Crosstalk Between Brain-Derived Neurotrophic Factor And N-Methyl-D-Aspartate Receptor Signaling In Neurons

Glutamate is the major excitatory neurotransmitter in brain exerting prosurvival effect on neurons via N-methyl-D-aspartate receptor (NMDAR) signaling under physiological conditions. However in pathological circumstances such as ischemia, NMDARs might have proapoptotic excitotoxic activity. In contrast brain-derived neurotrophic factor (BDNF) signaling via TrkB receptors has been largely considered to promote neuronal differentiation, plasticity and survival during normal development, and protect neurons in pathophysiological conditions antagonizing the NMDAR-mediated excitotoxic cell death. In this review we summarize recent evidence for the existent crosstalk and positive feedback loops between the BDNF and NMDAR signaling and point out some of the important specific features of each signaling pathway

Crosstalk between brain-derived neurotrophic factor and N-methyl-D-aspartate receptor signaling in neurons

Glutamate is the major excitatory neurotransmitter in brain exerting prosurvival effect on neurons via N-methyl-D-aspartate receptor (NMDAR) signaling under physiological conditions. However in pathological circumstances such as ischemia, NMDARs might have proapoptotic excitotoxic activity. In contrast brain-derived neurotrophic factor (BDNF) signaling via tropomyosinrelated receptor kinase B (TrkB) has been largely considered to promote neuronal differentiation, plasticity and survival during normal development, and protect neurons in pathophysiological conditions antagonizing the NMDAR-mediated excitotoxic cell death. In this review we summarize recent evidence for the existent crosstalk and positive feedback loops between the BDNF and NMDAR signaling and point out some of the important specific features of each signaling pathway.Biomedical Reviews 2008; 19: 17-27

Modulation by static magnetism of neuronal activity

In neurons, the signal propagation involves both the conduction mediated by local electric currents through voltage-sensitive cation channels in axons and the transmission mediated by the exocytotic release of neurotransmitters from nerve endings into synaptic clefts. A great number of desperate efforts have been dedicated to biochemical, pharmacological and molecular biological studies on the elucidation of mechanisms underlying the neurotransmission at synapses, while relatively little attention has been paid to the comprehensive evaluation of the conduction except for local anesthetics. According to a physical theorem, exposure to magnetism should lead to the generation of a certain mechanical force in neurons with concomitant electric currents in a particular situation. In particular, repetitive transcranial magnetic stimulation is beneficial for the treatment of selected patients suffering from depression, bipolar affective disorder and schizophrenia as a possible alternative to the electroconvulsive therapy for refractory depression. In this review, therefore, we will summarize our recent advances made on the neurochemical and molecular biological elucidation in cultured rat hippocampal neurons toward better understanding by the readers of different disciplines of mechanisms associated with the modulation by magnetism of the neuronal activity in the brain.Biomedical Reviews 2004; 15: 21-35

チュウゴク ノ ヘンキョウ カイホウ セイサク

中国は、長い国境線をもち、隣接する国も多い。1992年以来、中国が推進している辺境開放政策は、伝統的な国境貿易の活性化、円滑化を図ることを通じて、内陸省、自治区の経済発展を促進しようということだけでなく、隣接国家との全般的な経済交流を展開しようということ、そして中国の長期的な資源戦略と拡大アジアとの経済統合への基礎を築こうとするものと思われる。交流相手として選択の余地がない隣接国家との経済緊密化を優先する中国は、海を挟む非隣接国家である日本や韓国を包含する東アジア共同体の実現には、当面慎重な姿勢を続けるであろう。China has a very long borderline and many neighboring countries. The open-borderline policy which China is pursuing since 1992, seems to target not only the economic development of inland states and self-governing districts through empowerment of traditional border trade, but also the overall economic exchanges with neighboring countries. Additionally, it aims to build the base for China\u27s long-term resource strategy and economic integration with enlarged Asia. China, which prefers to have the better economic relationship with neighboring countries as unavoidable partners, hesitates for the time being to progress toward the East Asian Community that includes beyond-the-sea nations such as Korea and Japan

