the localizations of these channels in rat hippocampus. The pyramidal cell bodies of CA1-3 areas and the granule cell bodies of the dentate gyrus were immunoreactive for TRPC1, TRPC3, TRPC4 and TRPC5. On the other hand, TRPC6 exhibited the cloud-like neuropil staining only in the molecular layer of the dentate gyrus. As a whole, the present study has clearly shown the localization of TRPCs in rat hippocampus and may provide useful data for the future investigations on the structural and functional properties of TRPCs.
Brain Research 05/2006; 1085(1):132-7. · 2.73 Impact Factor
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ABSTRACT: Lipid rafts provide a platform for regulating cellular functions and participate in the pathogenesis of several diseases. However, the role of caveolin-1 in this process has not been elucidated definitely in neuron. Thus, this study was performed to examine whether caveolin-1 can regulate amyloid precursor protein (APP) processing in neuronal cells and to identify the molecular mechanisms involved in this regulation. Caveolin-1 is up-regulated in all parts of old rat brain, namely hippocampus, cerebral cortex and in elderly human cerebral cortex. Moreover, detergent-insoluble glycolipid (DIG) fractions indicated that caveolin-1 was co-localized with APP in caveolae-like structures. In DIG fractions, beta APP secretion was up-regulated by caveolin-1 over- expression, which was modulated via protein kinase C (PKC) in neuroblastoma cells. From these results we conclude that caveolin-1 is selectively expressed in senescent neurons and that it induces the processing of APP by beta-secretase via PKC downregulation.
Experimental and Molecular Medicine 05/2006; 38(2):126-33. · 2.48 Impact Factor
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ABSTRACT: In this study, we examined expressional changes of VPAC1 receptor in aged rat brains using an immunohistochemical approach and found that its immunoreactivities are significantly reduced in the cerebral cortex, hippocampal region, and amygdala of aged rats. These results suggest that this reduction could underlie aging-associated memory/learning deficits and several other age-induced functional changes in these areas. However, the functional consequences of these down-regulations require further elucidation.
Brain Research 01/2006; 1064(1-2):166-72. · 2.73 Impact Factor
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Min Kyu Kim,
Joo Hyun Park,
Bum Sun Kwon,
Kyeung Min Joo,
Jung-Soo Pyo,
Young Hee Cheon,
Tai-Kyong Baik, Choong Ik Cha,
Sa Sun Cho,
Seon Young Nam,
Byung Lan Lee
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ABSTRACT: Our findings suggest that the aging process induces changes in the phenotype of olfactory supporting cells in the rat.
To investigate age-related changes in the expression of astroglial intermediate filament proteins in the olfactory supporting cells of the rat.
The expression of nestin and glial fibrillary acidic protein (GFAP) in the olfactory epithelium (OE) of young (3 months) and aged (25 months) Sprague-Dawley rats was compared using Western blotting and immunohistochemistry.
Western blot analysis showed nestin expression only in the young OE, whereas GFAP was detected only in the aged OE. Immunohistochemistry showed that GFAP was localized in the olfactory supporting cells of the aged OE, with regional differences.
Acta Oto-Laryngologica 09/2005; 125(8):883-7. · 1.08 Impact Factor
