• Title/Summary/Keyword: Functional neuron

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Regulation of SPIN90 by Cell Adhesion and ERK Activation

  • Kim Sung Hyun;Kim Dae Joong;Song Woo Keun
    • Proceedings of the Microbiological Society of Korea Conference
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    • 2004.05a
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    • pp.141-146
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    • 2004
  • SPIN90 was identified to farm molecular complex with $\betaPIX$, WASP and Nck. This complex shows that SPIN90 interacts with Nck in a manner dependent upon cell adhesion to extracellular matrix, but $SPIN90{\cdot}{\beta}PIX{\cdot}WASP$ complex was stable even in suspended cells. This suggests that SPIN90 serves as an adaptor molecule to recruit other proteins to Nck at focal adhesions. SPIN90 was phosphorylated by ERK1, which was, itself, activated by cell adhesion and platelet-derived growth factor. Such phosphorylation of SPIN90 likely promotes the interaction of the $SPIN90{\cdot}{\beta}PIX{\cdot}WASP$ complex and Nck. It thus appears that the interaction of the $SPIN90{\cdot}{\beta}PIX{\cdot}WASP$ complex with Nck is crucial for stable cell adhesion and can be dynamically modulated by SPIN90 phosphorylation that is dependent on cell adhesion and ERX activation. SPIN90 directly binds syndapin I, syndapin isoform II-1 and II-s via its PRD region in vitro, in vivo and also associates with endocytosis core components such as clathrin and dynamin. In neuron and fibroblast, SPIN90 colocalizes with syndapins as puntate form, consistent with a role for SPIN90 in clathrin-mediated endocytosis pathway. Overexpression of SPIN90 N-term inhibits receptor-mediated endocytosis. Interestingly, SPIN90 PRD, binding interface of syndapin, significantly blocks internalization of transferrin, demonstrating SPIN90 involvement in endocytosis in vivo by interacting syndapin. Depletion of endogenous SPIN90 by introducing $\alpha-SPIN90$ also blocks receptor-mediated endocytosis. Actin polymerization could generate farce facilitating the pinch-out event in endocytosis, detach newly formed endocytic vesicle from the plasma membrane or push out them via the cytosol on actin tails. Here we found that SPIN90 localizes to high actin turn over cortical area, actin-membrane interface and membrane ruffle in PDGF treated cells. Overexpression of SPIN90 has an effect on cortical actin rearrangement as filopodia induction and it is mediated by the Arp2/3 complex at cell periphery. Consistent with a role in actin organization, CFP-SPIN90 present in actin comet tail generated by PIP5 $kinase\gamma$ overexpression. Therefore this study suggests that SPIN90 is functional linker between endocytosis and actin cytoskeleton.

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The Changes of Cyclic AMP Content by Opiates in Chronic Haloperidol Treated Mouse Striatum (Haloperidol 장기 투여된 Mouse Striatum에서 cAMP양에 미치는 Opiates의 영향)

  • Kim, Soo-Kyung
    • The Korean Journal of Pharmacology
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    • v.30 no.1
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    • pp.11-18
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    • 1994
  • Cyclic adenosine 3'5'-monophosphate (cyclic AMP) has been frequently accepted as an intracellular messenger for receptor-mediated action of opioids. In this experiment, it was designed to determine the interaction of dopaminergic and opioidergic system in the mouse striatum in normal and chronic haloperidol treated groups. Haloperidol 750ug/kg I.P. for 10 days was performed for dopamine denervation. The morphine, DAGO, DPDPE, and U5O,488H inhibited the increase of haloperidol-induced cyclic AMP content in chronic haloperidol treated mouse striatum. The inhibition of DAGO and DPDPE showed significant increase compared to normal mouse striatum. Naloxone showed antagonistic effect on the morphine and U5O,488H in chronic haloperidol treated group, and showed antagonistic effect on morphine, DAGO, DPDPE, and U5O, 488H in normal mouse striatum. These findings support that there is a functional interrelationship of dopaminergic and opioidergic pathway in the striatum. This result provides an evidence that following destruction of striatal dopaminergic neuron, there are some changes of cAMP content on the ${\mu},\;{\gamma},\;and\;{\kappa}$ opioid receptor, but the ${\kappa}$ opioid receptor still has its function.

