Effect of BMI1 Knockdown on Cell Proliferation, Apoptosis, Invasiveness, and Migration of U251 Glioma Cells / 체질인류학회지

BMI1 belongs to the polycomb-repressive complex 1 (PRC1) family of genes that are conserved chromatin silencers. These are essential for maintaining both the normal and cancerous stem cell state. In this study, we evaluated the effect of siRNA-mediated BMI1 knockdown on tumor cell properties such as invasion, migration, and apoptosis, as well as on cell signaling pathways responsible for tumor progression in the human glioma cell line, U251. Knockdown of BMI1 induced apoptosis by activating cleavage of PARP and caspase-3. It also decreased the expression of anti-apoptotic proteins, survivin, XIAP, Bcl-xL, and Mcl1. Additionally, BMI1 knockdown significantly decreased cell invasion and cell migration ability. BMI1 knockdown also decreased the phosphorylation of Akt/FOXO1/3a signaling proteins. Our results suggest that BMI1 knockdown induces apoptosis and decreases cell invasion and cell migration. Moreover, we believe these phenomenona are associated with decreased phoshorylation of Akt signaling proteins, which contributes to cancer progression.

Morphological Changes in Vasopressin-immunoreactive Neurons in the Hypothalamus of the Aged Rats / 체질인류학회지

The role of neuropeptides in the central nervous system (CNS) has received increasing attention. Numerous peptide molecules are found in the mammalian CNS and many of them are thought to act as either neurotransmitters or neuromodulators. The neuropeptides found in high concentration in the hypothalamus include vasopressin (VP), vasoactive intestinal polypeptide, somatostatin, and oxytocin. The main approches to assess the involvement of neuropeptides can be focused on functions affecting the aging of the brain. Morphological aging of the CNS has been characterized by degenerative changes of fiber connections and cell loss, although degeneration does not always occur to the same extent throughout various parts of the brain and, moreover, varies for different cell types. Despite of many studies in VP containing neurons , there exist discrepancies in results about the changes of aged rat brain. The aim of the present study is, therefore, to investigative possible changes in the number and morphology of VPimmunoreactive neurons with aging in each area of the hypothalmus of the aged rats. As a result, the number of VP-immunoreactive neurons was decreased in hypothalamus nucleus of aged group. Especially, in VP-immunoreactive neurons of hypothalamus, the size of neuronal cell body and nuclei in aged group is larger than in young group and the fiber density of immunoreactivity neurons of median eminance (ME) in aged group is stronger than in young group. But, the total number of VP-immunoreactive neurons in the suprachiasmatic nucleus (SCN) of the aged group is larger than in the young group. These studies indicate the involvement of VP-immunoreactive neurons in aging process of hypothalamus, and aging process may affect the synthesis of VP in the neurons of hypothalamic nuclei. Whereas, in VP expression, aging process induces an enlargement of the cell size of surviving neurons to compensate.

Human Umbilical Cord Blood Infusion in Paralyzed Rats: Histologic and Behavioral Alterations / 대한척추외과학회지

STUDY DESIGN: Experimental animal study OBJECTIVES: To examine the ability of human umbilical cord blood (hUCB) stem cells to target a zone of injury and to determine the efficacy of hUCB cells to ameliorate the behavioral deficits after a hUCB cell infusion in paralyzed rats. SUMMARY OF LITERTURE: Many groups have investigated the use of stem cells as potential treatments for a CNS injury. hUCB cells have recently been reported to alleviate the behavioral consequences of a stroke injury. MATERIALS AND METHODS: Thirty Sprague Dawley rats were divided into 6 groups (Gr) (Gr 1. SCI (spinal cord injury) + hUCB delivered at one day postinjury, Gr 2. SCI + hUCB delivered at 3 days postinjury, Gr 3. SCI + hUCB delivered at 5 days postinjury, Gr 4. laminectomy + hUCB, Gr 5. SCI only, Gr 6. Laminectomy only). SCI was produced by compressing the spinal cord to the level of the 8-9th thoracic spine for 1 minute with an aneurysm clip that was calibrated to a closing pressure of 50 gms. The hUCB cells (0.5 ml, 1.5x106) were administered intravenously to the rats. The rat was assessed behaviorally at one, two and three weeks using the BBB behavioral scale. Four weeks after the injury, the animals were sacrificed and the hUCB positiveresponse neural cells (mouse anti-human mitochondria monoclonal antibody=MAB 1273) at the injury level observed using optical and fluorescent microscopy. RESULTS: MAB 1273 positive cells were observed in groups 1, 2 and 3 but not in groups 4, 5 and 6. In particular, there were 870 cells distributed over an area of 1.2 mm(2) in group 3. Group 3 showed the most significant recovery over time in the open field exam, and the most improvement in another tests of incline, leg extension, and toe spread compared with group 1 (p<0.01). CONCLUSION: After infusing the hUCB stem cells to SCI rats, it was confirmed that hUCB cells migrate to an injured area and ameliorate the behavioral deficits. A hUCB infusion 5 days after the injury produced best results in terms of the number of cells and motor recovery.

