• Title/Summary/Keyword: olfactory bulb

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Distribution of the neuropeptide Y immunoreactive neurons in the olfactory bulb of striped field mouse(Apodemus agrarius) (야생등줄쥐(Apodemus agrarius) 후각망울의 neuropeptide Y 면역반응세포의 분포)

  • Jeong, Young-gil;Kim, Kil-soo;Jung, Ju-young;Lee, Nam-seob;Lee, Kyeng-youl;Kim, Moo-kang
    • Korean Journal of Veterinary Research
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    • v.39 no.3
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    • pp.407-416
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    • 1999
  • This study was carried out to investigate the NPY-immunohistochemical characteristics of the olfactory bulb in the striped field mouse(Apodemus agrarius). The animals were anesthesized with thiopental sodium and perfused with 4% paraformaldehyde through left ventricle and aorta. Brains were removed and tranfered 10%, 20% and 30% sucrose. Sections were then cut on a cryostat into $40{\mu}m$-thick. The tissue immunostained with avidin-biotinylated complex method. The main olfactory bulb consisted of seven circumferential laminae : an olfactory nerve fiber layer, a glomerular layer with glomeruli surrounding by periglomerular cells, an external plexiform layer having granule and tufted cells, a mitral cell layer, a narrow internal plexiform layer, a granule cell layer forming several cell rows and a layer of white matter. The accessory olfactory bulb had four layers : an olfactory or vomeronasal nerve fiber layer, a glomerular layer consisting of small glomeruli, a mixed layer not distinguishing the external plexiform/mitral cell/granule cell layers and a granule cell layer. Most of NPY-immunoreactive(NPY-IR) neurons in main olfactory bulb were localized in the deeper portion of granule cell layer, white matter and anterior olfactory nucleus. In addition, some NPY-IR neurons were identified in the external plexiform layer. The shape of NPY-IR neurons of all olfactory bulb were predominant round or oval, sometime multipolar in shape. And most NPY-IR processes were parallel to long axis of white matter. In accessory olfactory bulb, NPY-IR neurons were not found in all region.

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Tyrosine hydroxylase immunoreactive neurons of the olfactory bulb in the stripped field mouse(apodemus agrarius coreae) (야생등줄쥐 후각망울의 Tyrosine hydroxylase 면역반응신경세포)

  • Jeong, Young-gil;Lee, Nam-seob;Kim, Kil-soo;Lee, Chul-ho;Hyun, Byung-hwa;Won, Moo-ho;Kim, Moo-kang
    • Korean Journal of Veterinary Research
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    • v.37 no.3
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    • pp.499-508
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    • 1997
  • The distributions and morphological characteristics of neurons displaying immunoreactivity to the catecholamine synthetic enzymes, tyrosine hydroxylase(TH), dopamine-${\beta}$-hydroxylase(DBH), and phenylethanolamine-N-methyltransferase (PNMT) were examined in the adjacent sections of the olfactory bulb of the Striped Field Mouse(Apodemus agrarius coreae). None of these cell groups displayed either DBH or PNMT immunoreactivity. Many TH-immunoreactive neurons were present in the olfactory bulb. The vast majority of such cells occurred in the glomerular layer as periglomerular cells surrounding the glomeruli. Numerous addtional cells were present in the external plexiform layer, and scattered in the mitral cell layer and internal plexiform layer. Also TH-immunoreactive neurons were found in the glomerular layer and granular layer of the accessory olfactory bulb.

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The Distribution of TrkA in the Olfactory Bulb and Basal Nucleus of the Mongolian Gerbil after Birth (출생 후 몽골리안 저빌의 후각망울과 기저핵에서 TrkA의 분포)

  • Hou, Xilin;Park, Il-kwon;Lee, Kyung-youl;Park, Mi-sun;Kim, Sang-keun;Lee, Kang-yi;Lee, Geun-jwa;Kim, Moo-kang
    • Korean Journal of Veterinary Research
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    • v.43 no.3
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    • pp.317-322
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    • 2003
  • TrkA is an essential component of the high affinity NGF receptor necessary to the mediate biological effects of the neurotrophins NGF. Here we report on the expression of TrkA in the olfactory bulb and basal nucleus of Mongolian gerbil brain during the postnatal development. The expressions of TrkA were identified in a immunohistochemical method. Higher levels of TrkA immunoreactivity were detected in septum than that in olfactory bulb and caudate putamen (CPu). But TrkA was not observed before postnatal days (PND6) in olfactory bulb and PND9 in CPu. No TrkA-positive cell was detectable in the olfactory fiber layer. Several regions, such as olfactory bulb and CPu, showed weak labeling. These data show that expression of TrkA is developmentally regulated during postnatal Mongolian gerbil brain development and suggest that high affinity neurotrophinreceptors mediate a transient response to neurotrophins in many regions during the brain ontogeny.

