ＤＮＡの模型（参考）

１２月の自閉症関連の記事から
１つ目の記事＝自閉症の初めての遺伝子の動物モデル
２つ目の記事＝ＭＩＴは共同研究で発表をしたようです。タンパク質の活動のキーである酵素を発見。
無くなったタンパク質は　自閉症へのキーかもしれません・・・

本当にこんな事がおこったら良いのに・・・祈るような思いで、いつも私は　切ないくらいの希望を　キャンドルの炎のようにゆらしながら・・くらしています。
いつかそこに　普通に発達して　普通に話ができる　まこちゃんが立っていたら・・と。
『何かの発見で、この魔法の薬を飲んだら、自閉症なんて、ほら、瞬時に消えて無くなる〜〜〜☆」なんて　シンデレラのような魔法使いが現れることを　心待ちにしています。
でも・・・安心してください・・・怪しい薬や、怪しい呪術には　手を出していませんから・・（笑）

１．『自閉症の初めての遺伝子の動物モデル』＝自動翻訳なので、内容はかなり怪しいかも・・・

マウスで遺伝子突然変異を持ち出すことによって、アメリカのNeuropsychopharmacology年次総会大学で提示される研究によると、調査者は彼らがより幅広い神経精神病学的症候群を伴わない自閉症の最初の精密なモデルであると思っているものをつくりました。
この動物モデルはよりよく研究者が自閉的な人間で異常な脳機能を理解するのを援助することができました。そして、それは彼らが処置戦略を確認して、利用するのを援助することができました。より幅広い神経精神病学的状況は壊れやすいX、継承した精神的欠陥で最も一般的な原因とRett Syndromeを含みます。そして、小児期neurodevelopmentalな障害が遅くなる脳と頭部発育、発作と精神遅滞が続く通常の初期の成長によって特徴づけられます。
自閉症は、反復的な性質によって、そして、社会的インタラクションとコミュニケーション技術の障害によって特徴づけられる神経精神病学的障害です。これらの徴候は、強化されたか減少した認識能力と技術と共存することができます。
「この研究の前に、我々は脳で自閉症のメカニズムについて、ほとんど何も知りませんでした」と、勉強研究者クレイグM.パウエル博士（博士、神経学の助教授とダラスのテキサス大学Southwestern Medicalセンターの精神医学）が言います。「この研究で、我々は自閉的な性質と徴候に至る脳の変化を調査することができます。そして、それは我々がより障害の進行と治療についてよく知っているのを援助するかもしれません。」、研究チーム（UT Southwesternで神経科学のトーマス、M.D.、教授と議長によって導かれる）は、人間で通常のマウスneurologin-3遺伝子を自閉症と関連した変異するneuroligin-3遺伝子と入れ替えました。そうすることによって、チームはヒト自閉症病遺伝子と類似しているマウスで遺伝子をつくることができました。結果が彼らの遺伝子の化粧の非常に小さな変化に達する間、それは完全に、一部の人間の自閉症患者に起こっている同じ小銭に擬態しました。
パウエル博士は遺伝子組み換えマウスを研究して、自閉症の鍵となる徴候を反映するかもしれない行動のテストで調べられるとき、彼らが他のマウスで減少した社会的インタラクションを示したとわかりました;他の特徴（例えば不安、調整と痛み感度）は、影響を受けなかったです。これらの社会的インタラクション赤字は、人間の自閉症の特質特徴であると、パウエル博士が言います。そのうえ、マウスは強化された空間学習能力を示しました。そして、それは自閉的な学者（並外れた精神的な能力と同様にひどい発達上であるか精神的な障害がある人々）の点で強化された認識能力に似ているかもしれません。
「これらの調査結果は、特に新しい処置アプローチを確認するのに有効でありえました。我々は、1つのニューロンから次への抑制化学シナプス伝達がこのマウスモデルで増やされるということをすでに知っています。現在、我々はマウスで直接この影響を減少させる薬をテストすることができて、これが彼らの社会的インタラクション赤字を逆にするかどうか尋ねることができます」と、パウエル博士が言います。「今のところ、自閉症治療のメーンステーは、まだ行動療法です。我々がより早く患者を行動の干渉で関係してもらうことができるほど、自閉症の人々は、より裕福です。」、パウエル博士はモデルが研究者に重要な平行を人間を送る頭と共有するマウス頭に対する洞察をすると付け加えます。そして、それは新しい脳イメージングツールを使って限られた方向で勉強されることができるだけです。