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Clinical Observation on a Case of Patient with Amyotrophic Lateral Sclerosis (근위축성 측삭 경화증 환자 치험 1례)

  • Choi, Eun-Hee;Jeon, Ju-Hyun;Kim, Yeon-Mi;Lee, Jae-Min;Go, Seung-Kyoung;Kang, Min-Wan;Kim, Sung-Lae;Yang, Gi-Young;Kim, Young-Il;Lee, Hyun
    • Journal of Acupuncture Research
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    • v.24 no.4
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    • pp.225-235
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    • 2007
  • Amyotrophic Lateral Sclerosis(ALS) is Motor Neuron Disease(MND) that reveals muscle relaxation, bulbar palsy, extremities weakness, Pneumonia, in severe case, leads to death. Objectives : Amyotrophic Lateral Sclerosis is one of the incurable disease. In Oriental medicine, Wei symptom is similar as Amyotrophic Lateral Sclerosis, so we diagnosed it as Wei symptom and treated in Oriental medical system. Methods : The patient was treated by acupunture, moxibustion, herb medication, physical treatment. The improvement of the patient was judged by Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS), Grasping power on right arm, circumference of thigh and calf. Result : The patient had better condition for a while but the sputum irritated breathing and the day before he discharged vital sign was not stable and could not breath well. Conclusion : It is necessary to have more examination about the incurable syndromes such as Amyotrophic Lateral Sclerosis, and keep the patient's life better and expand their lives.

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A Comparative Study of Gene Expression Patterns of Periodontal Ligament Cells and Gingival Fibroblasts using the cDNA Microarray (cDNA Microarray를 이용한 치주인대세포와 치은섬유아세포의 유전자 발현에 대한 연구)

  • Jeon, Chai-Young;Park, Jin-Woo;Lee, Jae-Mok;Suh, Jo-Young
    • Journal of Periodontal and Implant Science
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    • v.34 no.1
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    • pp.205-221
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    • 2004
  • Periodontal ligament(PDL) cells have been known as playing an important roles in periodontal regeneration and gingival fibroblasts are also important to periodontal regeneration by forming connective tissue attachment. There were rare studies about the gene expression patterns of PDL cells and gingival fibroblasts, therefore in this study, we tried cDNA microarray-based gene expression monitoring to explain the functional differences of PDL cells and gingival fibroblasts in vivo and to confirm the characteristics of PDL cells. Total RNA were extracted from PDL cells and gingival fibroblasts of same person and same passages, and mRNA were isolated from the total RNA using Oligotex mRNA midi kit(Qiagen) and then fluorescent cDNA probe were prepared. And microarray hybridization were performed. The gene expression patterns of PDL cells and gingival fibroblasts were quite different. About 400 genes were expressed more highly in the PDL cells than gingival fibroblasts and about 300 genes were more highly expressed in the gingival fibroblasts than PDL cells. Compared growth factor- and growth factor receptor-related gene expression patterns of PDL cells with gingival fibroblasts, IGF-2, IGF-2 associated protein, nerve growth factor, placental bone morphogenic protein, neuron-specific growth- associated protein, FGF receptor, EGF receptor-related gene and PDGF receptor were more highly expressed in the PDL cells than gingival fibroblasts. The results of collagen gene expression patterns showed that collagen type I, type III, type VI and type VII were more highly expressed in the PDL cells than gingival fibroblasts, and in the gingival fibroblasts collagen type V, XII were more highly expressed than PDL cells. The results of osteoblast-related gene expression patterns showed that osteoblast specific cysteine-rich protein were more highly expressed in the PDL cells than gingival fibroblasts. The results of cytoskeletal proteins gene expression patterns showed that a-smooth muscle actin, actin binding protein, smooth muscle myosin heavy chain homolog and myosin light chain were more highly expressed in the PDL cells than gingival fibrobalsts, and ${\beta}-actin$, actin-capping protein(${\beta}$ subunit), actin- related protein Arp3(ARP) and myosin class I(myh-1c) were more highly expressed in the gingival fibroblasts than PDL cells. Osteoprotegerin/osteoclastogenesis inhibitory factor(OPG/OCIF) was more highly expressed in the PDL cells than gingival fibroblasts. According to the results of this study, PDL cells and gingival fibroblasts were quite different gene expression patterns though they are the fibroblast which have similar shape. Therefore PDL cells & gingival fibroblasts are heterogeneous populations which represent distinct characteristics. If more studies about genes that were differently expressed in each PDL cells & gingival fibroblasts would be performed in the future, it would be expected that the characteristics of PDL cells would be more clear.