Effects of the Human-Mesenchymal Stem Cells Transplantation on Spinal Cord Injury of the Rats / 대한해부학회지

Two sources of adult stem cells that have aroused great interest are human bone marrow-derived mesenchymal stem cells (hMSCs) and human umbilical cord blood cells. hMSCs have been reported to maintain their ability to differentiate into neuronal lineage cells in the central nervous system. Therefore, transplantation of hMSCs represents an attractive new form of cellular therapy for clinical application in spinal cord injury (SCI). The aim of this study was to investigate how transplanted hMSCs from the venous circulation moved into a target zone of compression injury in the spinal cord of rats, and if they ameliorated the behavioral impairments associated with SCI. SCI in rats was induced by compressing the spinal cord for 30 s with an aneurysm clip. hMSCs labeled with cholera toxin subunit B conjugated to fluorescein isothiocyanate (CTX B-FITC) were injected intravenously through the tail vein or directly on the SCI site using a 27-g needle. Suspensions of hMSCs collected from adult humans were delivered at concentrations (1x10(6)cells/200 microliter) in 1 or 5 d after experimental SCI. After transplantation of hMSCs, the SCI regions displayed some endogenous background fluorescence, but CTX B-FITC-labeled hMSCs were clearly identifiable. They were observed in injured but not in intact areas; they were usually round or slightly elongated with a prominent nucleus. Only a few hMSCs were found in the spinal cord in each case but there were more cells in the rats injected at day one than at day five. This study confirmed that these were indeed transplanted hMSCs using antisera recognizing human-specific nuclei or human-specific mitochondria. Double immunofluorescence analysis showed the production of some neuronal and glial cell markers in the SCI lesions. Behavioral test scores of SCI rats treated with hMSCs at day one were significantly better than those for rats treated at day five and for the untreated SCI group. Thus, hMSCs appear to be beneficial in reversing the behavioral effects of SCI in this rat model, even when infused one day after injury. They might be a viable source of stem cells for the treatment of human neurological disorders.

Effect of Chronic Alcohol Intake on Vasopressin and Oxytocin-containing Neurons in the Paraventricular and Supraoptic Nucleus of the Rat Hypothalamus / 체질인류학회지

Chronic alcohol intake can profoundly modify the neuronal activity and the morphologic structure of hypothalamic nucleus in the rat brain. The aim of the present study is to observe the effects of chronic alcohol intake on expression of vasopressin and oxytocin in the paraventricular and supraoptic nucleus in the rat hypothalamus. Experimental rats (n=14) were divided into control group and chronic alcohol group. Chronic alcohol group was induced via daily liquid alcohol intake for 6 months beginning at 8 weeks of age. As a result, the number of vasopressin and oxytocin-containing neurons was decreased in the paraventricular and supraoptic nucleus in chronic alcohol group. Especially, the number of vasopressin-containing neurons of chronic alcohol group was significantly decreased in the paraventricular nucleus. Chronic alcohol intake produced significant changes in the volume of the cell bodies and their nucleus in neurons of the paraventricular and supraoptic nucleus. Particularly, the size of nucleus of vasopressin-containing neurons in chronic alcohol group was larger than in control group. These results show that chronic alcohol intake may affect the synthesis of vasopressin and oxytocin in the neurons of hypothalamic nuclei. Whereas, chronic alcohol intake induces an enlargement of the cell size of surviving neuron to compensate.