Altered expression of parvalbumin immunoreactivity in rat main olfactory bulb following pilocarpine-induced status epilepticus

  • Yu, Yeon Hee;Park, Dae-Kyoon;Yoo, Dae Young;Kim, Duk-Soo
    • BMB Reports
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    • v.53 no.4
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    • pp.234-239
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    • 2020
  • Epilepsy is a chronic neurological disease characterized by spontaneous recurrent seizures and caused by various factors and mechanisms. Malfunction of the olfactory bulb is frequently observed in patients with epilepsy. However, the morphological changes in the olfactory bulb during epilepsy-induced neuropathology have not been elucidated. Therefore, in the present study, we investigated the expression of parvalbumin (PV), one of the calcium-binding proteins, and morphological changes in the rat main olfactory bulb (MOB) following pilo-carpine-induced status epilepticus (SE). Pilocarpine-induced SE resulted in neuronal degeneration in the external plexiform layer (EPL) and glomerular layer (GL) of the MOB. PV immunoreactivity was observed in the neuronal somas and processes in the EPL and GL of the control group. However, six hours after pilocarpine administration, PV expression was remarkably decreased in the neuronal processes compared to the somas and the average number of PV-positive interneurons was significantly decreased. Three months after pilocarpine treatment, the number of PV-positive interneurons was also significantly decreased compared to the 6 hour group in both layers. In addition, the number of NeuN-positive neurons was also significantly decreased in the EPL and GL following pilocarpine treatment. In double immunofluorescence staining for PV and MAP2, the immunoreactivity for MAP2 around the PV-positive neurons was significantly decreased three months after pilocarpine treatment. Therefore, the present findings suggest that decreases in PV-positive GABAergic interneurons and dendritic density in the MOB induced impaired calcium buffering and reciprocal synaptic transmission. Thus, these alterations may be considered key factors aggravating olfactory function in patients with epilepsy.

Distinct Developmental Features of Olfactory Bulb Interneurons

  • Kim, Jae Yeon;Choe, Jiyun;Moon, Cheil
    • Molecules and Cells
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    • v.43 no.3
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    • pp.215-221
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    • 2020
  • The olfactory bulb (OB) has an extremely higher proportion of interneurons innervating excitatory neurons than other brain regions, which is evolutionally conserved across species. Despite the abundance of OB interneurons, little is known about the diversification and physiological functions of OB interneurons compared to cortical interneurons. In this review, an overview of the general developmental process of interneurons from the angles of the spatial and temporal specifications was presented. Then, the distinct features shown exclusively in OB interneurons development and molecular machinery recently identified were discussed. Finally, we proposed an evolutionary meaning for the diversity of OB interneurons.

Differential Expression of NCAM-180 in the Olfactory System and Retina of the Rat

  • Hyeyoung Koo
    • Animal cells and systems
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    • v.3 no.3
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    • pp.259-267
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    • 1999
  • The expression of the neural cell adhesion molecule-180 (NCAM-180), which accumulates at contact sites between cells and may be responsible for the stabilization of cell contacts, was studied in the olfactory system and retina of developing and adult rats. From embryonic day 12 onwards, which was the earliest stage examined, the NCAM-180 pathway directing to the presumptive olfactory bulb was observed. In later stages, olfactory neurons and fasciculating axons in the olfactory epithelium and nerve fiber layer and glomeruli of the olfactory bulb expressed NCAM-180. From postnatal day 0, immunolabelling pattern of the olfactory epithelium and olfactory bulb were the same as that during later stages. NCAM-180 immunoreactivity was present on differentiating retinal cells and persisted on those cells throughout adulthood. However, contrary to the olfactory nerve which remained detectable in the adult, the optic nerve was only transiently expressed with NCAM-180 and was no longer detectable in the adult. The presence of NCAM-180 in olfactory tissues suggests their possible role in pathfinding, differentiation, fasciculation and synaptic plasticity. The continued presence of NCAM-180 in the olfactory system examined may underlie its continuous cell turnover and regenerative capacity. The continuous expression of NCAM-180 in ganglion cells, bipolar cells and photoreceptor cells, also suggests potential regenerating capability and some plastic functions for these cells in the adult. Since the expression of NCAM-180 by the optic nerve was restricted to the period of special histogenetic events, for example, during axonal growth and synaptogenesis, it is possible that the lack of NCAM-180 in the adult optic nerve might cause a nonpermissive environment for the regeneration and result in regenerative failure of this system.