Influence of Melatonin on Reproductive Function in Male Golden Hamsters (수컷 골든 햄스터의 생식기능에 미치는 멜라토닌의 영향)

  • Choi, Don-Chan
    • Development and Reproduction
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    • v.5 no.1
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    • pp.1-8
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    • 2001
  • Golden hamsters show the reproductive activity that is determined by the photoperiod (length of light per day). Photoperiod is an environmental factor that is predictable through an entire year. The hamsters are sexually active in summer during which day length exceeds night time. The critical length is at least 12.5 hours of light in a day where reproductive function is maintained. The information of photoperiod is mediated by the pineal gland because removal of pineal gland blocks the influence of photoperiod on reproductive activity. The hamsters without pineal gland maintain sexual activity and promote it in a situation that suppresses gonadal activity. The pineal gland secretes melatonin that reflects the photoperiod. The appropriate administrations of melatonin into both pineal intact and pinealectomized hamsters lead to a gonadal reression. The results suggest that melatonin constitutes a part of control mechanism whereby environmental information is transduced to neuroendocrine signal respensible for the functional integrity of the reproductive system. Despite of the intense studies, the action site of melatonin is on the whole unknown. It is mainly due to the lack of acute efffct of melatonin on the secretion of reproductive hormones. However, sexually regressed animals display the low levelsof gonadotropins and the augmentation of the hypothalamic gonadotropin-releasing hormone (GnRH) content, implying that the antigonadotropic effects either by photoperiod and/or by the treatment of melatonin are mediated by the GnRH neuronal system. The action mechanism by which melatonin exerts its effect on GnRH neuron needs to be investigated. Recent cloning of melatonin receptor will contribute to examine various and putative potencies of melatonin via its anatomical identification and the action mechanism of melatonin on target tissues at the molecular level.

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Advanced Onset of Puberty in High-Fat Diet-Fed Immature Female Rats - Activation of KiSS-1 and GnRH Expression in the Hypothalamus -