Effect of Maternal Thyroxine Treatment on the Postnatal Development of Brain-derived Neurotrophic Factor-containing Neuron in the Brain of Pups of Alcohol Abused Mother / 대한해부학회지

Maternal alcohol abuse is thought to be the common cause of mental retardation. Especially, continuous alcohol consumption during critical period of brain development induce fetal alcohol effects. In this study, the authors investigated the effects of maternal alcohol drinking on the postnatal changes of BDNF contents and patterns of BDNF-containing neuron in neonatal rat brain, and, the influence of maternal thyroxine treatment on the brain of pups of alcohol abused mother. Pregnant rats were divided into three groups. Alcohol-fed group (n=4) received 35 calories of liquid alcohol diet daily from gestation day 6; control pair-fed group (n=4) was fed a liquid diet in dextrin replaced alcohol isocalorically; alcohol+T4 group (n=4) received 35 calories liquid alcohol diet and exogenous thyroxine (5 microgram/kg/day) subcutaneously. The amount of BDNF was significantly higher in the alcohol+T4 group as compared to the alcohol group at P7, P14 and P21, especially, alcohol+T4-exposed pups showed a significant increase of BDNF at P7. The decrease in BDNF was found in alcohol group compared to control pair-fed group at all ages. In alcohol+T4 group, BDNF-containing Purkinje cells exhibited mature pattern and monolayer arrangement at P14. Alcohol+T4 group showed mature pattern and numerical increase of BDNF-containing cells in cerebral cortex, hypothalamus and hippocampus at P7. The BDNF immunoreactivity of hippocampus continued to show prominent configuration in alcohol+T4 group at P28. These results indicate that the increase of the BDNF-containing neurons and BDNF amount in pups of thyroxinesupplemented alcohol-exposed dams as compared to control pair-fed and alcohol-exposed pups at P7, presumably suggest the early postnatal growth stimulatory effect of the exogenously supplemented thyroxine. Therefore, the increase of BDNF synthesis caused by maternal administration of exogenous thyroxine may ameliorate fetal alcohol effects, one of the ill effects as a result of the dysthyroid state following maternal alcohol abuse.

Effect of Exogenous Thyroxine on the Postnatal Development of Serotonin-containing Neuron in Fetal Alcohol Effects in the Rat Raphe Nuclei / 체질인류학회지

Serotonin (5-hydroxytryptamine, 5-HT) has been concerned in the pathophysiology of various neuropsychiatric disorders. It is known to modulate emotion, cognition, endocrine activity, motor function, and pain. In the present study, the effects of exogenous thyroxine (T4) on the postnatal development of serotonin-containing neuron in the rat raphe nuclei with fetal alcohol effects were investigated using immunohistochemistry. These experimental animals were divided into three groups : the alcohol-fed group received 35 calories liquid ethanol diet; the control pair-fed group was fed a liquid diet in dextrin replaced alcohol isocalorically; alcohol+T4 group received alcohol diet and exogenous thyroxine subcutaneously. After the pups were born, the pups of each were fostered by surragate mother. An average of four pups, one from each litter, were killed at days 0, 7, 14, 21, and 28 for each of the above three groups. As a result, in alcohol group, serotonin-immunoreactivity was weakly stained at all postnatal ages compared to control pair-fed and alcohol+T4 group. The intensity of serotonin immunoreactivity was more prominent in alcohlol+T4 group than in control pair-fed group at P0. Mature patterns of serotonin-containing neurons were observed in control pair-fed and alcohol+T4 group at P7. A similar developmental pattern of serotonin-containing neuron was observed on and after P7 in control pair-fed and alcohol+T4 group. These results suggest that the increase of serotonin synthesis during early postnatal life caused by maternal administration of exogenous thyroxine may ameliorate fetal alcohol effects, one of the ill effects as a result of the dysthyroid state following maternal alcohol abuse.

Effect of Maternal Thyroxine Treatment on the Postnatal Development of Brain-derived Neurotrophic Factor-containing Purkinje Cell in Fetal Alcohol Effects in the Rat Cerebellum / 체질인류학회지