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Expression of Kir2.1 Channels in Astrocytes Under Pathophysiological Conditions

  • Kang, Shin Jung;Cho, Sang-hee;Park, Kyungjoon;Yi, Jihyun;Yoo, Soon Ji;Shin, Ki Soon
    • Molecules and Cells
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    • v.25 no.1
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    • pp.124-130
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    • 2008
  • Astrocyte ion channels participate in ionic homeostasis in the brain. Inward rectifying potassium channels (Kir channels) in astrocytes have been particularly implicated in $K^+$ homeostasis because of their high open probability at resting potential and their increased conductance at high concentrations of extracellular $K^+$. We examined the expression of the Kir2.1 subunit, one of the Kir channel subunits, in the mouse brain by immunohistochemistry. Kir2.1 channels were widely distributed throughout the brain, with high expression in the olfactory bulb and the cerebellum. Interestingly, they were abundantly expressed in astrocytes of the olfactory bulb, while astrocytes in other brain regions including the hippocampus did not show any detectable expression. However, Kir2.1 channel-expressing cells were dramatically increased in the hippocampus by kainic acid-induced seizure and the cells were glial fibrillary acidic protein (GFAP)-positive, which confirms that astrocytes in the hippocampus express Kir2.1 channels under pathological conditions. Our results imply that Kir2.1 channels in astrocyte may be involved in buffering $K^+$ against accumulated extracellular $K^+$ caused by neuronal hyperexcitability under phathophysiological conditions.

Radiological Diagnosis for Posttraumatic Olfactory Dysfunction (외상 후 후각이상에 대한 방사선학적 진단)

  • Ahn, Jung Yong;Joo, Jin Yang;Chung, Tae Sub
    • Journal of Korean Neurosurgical Society
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    • v.29 no.12
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    • pp.1570-1576
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    • 2000
  • Objective : To evaluate objectively the sites of injury in patients with posttraumatic olfactory deficits and to suggest the diagnostic procedure for evaluation of posttraumatic anosmia. Methods : Ten patients with posttraumatic olfactory dysfunction were examined by means of olfactory testing, sinoscopy, contrast filled paranasal sinus computed tomography(contrast filled PNS CT) and magnetic resonance imaging(MRI). Five normal persons without olfactory dysfunction were also evauluated. The aerodynamic patency of olfactory cleft was examined by contrast filled PNS CT. The olfactory system(oflactory bulbs, olfactory tracts, inferior frontal region, hippocampi, or temporal lobes) was investigated in detail with MRI. The difference in the size of the olfactory bulb between normal volunteers and anosmic patients was evaluated by Student's t test. Results : Contrast filled dynamic CT scan was useful method for the evaluation of dynamic patency of the olfactory cleft. Paranasal CT scan of the all anosmic patients showed dynamic reflux of contrast media in olfactory cleft on valsalva maneuver. For the largest cross-sectional area and great height, the difference in olfactory bulb size between normal volunteers and patients was statistically significant(p<0.001) in MRI study. Conclusion : Posttraumatic anosmia was completely evaluated by olfactory testing, sinoscopy, and contrast filled CT scan for differentiation between conductive type and neurogenic type. Neurogenic anosmia was confirmed by perfect localization with MRI study.

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Effects of Olfactory Bulbectomy on Catalepsy Induced by Haloperidol in Rats (흰쥐에서 할로페리돌에 의해서 유발된 강경증에 미치는 후구 적출의 영향)

  • Chun, Seoung-Ho;Kim, Seon-Jang;Bae, Ki-Hwan;Lee, Soon-Chul
    • YAKHAK HOEJI
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    • v.36 no.5
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    • pp.427-432
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    • 1992
  • We attempted to clarify the effect of bilateral olfactory bulbectomy on catalepsy induced by haloperidol in rats. The incidence of catalepsy induced by haloperidol remarkably increased after lesion of olfactory bulb, which was significantly inhibited by L-5-hydroxytryptophan, L-DOPA, and ginseng's total saponin but reserpine and ${\alpha}-methyl-p-tyrosine$ were ineffective. The dopamine content of brain was significantly decreased by olfactory bulbectomy, but this result was reversed by ginseng's total saponin.

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Ultrastructural Pattern of Synapses in the Rat Olfactory Bulb during Postnatal Development (성장기 흰쥐의 후각망울에서 신경연접의 구조적 변동)

  • Rho, Sook-Young;Lee, Hee-Lai
    • Applied Microscopy
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    • v.24 no.4
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    • pp.32-40
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    • 1994
  • This study was undertaken to study the morphological changes of rat synapses during early postnatal periods. Neonatal rats were grouped by 1st, 2nd, 3rd, 4th and 6th postnatal weeks, and we observed the ultrastructural pattern of the synapses in the external plexiform layer of olfactory bulbs by electron microscopy. The results were as follows; 1. The numbers of synapses, lengths of synaptic thickenings and amounts of synaptic vesicles were markedly increased in the external plexiform layer during four postnatal weeks. 2. There was a tendency of increasing the proportion of the asymmetric synapse and the curved synapses during maturation. From the above results, it is suggested that the size of synapse is increasing during maturation, and at the same time the asymmetric synapses are formed from the symmetric type and the curved synapses are from the plane type.

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