迄今最完整人脑基因图谱出炉

2011/04/15 22:59:14

至少82%的人类基因都会在大脑中表达

据美国麻省理工学院出版的《技术评论》杂志4月13日报道，艾伦脑科学研究所的科学家绘制出了两个迄今最完整的人脑基因图谱，为神经科学研究提供了重要的数据支撑。科学家表示，最新“出炉”的人脑基因图谱提供的数据将被广泛用于与帕金森症、精神分裂症、多发性硬化症甚至肥胖等与神经障碍和认知功能有关的疾病的研究，以及探究健康的大脑如何工作。

科学家将相关数据编制成一个名为“艾伦人脑图谱”的数据库，该图谱除了显著标识出人类基因图谱中的每个基因在大脑的何处表达之外，还涵盖了大脑核磁共振成像（MRI）和磁共振弥散张量成像（DTI）提供的数据，供公众自由免费访问。这些数据显示，人脑之间的相似度高达94%，至少82%的人类基因都会在大脑中表达。

2002年，微软公司的共同创始人之一保罗·艾伦出资一亿美元成立了脑科学研究所，并着手进行大脑基因谱图的绘制工作。2006年，该研究所公布了实验鼠的大脑基因图谱，为开启人类大脑之谜迈出了重要一步。

艾伦脑科学研究所的首席执行官艾伦·琼斯表示：“这是迄今为止科学家绘制出的最全面最精确的人脑基因图谱，让我们能更深层地洞悉人体最复杂、最重要的器官；理解基因在大脑中如何运作；帮助科学家和医学工作人员更好地理解各种精神疾病和大脑疾病，并研发出新的药物和治疗方法。”

与高性能、多功能的全球定位系统（GPS）一样，艾伦人脑图谱确定了人脑中的1000个解剖点，指明了每个点上特定的基因表达和基本的生物化学特性。科学家能借用艾伦人脑图谱探测人脑，厘清人脑遭受的疾病和损伤（包括生理损伤和精神健康疾病）对大脑特定区域的影响。科学家有望借此准确定位出某种特定的药物应作用于大脑的哪个区域并最终更好地控制很多疗法的治疗结果。

A Detailed Gene Map of the Human Brain

The Allen Institute for Brain Science has released the most comprehensive catalogue yet of the brain’s biochemistry, providing an important new resource for neuroscientists.

By Emily Singer

A tale of two brains. On the left, a 3D viewer shows two brains; the stripes on outer surface represent expression of a gene in different areas of the cortex, while the dots (most of which are hidden under the surface in this view), reflect expression of the gene in deeper areas of the brain. Users can a dive deeper into the massive amount of quantitative and other data, as shown on the right.

Scientists have mapped the biochemistry and anatomy of two human brains in comprehensive detail, compiling the data into a publicly accessible database called the Allen Human Brain Atlas. In addition to maps highlighting where in the brain each gene in the genome is expressed, the atlas includes brain imaging data derived from magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI).

According to a release from the institute, the data “reveal a striking 94 percent similarity between human brains”. In addition, “data analysis from the two human brains indicate that at least 82 percent of all human genes are expressed in the brain, highlighting its tremendous complexity while also providing an essential genetic blueprint to understand brain functionality better and propel research in neurologic disease and other brain disorders.”

Pinky and the brain. A researcher examines a cross-section of the human brain stained to determine the quality and integrity of the specimen.

The human map follows release of a mouse version that the institute released in 2006. The human data will likely be used in studies examining a broad range of neurological disorders and cognitive functions, such as Parkinson’s disease, schizophrenia, multiple sclerosis and even obesity. According to the institute, about 4,000 unique visitors are accessing the new Atlas each month.

A happy brain. The dots on this brain image indicate where the antidepressant Prozac acts on the internal structures of the brain. Researchers can drill down deeper for each dot and retrieve a detailed picture of the biochemistry at that location (analogous to a detailed view of everything in a particular neighborhood in a GPS).

“Until now, a definitive map of the human brain, at this level of detail, simply hasn’t existed,” said Allan Jones, Ph.D., Chief Executive Officer of the Allen Institute for Brain Science. “The Allen Human Brain Atlas provides never-before-seen views into our most complex and most important organ. Understanding how our genes are used in our brains will help scientists and the medical community better understand and discover new treatments for the full spectrum of brain diseases and disorders, from mental illness and drug addiction, to Alzheimer’s and Parkinson’s diseases, multiple sclerosis, autism and more.”

Similar to a high-powered, multi-functional GPS navigation system, the Allen Human Brain Atlas identifies 1,000 anatomical sites in the human brain, backed by more than 100 million data points that indicate the particular gene expression and underlying biochemistry of each site. Scientists can use the Allen Human Brain Atlas to explore the human brain and identify how disease and trauma, including physical brain injuries and mental health disorders, affect specific areas of the brain. This powerful resource makes it possible to pinpoint where a particular drug acts anatomically in the brain, to ultimately better control the successful outcome of numerous therapies.

It is anticipated that the Allen Human Brain Atlas will be used in small and large-scale applications to examine diseases and disorders, such as obesity, Parkinson’s disease, autism, schizophrenia, Alzheimer’s disease and multiple sclerosis — as well as those exploring how the healthy brain works.