Maternal alcohol abuse is thought to be the common cause of mental retardation. Even moderate maternal alcohol consumption may produce fetal alcohol effects with behavioral and learning difficulties, if the drinking is associated with malnutrition. Especially, continuous alcohol consumption during critical period of brain development is very likely to produce fetal alcohol effects. The aims of this study are to investigate whether exogenous thyroxine treatment to alcohol -fed dams may ameliorate the detrimental effects of alcohol on the postnatal development of BDNF -containing Purkinje cell of the cerebellar cortex of the offspring. The morphological features of the growth and maturation were observed at 0, 7, 14, 21, 28 postnatal days via immunohistochemistry. In addition, electron microscopic finding of BDNF -containing Purkinje cell at P14 was also examined. Time -pregnant rats were divided into three groups. Alcohol -fed group received 35 calories of liquid alcohol diet daily from gestation day 6; control pair -fed group was fed a liquid diet in which dextrin replaced alcohol isocalorically; alcohol +/-T4 group received 35 calories liquid alcohol diet and exogenous thyroxine subcutaneously. As a result, a similar developmental pattern of BDNF -immunoreactive Purkinje cells was observed in control pair - fed and alcohol+/-T4 group on and after P14. These cells of alcohol -fed group showed immature features. Single -layer arrangement of these cells in alcohol -fed group was not completely achieved throughout postnatal life. Electron microscopic observations of BDNF -immunoreactive Purkinje cells at P14 revealed large nucleus, small cytoplasm, small amount of ribosomal collection and rudimentary cytoplasmic organelles in alcohol -fed group. The morphology of BDNF -immunoreactive Purkinje cell in alcohol +/-T4 group was similar to that in control pair -fed group. It was characterized by numerous short segments of rough endoplasmic reticulum, many of which showed a tendency of parallel alignment that suggested an attempt at Nissl body configuration. The cytology of Golgi complexes was also found within the cytoplasm in perinuclear location. Those observed differences of postnatal maturation patterns between alcohol -fed and alcohol +/-T4 group may indicate the beneficial effects on the postnatal development of BDNF -containing Purkinje cells in cerebellar cortex in the pups of thyroxine -treated alcohol -exposed dams. These results suggest that the increase of BDNF synthesis during early postnatal life caused by maternal administration of exogenous thyroxine may ameliorate fetal alcohol effects as a result of the dysthyroid state following maternal alcohol abuse.

Postnatal Development of Brain Natriuretic Peptide-immunoreactive Neuron in the Hypothalamus of the Rat / 체질인류학회지

Brain natriuretic peptide (BNP) is a neuropeptide, isolated from porcine brain that is homologous with atriopeptin. Magnocellular neurosecretory cells located in the paraventricular nucleus and supraoptic nucleus synthesize and secrete neurohormones. The purpose of this study was to investigate distribution of BNP immunoreactivity throughout the rat hypothalamus from the day of birth to 30 days and adult using immunoperoxidase and immunofluorescent staining. The first BNP immunoreactive neurons appeared in the paraventricular and supraoptic nucleus at P10. In adult, BNP immunoreactivity was widely distributed throughout regions of the hypothalamus including dorsomedial hypothalamic nucleus, ventromedial hypothalamic nucleus, arcuate nucleus and internal layer of median eminence. The intensity of BNP immunoreactivity was weak in almost all hypothalamic nuclei except the paraventricular and supraoptic nuclei. BNP immunoreactivity was first observed in the lateral hypothalamic area at P15. In retrochiasmatic supraoptic nucleus, BNP immunoreactivity was first observed at P20 and remarkably distributed in adult. In the present study, distinct localization of BNP immunoreactivity was in the hypothalamic cell bodies and fibers. Although the role of BNP in the brain is yet to be determined, these results indicate that BNP in the neurons of hypothalamus play important role in the regulation of a variety of neurosecretory functions as a neuromodulator during postnatal development of the hypothalamus.

Postnatal Development of Brain Natriuretic Peptide-immunoreactive Neuron in the Hypothalamus of the Rat / 체질인류학회지

Brain natriuretic peptide (BNP) is a neuropeptide, isolated from porcine brain that is homologous with atriopeptin. Magnocellular neurosecretory cells located in the paraventricular nucleus and supraoptic nucleus synthesize and secrete neurohormones. The purpose of this study was to investigate distribution of BNP immunoreactivity throughout the rat hypothalamus from the day of birth to 30 days and adult using immunoperoxidase and immunofluorescent staining. The first BNP immunoreactive neurons appeared in the paraventricular and supraoptic nucleus at P10. In adult, BNP immunoreactivity was widely distributed throughout regions of the hypothalamus including dorsomedial hypothalamic nucleus, ventromedial hypothalamic nucleus, arcuate nucleus and internal layer of median eminence. The intensity of BNP immunoreactivity was weak in almost all hypothalamic nuclei except the paraventricular and supraoptic nuclei. BNP immunoreactivity was first observed in the lateral hypothalamic area at P15. In retrochiasmatic supraoptic nucleus, BNP immunoreactivity was first observed at P20 and remarkably distributed in adult. In the present study, distinct localization of BNP immunoreactivity was in the hypothalamic cell bodies and fibers. Although the role of BNP in the brain is yet to be determined, these results indicate that BNP in the neurons of hypothalamus play important role in the regulation of a variety of neurosecretory functions as a neuromodulator during postnatal development of the hypothalamus.