  • Lee, Song-Yi;Jang, Yeon-Seok;Lee, Yong-Hyun;Seo, Hyang-Hee;Noh, Kum-Hee;Lee, Sung-Ho
    • Development and Reproduction
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    • v.13 no.3
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    • pp.183-190
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    • 2009
  • In mammals, puberty is a dynamic transition process from infertile immature state to fertile adult state. The neuroendocrine aspect of puberty is started with functional activation of hypothalamus-pituitary-gonadal hormone axis. The timing of puberty can be altered by many factors including hormones and/or hormone-like materials, social cues and metabolic signals. For a long time, attainment of a particular body weight or percentage of body fat has been thought as crucial determinant of puberty onset. However, the precise effect of high-fat (HF) diet on the regulation of hypothalamic GnRH neuron during prepubertal period has not been fully elucidated yet. The present study was undertaken to test the effect of a HF diet on the puberty onset and hypothalamic gene expressions in immature female rats. The HF diet (45% energy from fat, HF group) was applied to female rats from weaning to around puberty onset (postnatal days, PND 22-40). Body weight and vaginal opening (VO) were checked daily during the entire feeding period. In the second experiment, all animals were sacrificed on PND 36 to measure the weights of reproductive tissues. Histological studies were performed to assess the effect of HF diet feeding on the structural alterations in the reproductive tissues. To determine the transcriptional changes of reproductive hormone-related genes in hypothalamus, total RNAs were extracted and applied to the semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). Body weights of HF group animals tend to be higher than those of control animals between PND 22 and PND 31, and significant differences were observed PND 32, PND 34, PND 35 and PND 36 (p<0.05). Advanced VO was shown in the HF group (PND $32.8{\pm}0.37$ p<0.001) compared to the control (PND $38.25{\pm}0.25$). The weight of ovaries (p<0.01) and uteri (p<0.05) from HF group animals significantly increased when compared to those from control animals. Corpora lutea were observed in the ovaries from the HF group animals but not in control ovaries. Similarly, hypertrophy of luminal and glandular uterine epithelia was found only in the HF group animals. In the semi-quantitative RT-PCR studies, the transcriptional activities of KiSS-1 in HF group animals were significantly higher than those from the control animals (p<0.001). Likewise, the mRNA levels of GnRH (p<0.05) were significantly elevated in HF group animals. The present study indicated that the feeding HF diet during the post-weaning period activates the upstream modulators of gonadotropin such as GnRH and KiSS-1 in hypothalamus, resulting early onset of puberty in immature female rats.

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The Change of ${\alpha}$-motor neuron excitability in Spastic Stroke Patients by Pre-tibia Muscle Isometric Contraction (전경골근 등척성 수축에 의한 경직성 뇌졸중 환자의 비복근 ${\alpha}$-운동 신경원 흥분 변화)

  • Kim, Jong-Soon;Lee, Hyun-Ok;Ahn, So-Youn
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.11 no.1
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    • pp.11-28
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    • 2005
  • Spasticity has been defined as "a motor disorder characterized by a velocity-dependent increased in tonic stretch reflexes with exaggerated tendon jerks, resulting from hyperexcitability of the stretch reflex, as one components of the upper motorneuron syndrome". Spasticity is one of the common symptoms of stroke patients and frequently interferes with the motor functions such as gait, posture and activities of daily living. Therefore, its management is becoming a major issue in physical therapy. The purpose of this study was to determined the effects of reciprocal inhibition by isometric contraction of pre-tibia muscle on spasticity in hemiplegic patients through Hoffmann reflex. The subjects were consisted 45 patients who had hemiplegia due to stroke. All subjects randomly assigned to 3 group: manual reciprocal inhibition program group(manual group), neuromuscular electrical stimulation group(NMES group) and control group. The manual group received voluntary isometric contraction of pre-tibia muscle. The NMES group received neuromuscular electrical stimulation on tibialis anterior. The control group was not received any therapeutic intervention. Before and after experiments, Hoffmann reflex, M-wave and Modified Ashworth scale was measure in all patients. The data of 30 patients who complete experimental course were statistically analysed. Modified Ashworth scale were significantly decreased after experiment in manual group(p<.01). The Hmax/Mmax ratios were significantly decreased after experiment in manual group(p<.o1). There were no statistical difference between pre-test and post-test with modified Ashworth scale in NMES group(p>.01). There were no statistical difference between pre-test and post-test with Hmax/Mmax ratios in NMES group(p>.01). There were no statistical difference between pre-test and post-test with modified Ashworth scale in control group(p>.01). There were no statistical difference between pre-test and post-test with Hmax/Mmax ratios in control group(p>.01). The present results revealed that reciprocal inhibition which produced by voluntary isometric contraction of pre-tibia muscle can be reduce spasticity of gastrocnemius. Therefore, reciprocal inhibition is useful to improve functional activities in hemiplegic patient. Further study should be done to analyse the effects of intervention duration of reciprocal inhibition, appropriate muscle contraction, optimal time to apply the reciprocal inhibition in more long period.