カイハツ ドクサイ ノ サイケントウ

開発独裁は日本独自の用語法で、一般には権威主義的開発国家と呼ばれるが、東アジアの工業化過程で一時的に出現した国家形態として再定義されるべきだと思われる。開発独裁の経済的役割を明らかにするためには、収奪国家と開発国家、開発主義国家と開発国家という2段階の概念上の区別が必要である。既存研究の多くは開発国家と開発主義を同一とし、市場経済を原則とする点で社会主義と区別されるキャッチアップ型工業化をめざす権力型政権ととらえており、これでは東アジアの特質を理解できない。多くの途上国は、官僚専制と経済計画の導入を通じて収奪国家を克服しようとする開発主義(国家)の段階にとどまっているが、東アジア諸国は対外志向戦略を採用することによって開発国家へまで進むことができたのである。The term, developmental dictatorship, which is used especially in Japan, but generally called as an authoritarian developmental state, should be redefined as a type of state that appeared at one time in East Asia when it was industrialized. In order to know the economic role of developmental dictatorship, it is necessary to discriminate an exploitative state from a developmental state, and also a development-oriented state from a developmental state. The most of precedent studies that identify a development-oriented state as a developmental state, see them to be an authoritarian state pursuing the catch-up type industrialization on the principally market economy in which point differed from the socialist economy and thus failed to understand the characteristics of East Asia.Many developing countries stay as a development-oriented state making effort to conquer an exploitative state by introducing bureaucratic autocracy and economic planning. However, East Asia progressed to a developmental state by adopting the outward looking strategy

カンコク ノ セイネン シツギョウ モンダイ

21世紀に入って、韓国では30歳未満の青年層の失業問題が「青年失業」という名の下に注目されている。1997年の経済危機で大量失業事態を引き起こしたが、2001年以降30歳以上層では失業率は3%内外に低下する一方で、青年層は7%台に止まったままなのである。その要因として、労働市場の変化、企業の経歴者・非正規職選好が高学歴化・経験不足の青年層の希望とミスマッチしていることがあげられている。本論では、韓国の変化している労働市場の実態、高学歴化と学卒者の就職難の状況を検討し、高学歴化のなかで大学教育がむしろ青年たちの社会適応とくに職業適応能力の向上を阻害しているという仮説を導き出している。The total unemployment ratio in South Korea has decreased much since the beginning of 21 century, but that of youth is still staying at high level. The cause of high unemployment ratio of youth is considered as resulting from the change of labor market and thus the policy makers are trying to improve the conditions of the market. The author pays more attention on the supply side of the labor market especially the youth with higher school career. The Korean higher educational system, namely university level is seemed failing to give students the power necessary for adapting them to real society

Repeated Hepatic Dearterialization for Unresectable Liver Metastases From Gastric Cancer: Review of Five Cases

A novel method of repeated hepatic dearterialization was evaluated in five patients with multiple metastases from gastric cancer in both hepatic lobes. After gastrectomy with extensive lymph node dissection (R2/3), all patients underwent implantation of a vascular occluder around the hepatic artery. Cannulation of the hepatic artery was added for later chemotherapy. The hepatic artery was occluded repeatedly for 1 hour twice daily in combination with intrahepatic infusion of anticancer drugs for as long as possible. Three of five patients demonstrated marked tumour regression with unexpectedly long survival (16 months in two patients and one still alive at 15 months). Carcinoembryonic antigen (CEA) levels decreased to almost normal in four patients who had initially high levels. The present experiences seems to indicate that long survival can be hoped for in patients with advanced gastric cancer with unresectable liver metastases

Possible expression of functional glutamate transporters in the rat testis

Neither expression nor functionality is clear in peripheral tissues with the molecular machineries required for excitatory neurotransmitter signaling by L-glutamate (Glu) in the central nervous system, while a recent study has shown that several Glu receptors are functionally expressed in the rat testis. This fact prompted us to explore the possible functional expression in the rat testis of the Glu transporters usually responsible for the regulation of extracellular Glu concentrations in the brain. RT-PCR revealed the expression, in the rat testis, of mRNA for five different subtypes of Glu transporters, in addition to that for particular subtypes of ionotropic and metabotropic Glu receptors. Glutamate transporter-1 (GLT-1) was different in the brain from that in the testis in terms of molecular sizes on Northern and Western blot analyses. In situ hybridization as well as immunohistochemical analysis showed localized expression of glutamate aspartate transporter at interstitial spaces and GLT-1 at elongated spermatids in the rat testis respectively. The expression of mRNA was localized for excitatory amino acid transporter-5 at the basal compartment of the seminiferous tubule in the rat testis. [3H]Glu was accumulated in testicular crude mitochondrial fractions in a temperature-and sodium-dependent saturable manner with pharmacological profiles similar to those shown in brain crude mitochondrial fractions. These results suggested that particular subtypes of central Glu transporters for the regulation of extracellular Glu concentrations in the rat testis could be constitutively and functionally expressed. © 2004 Society for Endocrinology