A Confocal Laser Scanning Microscopic Study on the Distribution and Fluorescent Intensity of NPY-IR in the Cerebral Cortex of the Head Irradiated Rats / 체질인류학회지

The purpose of this study, the effects on the cerebral cortex of the rats after brain irradiation was to investigate the change of distribution and morphology of neuropeptide-Y (NPY) neurons. Radiation was produced by the linear accelerator 6MV X-ray. The animals were categorized into control and experimental groups and we use 45 Sprague-Dawley rats weighing about 200 ~250 gm. The head areas of the animals were positioned within the radiation field of 15 cmx20 cm and with the radiation depth of 2 cm. Sodium chloral hydrate-anesthetized rats were exposed to the radiation with the dose rate of 240 cGy/min. The total dose was 1,800 cGy(rad). Animals were sacrificed on 2 hours, 5 hours, 1 day, 2 days, 3 days, 1 week, weeks, 3 weeks after brain irradiation. Using ABC immunohistochemistry, morphology and distribution of neuropeptide-Y immunoreactive neurons (NPY-IR)were studied on the cerebral cortex of the control and brain-irradiated rats. We used light and confocal laser scanning microscopy (CLSM). The following results were obtained : 1. On control group, NPY-IR neurons were found in all layers of the primary motor and sensory cerebral cortex, and the NPY-IR neurons were concentrated within the layer II, III, IV, V and VI. The typical NPY-IR perikarya was bipolar and multipolar shape. 2. On 2 hours, 5 hours after X-irradiation, decreased number of NPY-IR neurons were detected in the primary motor and sensory cerebral cortex of the rats. Also shrunken and transformed NPY-IR neurons were detected in the primary motor and sensory cerebral cortex of the rats. 3. On 1 day, 2 days, 3 days after X-irradiation, morphology and distribution of NPY-IR neurons in the primary motor and sensory cerebral cortex was generally restored. 4. On 1 week, 2 weeks, 3 weeks after X-irradiation, morphology and distribution of NPY-IR neurons in the primary motor and sensory cerebral cortex was almost similar to control group. 5. In optical serial section analysis of NPY-IR neurons, high intensity of immunofluorescence were observed in a part of the 8 ~11 sections of the control and all irradiated groups. In optical single section analysis of NPY-IR neurons, red color (high fluorescence intensity) were observed in a part of 6, 7 sections of the control and all irradiated groups. From the above results, it was concluded that the release of neurotransmitters and transcapillary leakage of blood substance were occurred on 2 hours, 5 hours, 1 day after X-irradiation, but the condition was generally restored on 3 days and 7 days following X-irradiation.

Morphological Studies on the Calbindin D-28K and Parvalbumin Immunoreactive Neurons in the Medulla Oblongata and Ventral Horn of the Spinal Cord Gray Matter after Spinal Cord Injury in Rats / 체질인류학회지

This study was examined and compared the immunocytochemical distribution of the two calcium-binding proteins calbindin D-28K and parvalbumin immunreactive neurons in the medulla oblongata and spinal cord after transection of spinal cord in rats. In this experiment, calbindin D-28K immnunoreactive neurons were mainly found in many pyramidal cells distributed medulla oblongata and spina1 cord of rats. Parvalbumin immunoreactive cells were demonstrated in all lamina of the gray matter of the spinal cord. These immunoreactive cells had the most high density in the severa1 nuclei of the ventra1 horn of the all segments of the spina1 cord. Calbindin D-28K neuropil labeling was strongly noted in spina1 all segments of the spinal cord. In contrast parva1bumin immunoreactive, little differences were found in distribution, size and morphology of calbindin D-28K cell body or neuropil staining in the spinal cord. The number of parvalbumin immunoreactive cells were more than twice in the medulla oblongata and spinal cord compared to the calbindin D-28K immunoreactive cells. Calbindin D-28K and parvalbumin-immmoreactive somata were round, ova1, spind1e and polygona1 in shape, and the immunoreactive neurons were unipolar, bipolar, multipolar and horizontal in shape. The diameters of the somata of the two immunoreactive neurons were 40 ~50 micrometer, respectively. Also dendrites of two immunoreactive neurons were densely arrayed in network. These results suggest that CB-IR and PV-IR most high density in the of the VII~X layers in the ventra1 horn of the all segments of the spina1 cord.