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Epigenomic Alteration in Replicative Senescent-mesenchymal Stem Cells (중간엽줄기세포의 노화에 따른 후생유전학적 변화)

  • Oh, Youn Seo;Cho, Goang-Won
    • Journal of Life Science
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    • v.25 no.6
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    • pp.724-731
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    • 2015
  • Mesenchymal stem cells (MSCs) are characterized by their multipotency capacity, which allows them to differentiate into diverse cell types (bone, cartilage, fat, tendon, and neuron-like cells) and secrete a variety of trophic factors (ANG, FGF-2, HGF, IGF-1, PIGF, SDF-1α, TGF-β, and VEGF). MSCs can be easily isolated from human bone-marrow, fat, and umbilical-cord tissues. These features indicate that MSCs might be of use in stem-cell therapy. However, MSCs undergo cellular senescence during long-term expansion, and this is accompanied by functional declines in stem-cell potency. In the human body, because of their senescence and declines in their microenvironmental niches stem cells fail to maintain tissue homeostasis, and as a result, senescent cells accumulate in tissues. This can lead to age-related diseases, including degenerative disorders and cancers. Recent studies suggest that the number of histone modifications to stem cells’ genomes and aberrant alterations to their DNA methylation increase as stem cells progress into senescence. These epigenetic alterations have been partly reversed with treatments in which DNA methyltransferase (DNMT) inhibitors or histone deacetylase (HDAC) inhibitors are introduced into replicative senescent-MSCs. This review focuses on epigenetic alteration in replicative senescent-MSCs and explains how epigenetic modifications are widely associated with stem-cell senescences such as differentiation, proliferation, migration, calcium signaling, and apoptosis.

A Study on Optimal Output Neuron Allocation of LVQ Neural Network using Variance Estimation (분산추정에 의한 LVQ 신경회로망의 최적 출력뉴런 분할에 관한 연구)

  • 정준원;조성원
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1996.10a
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    • pp.239-242
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    • 1996
  • 본 논문에서는 BP(Back Propagation)에 비해서 빠른 학습시간과 다른 경쟁학습 신경회로망 알고리즘에 비해서 비교적 우수한 성능으로 패턴인식 등에 많이 이용되고 있는 LVQ(Learning Vector Quantization) 알고리즘의 성능을 향상시키기 위한 방법을 논의하고자 한다. 일반적으로 LVQ는 음(negative)의 학습을 하기 때문에 초기 가중치가 제대로 설정되지 않으면 발산할 수 있다는 단점이 있으며, 경쟁학습 계열의 신경망이기 때문에 출력 층의 뉴런 수에 따라 성능에 큰 영향을 받는다고 알려져 있다.[1]. 지도학습 형태를 지닌 LVQ의 경우에 학습패턴이 n개의 클래스를 가지고, 각 클래스 별로 학습패턴의 수가 같은 경우에 일반적으로 전체 출력뉴런에 대해서 (출력뉴런수/n)개의 뉴런을 각 클래스의 목표(desired) 클러스터로 할당하여 학습을 수행하는데, 본 논문에서는 각 클래스에 동일한 수의 출력뉴런을 할당하지 않고, 학습데이터에서 각 클래스의 분산을 추정하여 각 클래스의 분산을 추정분산에 비례하게 목표 출력뉴런을 할당하고, 초기 가중치도 추정분산에 비례하게 각 클래스의 초기 임의 위치 입력백터를 사용하여 학습을 수행하는 방법을 제안한다. 본 논문에서 제안하는 방법은 분류하고자 하는 데이터에 대해서 필요한 최적의 출력뉴런 수를 찾는 것이 아니라 이미 결정되어 있는 출력뉴런 수에 대해서 각 클래스에 할당할 출력 뉴런 수를 데이터의 추정분산에 의해서 결정하는 것으로, 추정분산이 크면 상대적으로 많은 출력 뉴런을 할당하고 작으면 상대적으로 적은 출력뉴런을 할당하고 초기 가중치도 마찬가지 방법으로 결정하며, 이렇게 하면 정해진 출력뉴런 개수 안에서 각 클래스 별로 분류의 어려움에 따라서 출력뉴런을 할당하기 때문에 미학습 뉴런이 줄어들게 되어 성능의 향상을 기대할 수 있으며, 실험적으로 제안된 방법이 더 나은 성능을 보임을 확인했다.initially they expected a more practical program about planting than programs that teach community design. Many people are active in their own towns to create better environments and communities. The network system "Alpha Green-Net" is functional to support graduates of the course. In the future these educational programs for citizens will becomes very important. Other cities are starting to have their own progrms, but they are still very short term. "Alpha Green-Net" is in the process of growing. Many members are very keen to develop their own abilities. In the future these NPOs should become independent. To help these NPOs become independent and active the educational programs should consider and teach about how to do this more in the future.단하였는데 그 결과, 좌측 촉각엽에서 제4형의 신경연접이 퇴행성 변화를 나타내었다. 그러므로 촉각의 지각신경세포는 뇌의 같은 족 촉각엽에 뻗어와 제4형 신경연접을 형성한다고 결론되었다.$/ 값이 210 $\mu\textrm{g}$/$m\ell$로서 효과적인 저해 활성을 나타내었다 따라서, 본 연구에서 빈