First-Ever Genetic Animal Model Of Autism

By introducing a gene mutation in mice, investigators have created what they believe to be the first accurate model of autism not associated with a broader neuropsychiatric syndrome, according to research presented at the American College of Neuropsychopharmacology annual meeting. This animal model could help researchers better understand abnormal brain function in autistic humans, which could help them identify and improve treatment strategies. Broader neuropsychiatric conditions include Fragile X, the most common cause of inherited mental impairment, and Rett Syndrome, a childhood neurodevelopmental disorder characterized by normal early development followed by slowed brain and head growth, seizures, and mental retardation.
Autism is a neuropsychiatric disorder characterized by repetitive behaviors and by impairment in social interactions and communication skills. These symptoms can coexist with either enhanced or decreased cognitive abilities and skills.
"Prior to this study we knew next to nothing about the mechanisms of autism in the brain," says study researcher Craig M. Powell, M.D., Ph.D., assistant professor of neurology and psychiatry at the University of Texas Southwestern Medical Center at Dallas. "With this research, we can study changes in the brain that lead to autistic behaviors and symptoms, which may help us understand more about progression and treatment of the disorder."
The research team, led by Thomas S歸hof, M.D., professor and chairman of neuroscience at UT Southwestern, replaced the normal mouse neurologin-3 gene with a mutated neuroligin-3 gene associated with autism in humans. By doing so, the team was able to create a gene in the mice that is similar to the human autism disease gene. While the result amounted to a very small change in their genetic makeup, it perfectly mimicked the same small change occurring in some patients with human autism.
Dr. Powell studied the genetically altered mice and found that, when examined in behavioral tests that may reflect key signs of autism, they showed decreased social interaction with other mice; other traits, such as anxiety, coordination and pain sensitivity, were unaffected. These social interaction deficits, Dr. Powell says, are hallmark features of human autism. In addition, the mice showed enhanced spatial learning abilities, which may resemble the enhanced cognitive abilities in autistic savants (people who have a severe developmental or mental handicap as well as extraordinary mental abilities).
"These findings could be especially helpful in identifying novel treatment approaches. We already know that inhibitory chemical synaptic transmission from one neuron to the next is increased in this mouse model. Now we can test drugs that decrease this effect directly in the mice and ask whether this reverses their social interaction deficits," Dr. Powell says. "For now, the mainstay of autism treatment is still behavioral therapy. The earlier we can get patients involved with behavioral interventions, the better off people with autism will be." Dr. Powell adds that the model gives researchers insight into mouse brains which share important parallels with brains of living humans, which can only be studied in limited ways with the use of new brain imaging tools.
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Article adapted by Medical News Today from original press release.
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ACNP, founded in 1961, is a professional organization of more than 700 leading scientists, including four Nobel Laureates. The mission of ACNP is to further research and education in neuropsychopharmacology and related fields in the following ways: promoting the interaction of a broad range of scientific disciplines of brain and behavior in order to advance the understanding of prevention and treatment of disease of the nervous system including psychiatric, neurological, behavioral and addictive disorders; encouraging scientists to enter research careers in fields related to these disorders and their treatment; and ensuring the dissemination of relevant scientific advances.
Source Sharon Reis
American College of Neuropsychopharmacology

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MIT: Missing Protein May Be Key To Autism

A missing brain protein may be one of the culprits behind autism and other brain disorders, researchers at MIT's Picower Institute for Learning and Memory report in the Dec. 6 issue of Neuron.
The protein helps synapses develop. Synapses--through which neurons communicate with one other-underlie our ability to learn and remember. Now Li-Huei Tsai, Picower Professor of Neuroscience at MIT, has uncovered an enzyme that is key to that protein's activity.
Synapses are complex structures consisting of ion channels, receptors and intricate protein complexes that all work together to send and receive signals. Improperly formed synapses could lead to mental retardation, and mutations in genes encoding certain synaptic proteins are associated with autism.
Tsai studies a kinase (kinases are enzymes that change proteins) called Cdk5. While Cdk5's best-known role is to help new neurons form and migrate to their correct positions during brain development, "emerging evidence supports an important role for Cdk5 at the synapse," she said.
To gain a better understanding of how Cdk5 promotes synapse formation, Tsai's lab looked into how Cdk5 interacts with synapse-inducing proteins-in particular, a protein called CASK. CASK--a key scaffolding protein-is one of the first proteins on the scene of a developing synapse.
Scaffolding proteins such as CASK are like site managers, supporting protein-to-protein interactions to ensure that the resulting architecture is sound. Mutations in the genes responsible for Cdk5 and CASK have been found in mental retardation patients.
"We found that Cdk5 is critical for recruiting CASK to do its job for developing synapses," Tsai said. "Without Cdk5, CASK was not in the right place at the right time, and failed to interact with essential presynaptic components. This, in turn, led to problems with calcium influx." The flow of calcium in and out of neurons affects processes central to nervous system development and plasticity--its ability to change in response to experience.
Gene mutations and/or deletions in synaptic cell surface proteins and molecules called neurexins and neuroligins have been associated with autism. The problem with CASK recruitment investigated by the Tsai laboratory creates the same result as these genetic changes.
The Picower study also provides the first molecular explanation of how Cdk5, which also may go awry in neurodegenerative diseases such as Alzheimer's, promotes synapse development.
"There are still a lot of unknowns," said Tsai, who is also a Howard Hughes Medical Institute investigator. "Causes for psychiatric disorders are still very unclear, but accumulating evidence strongly suggests that alterations in the synaptogenesis program can lead to these serious diseases."
In addition to Tsai and Picower researcher Benjamin A. Samuels, co-authors are associated with Harvard Medical School; Johns Hopkins University School of Medicine; McLean Hospital in Belmont, Mass.; and Academia Sinica in Taiwan.
This work is supported by the National Institute of Neurological Disorders and Stroke (NINDS).
Massachusetts Institute of Technology