Functional Recovery in Complete Spinal Cord Injury after Transplantation of Human Umbilical Cord Blood Cells in Rats / 대한해부학회지

Many approaches have been adopted to restore function following spinal cord injury (SCI). These have included transplantation of fetal neurons, neuronal progenitor cells, or glial cells, or transplantation of transfected cells which produce a variety of substances. The use of human umbilical cord blood cells (hUCB cells) has recently been reported to alleviate behavioral consequences of stroke injury. We report here that hUCB cells delivered intravenously in rats with compression injury of the spinal cord increase the rate behavioral recovery. Tweny-five rats were divided into 5 groups (laminectomy only, laminectomy+hUCB cells, SCI+hUCB cells devlivered at one day post-injury, SCI+hUCBcells delivered at 5 days post-injury, and SCI only). SCI was produced by compressing the spinal cord for one minute with an aneurysm clip calibrated to a closing pressure of 50 gms. Rats were assessed behaviorally at one, two and three weeks using the BBB behavioral scale, inclined platform, and extension and toe spread tests. Following behavioral testing, spinal cords from these rats were examined immunohistochemically to identify hUCB cells. Spinal cords from SCI+hUCB cells animals contained hUCB cells in the area of SCI: No hUCBcells cells were found in noninjured areas of spinal cord from these animals or in animals in which only a laminectomy was performed. Rats in the SCI+hUCBcells 1 day group were significantly different in recovery of motor function as compared to the SCI+hUCB cells 5 day group and laminectomy groups. By three weeks, SCI+hUCB cells animals were not significantly different from each other. These results indicate that hUCBcells cells may be beneficial in reversing the behavioral effects of SCI.

Postnatal Development of Transforming Growth factor-alpha-immunoreactive Neurons in the Diencephalon of the Rat / 체질인류학회지

Transforming growth factor-alpha (TGF-alpha) immunoreactivity during postnatal development was examined in the rat diencephalon using immunohistochemistry. The time of appearance and localization of TGF-alpha immunoreactivity was slightly different in many areas of diencephalon during postnatal development. At birth, TGF-alpha immunoreactivity was mainly evident in thalamic medial, median and parafascicular thalamic nucleus of intralaminar nuclei. In addition, TGF-alpha immunoreactivity was clearly evident at the first postnatal week in most hypothalamic nuclei. Therefore, TGF-alpha immunoreactivity was found at postnatal days 7 in most diencephalic nuclei excepting the vental posterior thalamic nuclei, metathalamus and epithalamus. The quantitative increase of number was first apparent in the midline structures of thalamus in the first postnatal week. And then TGF-alpha-immunoreactive cells progressively increased throughout diendephalon by postnatal days 15. Adult patterns were reached at postnatal days 20. These results indicate that TGF-alpha-immunoreactive cells were first appeared in thalamic midline structures, increased progressively in the first two postnatal weeks, and followed mediolateral gradient. In addition to maturation of TGF-alpha-immunoreactive cells requires a relatively prolonged period of time to achieve an adult configuration. Also, the early appearance of TGF-alpha immunoreactivity in most diencephalic nuclei may be related to the early appearance of EGFR immunorecativity in many other brain regions. Taken together, these findings suggest that TGF-alpha immunoreactivity correlated with the appearance of the related functional activity in the different regions of diencephalon.