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Impulse Trafficking in Neurons of the Mesencephalic Trigeminal Nucleus

  • Saito, Mitsuru;Kang, Young-Nam
    • International Journal of Oral Biology
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    • v.31 no.4
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    • pp.113-118
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    • 2006
  • In the primary sensory neuron of the mesencephalic trigeminal nucleus (MTN), the peripheral axon supplies a large number of annulospiral endings surrounding intrafusal fibers encapsulated in single muscle spindles while the central axon sends only a few number of synapses onto single ${\alpha}-motoneurons({\alpha}-MNs)$. Therefore, the ${\alpha}-{\gamma}$ linkage is thought to be very crucial in the jaw-closing movement. Spike activity in a ${\gamma}-motoneuron\;({\gamma}-MN)$ would induce a large number of impulses in single peripheral axons by activating many intrafusal fibers simultaneously, subsequently causing an activation of ${\alpha}-MNs$ in spite of the small number of synapses. Thus, the activity of ${\gamma}-MNs$ may be vital for modulation of jaw-closing movements. Independently of such a spindle activity modulated by ${\gamma}-MNs$, somatic depolarization in MTN neurons is known to trigger the oscillatory spike activity. Nevertheless, the trafficking of these spikes arising from the two distinct sources of MTN neurons is not well understood. In this short review, switching among multiple functional modes of MTN neurons is discussed. Subsequently, it will be discussed which mode can support the ${\alpha}-{\gamma}$ linkage. In our most recent study, simultaneous patch-clamp recordings from the soma and axon hillock revealed a spike-back-propagation from the spike-initiation site in the stem axon to the soma in response to a somatic current pulse. The persistent $Na^+$ current was found to be responsible for the spike-initiation in the stem axon, the activation threshold of which was lower than those of soma spikes. Somatic inputs or impulses arising from the sensory ending, whichever trigger spikes in the stem axon first, would be forwarded through the central axon to the target synapse. We also demonstrated that at hyperpolarized membrane potentials, 4-AP-sensitive $K^+$ current ($IK_{4-AP}$) exerts two opposing effects on spikes depending on their origins; the suppression of spike initiation by increasing the apparent electrotonic distance between the soma and the spike-initiation site, and the facilitation of axonal spike invasion at higher frequencies by decreasing the spike duration and the refractory period. Through this mechanism, the spindle activity caused by ${\gamma}-MNs$ would be safely forwarded to ${\alpha}-MNs$. Thus, soma spikes shaped differentially by this $IK_{4-AP}$ depending on their origins would reflect which one of the two inputs was forwarded to the target synapses.