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2016～2019年度 科学研究費助成事業(基盤研究(A)(一般))研究成果報告書, publisher

2016～2019年度 科学研究費助成事業(挑戦的萌芽研究)研究成果報告書, publisher

2015年度～2017年度 科学研究費助成事業(基盤研究(C)（一般）)研究成果報告書, publisher

2013年度～2016年度 科学研究費助成事業(基盤研究(A))研究成果報告書, publisher

2013年度～2016年度 科学研究費助成事業(基盤研究(A))研究成果報告書, publisher

2014年度～2016年度 科学研究費助成事業(挑戦的萌芽研究)研究成果報告書, publisher

2011年度～2014年度 科学研究費補助金(基盤研究(C))研究成果報告書, publisher

2011年度～2014年度 科学研究費補助金(基盤研究(C))研究成果報告書, publisher

中枢神経系における最も主要な神経栄養因子である脳由来神経栄養因子(brain-derived neurotrophic factor ; BDNF)を,部位,細胞種,時期特異的に過剰発現させる目的でlox P-BDNFトランスジェニックマウスを作成した.BDNFが前脳特異的に生後より発現するように,αカルシウム/カルモデュリン依存性プロテインキナーゼIIプロモーター制御下でCre-recom-binaseを発現するマウスと交配したところ,大脳皮質などで強いBDNFの発現が観察された.ここで樹立したlox P-BDNFトランスジェニックマウスは神経細胞死やシナプス可塑性などを個体レベルで研究する優れたツールとなりうる.

フェンタニルの脳移行に及ぼすプロポフォールの影響について検討した.実験はラットを用い,フェンタニル単独またはプロポフォールと併用で単回静注した場合と,単独または併用で60分間持続静注した場合の血中濃度と脳内濃度を測定した.単回静注では,プロポフォール併用によってフェンタニルの血中濃度は変化しなかったが,脳内濃度は約2/3に低下した.脳血流量は単独と併用間に有意差はなかった.持続静注では,プロポフォールないし脂肪乳剤の併用で,血中濃度が単独投与の場合の約1.5倍に上昇したが,脳内濃度はプロポフォール併用で約1/2に低下した.脂肪乳剤のみの併用では,血中濃度は上昇したが脳内濃度は減少傾向を示す程度であった.以上より,プロポフォール併用でフェンタニルの脳移行が抑制され,脳血流量変化および脂肪乳剤の関与は否定的で,プロポフォール自体がBBBの能動輸送低下に関与していると考えられた.また,両剤の併用麻酔法では,血中と脳内濃度に乖離があり,投与量・投与速度には細心の注意が必要と思われた, 原著論文

The effect of hyperthermia on normal brain tissues and cerebrovascular permeability have recently been reported, but its critical temerature is not yet well determined. The present study was aimed at the effects by two different methods, whole body and RF interstitial heating. Whole body heatings of mongrel dogs were performed with extracorporeal systemic circulation method. The temperature of the brain was continously monitored. The permeability was assessed by injection of 10% fluorescein(FL.) and/or 2% Evans blue (EB) 30 min before sacrifice, followed fluorescence photograph or visual inspection of EB extravasation. Then, using paraffin embedded formalin fixed tissues, immunohistochemical demonstration of the animal's own serum albumin and fibrinogen using the ABC method was performed. No regions in the brain heated at 43℃ for 30 or 60 min showed FL. nor EB extravasation except blood-brain barrier lacking regions and a thermosensor penetrated Site. Immunohistochemical study also showed no abnormal extravasation of serum albumin nor fibrinogen. At the same heating conditions, no histological changes were seen. RF interstitial heatings of mongrel dogs were performed as follows. A RF antenna was inserted into the brain to a depth of 10 mm from the brain surface, and were also done 4 themosensors around the antenna. Monitoring a temperature at a reference point 5～7 mm distent from the antenna, the brain was heated at 42～45℃ for 60 min. The permeability was evaluated by tracer method using EB and immunohistochemistry as described in whole body heating. A 60 min heat treatment produced a round lesion that consisted of central coagulation necrosis surrounded by a well demarcated blue zone which was heated over 44℃. The blue zone dissappeared, and 24 hrs after the treatment, changed into a coagulative/liquefactive necrosis. The vascular pemeability and histological changes were also examined at various intervals from 1 to 30 days. On 7 and 9 days after treatment, faint E

Magnetic resonance imaging (MRI) has been comming to be one of the most important modalities in the diagnosis of the brain. MRI has many remarkable characteristics; (1) MRI does not utilize X-ray but magnetism for making images. Sequentially MRI does not contain deterious effect of X-ray. MRI provides us with new beneficial information which we are not able to take through X-ray CT. (2) Three parameters (i.e. T1 and T2 relaxation times and proton density) are available in MRI. (3) MRI shows high contrast resolution. (4) Scanning direction is freely selected. (5) Flow-imaging is also available. But MRI has also some controversial aspects. For example, it consume much time to make multi-directional and/or multisequential images. Many kinds of artifacts are seen in the images. These characteristics of MRI were evaluated in this paper.

Cholecystokinin (CCK), a brain gut peptide, which is assumed to be a neurotransmitter or a neuromodulater, may play an important role in mental and neurological function. The concentration of CCK in various regions of rat brains was determined by radioimmunoassay, and the receptor activity for ^3H-CCK in various areas of guinea pig brains was estimated. The effect of repeated administration of methamphetamine and haloperidol on the CCK concentration and CCK receptor were also studied. Administration of methamphetamine and haloperidol decreased CCK concentration in some areas of the brains, but the difference was not significant statistically. Administration of methamphetamine decreased CCK receptor binding (decreased receptor number) in the frontal cortex of guinea pig brains, which suggests that CCK is involved in some psychotic conditions caused by methamphetamine. Furthermore, using previously cloned CCK cDNA as a probe, the presence of the CCK gene in rat genomic DNA was demonstrated. Then, the CCK cDNA was applied to quantitate the CCKmRNA. Northern blot analysis showed that the size of CCKmRNA is about 850 nucleotides in length. Developmental changes and regional distribution of CCKmRNA in rat brain were also examined by dot blot hybridization. CCKmRNA was barely detectable in the fetal brain, but started to increase postnatally and attained a plateau level after 20-30 days. Further, the level of CCKmRNA was the highest in the frontal cortex and the lowest in the cerebellum, which correlated with the concentration of CCK.

We have applied the recombinant DNA technique to brain research. These studies contain 1) gene analysis of neurological diseases, 2) gene expression in the cells of the central nervous system, and 3) analysis of genes for proteins concerning the nerve function. In this report we describe an example of the third type from the above-mentioned studies. We carried out cDNA cloning for cholecystokinin (CCK), genomic DNA cloning and analysis of the structure of CCK genes. Further we show the developmental and regional changes of CCK mRNA using CCK cDNA as a probe.