Postnatal Development of Transforming-growth Factor-alpha and Epidermal Growth Factor Receptor-immunoreactive Neurons in the Cerebral Cortex of the Rat / 대한해부학회지

Transforming growth factor-alpha (TGF-alpha ) and epidermal growth factor receptor (EGFR) immunoreactivities were examined in the cerebral cortex of the rat during postnatal development. TGF-alpha -immunoreactive cells were found at birth in all cortical layers except the molecular layer. TGF-alpha -immunoreactive cells were most abundant in the parietal cortex at P20. The intensity and number of the TGF-alpha -immunoreactive cells increased at postnatal days 15 or 20 (P15 - P20). Mature patterns of TGF-alpha -immunoreactive cells were achieved at P20. EGFR -immunoreactive cells appeared only in dorsal endopiriform cortex at P0. The first EGFR -immunoreactive cells were observed in the neocortex at P3. These cells were most abundant in the parietal cortex at P90. In adult, the most prominent EGFR immunoreactivity occured in layer IV, V and VI. These cells were numerous in the frontal and parietal cortex, diminishing laterally towards the insular cortex. Adult patterns were reached on and after P10. The time of appearance and localization of EGFR immunoreactivity correlated with functional activity in the different cortical areas. No clear labelling of glial cells with TGF-alpha and EGFR antibodies was found. TGF -alpha and EGFR immunoreactivity was observed in the majority of neurons in the postnatal developing and adult cerebral cortex of the rat. Also double -immunohistochemistry with antibodies to TGF-alpha and EGFR showed co-localization of TGF -alpha and EGFR in neurons of the cerebral cortex. Co-localization of TGF-alpha and EGFR was first detectable in most cortices at P3. By P10, these neurons showed immature neuronal features. The present results showing TGF -alpha and EGFR immunoreactivity is widely distributed in the postnatal developing (except P0) and adult cerebral cortex, mainly localized in neurons. And TGF-alpha and EGFR co-localize in most neurons, thus indicating that most EGFR -containing cells are TGF-alpha -synthesizing cells. In addition to difference of time of appearance and mature neuronal pattern suggest that TGF-alpha has the capacity of activating the EGFR in the normal postnatal developing cerebral cortex, therefore, TGF-alpha and EGFR may interact within cortical neurons through many different mechanism according to postnatal age.

Immunohistochemical Study on Parvalbumin and Calbindin D-28k Immunoreactive Neurons in the Dog Olfactory Bulb / 대한해부학회지

We have studied the distribution of calcium-binding proteins parvalbumin (PV -IR) and calbindin D-28k (CB -IR) immunoacitivity in the mongrel dog olfactory bulb using monoclonal antibodies and the avidin -biotin -immunoperoxidase method. The possible coexistence of both markers was determined by segmental histochemical and immunohistochemical double labelling of the same section. In the olfactory bulb of mongrel dog, PV-IR and CB-IR were mainly located in the external plexiform layer, and a few scattered in the glomerular layer, mitral cell layer, and glanule cell layer in the order of thier existence. In addition, three neuronal types were observed in the glomerular layer and external plexiform layer border. Horizontal cells and vertical cells of Cajal were also observed after both PV-IR and CB-IR labeling. Distict groups of PV-IR and CB-IR, differing in size, shape, dendritic branching pattern, and staining intensity, were distinguished in the all layers of the olfactory bulb. Specific neuronal populations were positive for both PV-IR and CB-IR markes. No cell colocalized both stains in the mongrel dog olfactory bulb. The number of PV-IR were more than abundant in olfactory bulb compared to the CB-IR cells. The PV-IR and CB-IR postitive cell somata were round, oval, spindle and polygonal in shape, and they were unipolar, bipolar and multipolar in type. The diameters of the somata of the PV-IR and CB-IR neurons were 20~40 micro meter, respectively. Also dendrites of the these neurons were densely arrayed in arborization.

Postnatal Development of Epidermal Growth Factor Receptor: Immunoreactivity in the Cerebral Cortex of the Rat / 대한해부학회지

Epidermal growth factor receptor (EGFR), a 170-kDa transmembrane glycoprotein, appears to mediate epidermal growth factor (EGF) activity. Transforming growth factor-alpha and EGF produce their biological effects in numerous systems by stimulating the EGFR. In the present study, we examine the postnatal development of EGFR immunoreactivity in the different regions of the neocortex of the rat. EGFR immunoreactivity in the neocortex of the rat followed very different patterns according to postnatal ages and cortical areas. EGFR-immunoreactive cells appeared only in dorsal endopiriform cortex at P0. The first EGFR-immunoreactive cells were observed in the neocortex at P3. In the cingulate cortex, the first EGFR-immunoreactive cells appeared at P10. Also, in the retrosplenial cortex, these cells appeared in the agranular region at P3, and in the granular region at P20. These cells were most abundant in the parietal cortex at P90. In adult, the most prominent EGFR immunoreactivity occured in layer IV, V and VI. These cells were numerous in the frontal and parietal cortex, diminishing laterally towards the insular cortex. The intensity of the immunoreaction at P10 was similar to their adult pattern, but their morphologies were exhibited immature features. EGFR immunoreactivity was not found in the glial cells. The present results showing EGFR immunoreactivity is widely distributed in the postnatal developing (except P0) and adult cerebral cortex, mainly localized in neurons. These findings suggest that many growth factors may interact via the EGFR, therefore, actions to promote the proliferation and survival of neurons in the normal postnatal developing neocortex of the rat.

Postnatal Development of Parvalbumin and Calbindin D-28k Immunoreactivities in the Canine Anterior Cingulate Cortex: Transient Expression in Layer V Pyramidal Cells / 대한해부학회지

We have examined the ontogeny of parvalbumin and calbindin D-28k immunoreactivities in the canine anterior cingulate cortex from the day of birth (P0) through P180. At P7, parvalbumin immunoreactivity appears firstly in layer VI multipolar cells. The parvalbumin immunoreactivity in GABAergic interneurons appears to follow an 'inside-out' gradient of radial mergence and reaches an adult-like pattern by the end of the 6th postnatal month. Immunoreactivity is limited mainly to developing nonpyramidal cells, whereas pyramid-like parvalbumin immunoreactive cells are transiently observed in layer V from the P14 to the P90. The developmental pattern of calbindin D-28k immunoreactivity differs from that of parvalbumin immunoreactivity. Calbindin D-28k immunoreactivity develops firstly in layer V pyramidal cells from P0, which continues through the third postnatal month. Calbindin D-28k immunoreactive interneurons are located in the infragranular layers and white matter at P0 and increase in both the supragranular and infragranular layers by P14. This is followed by an adult-like pattern at the P180. These data suggested that parvalbumin and calbindin D-28k may play a role in protecting immature neurons from intracelluar calcium influx during postnatal development.

Immunohistochemical Studies on the Calbindin D -28K and Parvalbumin Positive Neurons in the Brain Stem and Spinal Cord after Transection of Spinal Cord of Rats / 체질인류학회지

This studies were examined and compared the immunohistochemical distribution of the two calcium -binding proteins calbindin D -28K and parvalbumin positive neurons in the brain stem and spinal cord after transection of spinal cord in rats. In this experiment, calbindin D -28K immunoreactive neurons were mainly found in many pyramidal cells distributed in the brain stem and spinal cord of rats. Calbindin D -28K neuropil labeling was strongly noted in brain stem and in spinal all segments of the spinal cord. In contrast to parvalbumin, little differences were found in distribution, size and morphology of calbindin D -28K cell body or neuropil staining in the brain stem and spinal cord. Parvalbumin immunoreactive cells were demonstrated in all lamina of the gray matter of the spinal cord. These immunoreactive cells had the most high density in the layer I and II dorsal horn and several nuclei of the ventral horn of the all segments of the spinal cord. These immunoreactive cells between the brain stem and spinal cord were quite different markedly in number, cell size and morphology The number of parvalbumin positive cells were more than twice in the brain stem and spinal cord compared to the calbindin D -28K positive cells. Calbindin D -28K and parvalbumin -immunoreactive somata were round, oval, spindle and polygonal in shape, and the positive neurons were unipolar, bipolar, multipolar and horizontal in shape. The diameters of the somata of the two positive neurons were 30 ~40 micrometer, respectively. Also dendrites of two positive neurons were densely arrayed in arborization.

Immunohistochemical Study on Platelet-Derived Growth Factor alpha-Receptor (PDGF-alphaR) in the Canine Cerebellum During Postnatal Development / 대한해부학회지

The biological activities of PDGF include stimulation of mitogenesis, chemotaxis, and differentiation. In nervous system, previous studies have shown that PDGF has an important role in the generation of cells of a glial lineage. However, several studies demonstrated that mature and immature neurons could also synthesize PDGF-alphaR. In the present study, to analyze the distributional pattern of PDGF-alphaR during postnatal development of the canine cerebellum, we used immunohistochemistry. We found that neurons of cerebellum, including Purkinje cells and granules cells, showed immunoreactivity to PDGF-alphaR (IRPDGF-alphaR) as early as postnatal day 0. Whereas IRPDGF-alphaR immunoreactivity in the Purkinje cells were maintained at all postnatal ages. Our data support that PDGF may have the important roles during development and survival of neurons.