热水器显示e6怎么修:研究者称自闭症患者的头脑发育慢于正常人

科学日报（2011年10月20日）——加利福尼亚大学的研究员或许已能够解释为什么患有自闭症的儿童的思维举止异于同龄人。首次，他们显示出患者大脑中一些区域的神经链接的发育速度远比正常儿童慢，这些区域影响着人的语言和社交能力。

Reporting in the current online edition of the journal Human Brain Mapping, senior author Jennifer G. Levitt, a professor of psychiatry at the Semel Institute for Neuroscience and Human Behavior at UCLA; first author Xua Hua, a UCLA postdoctoral researcher; and colleagues found aberrant growth rates in areas of the brain implicated in the social impairment, communication deficits and repetitive behaviors that characterize autism.

在加利福尼亚大学研究神经科学和人类行为的塞梅尔研究院，精神病学博士Jennifer G. Levitt 与博士后研究员Xua Hua 以及他们的同事发现在大脑某些区域不正常的发育速率导致了社交能力障碍，交流缺失和单调行为这些自闭症症状。他们分别作为首要者和第一作者把这一研结果发表在当前在线版本的《人类大脑图谱》杂志上。

Autism is thought to affect one in 110 children in the U.S., and many experts believe the numbers are growing. Despite its prevalence, little is known about the disorder, and no cure has been discovered.

在美国，每110个孩子里就有一个可能患有自闭症，许多专家也认为这个数字还在增长。尽管患者普遍，但人们对这种疾病所知甚少，而且还没研究出相应的治疗方案。

Normally, as children grow into teenagers, the brain undergoes major changes. This highly dynamic process depends on the creation of new connections, called white matter, and the elimination, or "pruning," of unused brain cells, called gray matter. As a result, our brains work out the ideal and most efficient ways to understand and respond to the world around us.

正常情况下，当儿童成长到青少年，大脑会发生显著的改变。这个高度动态的过程取决于新神经连接，即新“白质”的产生，同时丢弃不再使用的脑细胞也就是“灰质”的被消除或者“裁剪”。最终，我们的大脑演变出最理想和有效的方式去理解和反应周围的世界。

Although most children with autism are diagnosed before they are 3 years old, this new study suggests that delays in brain development continue into adolescence.

尽管大部分患有自闭症的儿童在三岁前就被检测出来，这项新研究表明这种大脑发育的滞后会延续到患者的青年时期。

"Because the brain of a child with autism develops more slowly during this critical period of life, these children may have an especially difficult time struggling to establish personal identity, develop social interactions and refine emotional skills," Hua said. "This new knowledge may help to explain some of the symptoms of autism and could improve future treatment options."

Hua 说，因为大部分患有自闭症的儿童的大脑在他们成长的重要阶段时发育得要缓慢一点，这些儿童，在建立自我认知，与社会互动和学习如何表达情感时，可能会经历一个艰难的时期。这个新发现可能有助于解释一些自闭症症状以及改善治将来的治疗方案。

The researchers used a type of brain-imaging scan called a T1-weighted MRI, which can map structural changes during brain development. To study how the brains of boys with autism changed over time, they scanned 13 boys diagnosed with autism and a control group of seven non-autistic boys on two separate occasions. The boys ranged in age from 6 to 14 at the time of the first scan; on average, they were scanned again approximately three years later.

研究员使用一种叫“T1-加权核磁共振器”的大脑镜像扫描仪，可以绘制出在大脑发育时的结构改变。为了研究患有自闭症的男孩的大脑是怎样随时间改变的，他们扫描了13个被诊断出患有自闭症的男孩，以及作为对照组的7个正常男孩，分开观察。这些男孩在第一次扫描时的年龄由6岁到14岁不等；他们在大约三年后会再被扫描一次。

By scanning the boys twice, the scientists were able to create a detailed picture of how the brain changes during this critical period of development.

通过对这些男孩的两次扫描，科学家可以细致地描绘出在这个重要的发育时期，大脑是如何变化的。

Besides seeing that the white-matter connections between those brain regions that are important for language and social skills were growing much slower in the boys with autism, they found a second anomaly: In two areas of the brain -- the putamen, which is involved in learning, and the anterior cingulate, which helps regulate both cognitive and emotional processing -- unused cells were not properly pruned away.

除了认识到患者大脑中影响语言和社交能力的区域之间的白质神经链接的发育速度远比正常儿童慢之外，他们还发现第二个异常之处: 与学习有关系的核壳，以及帮助控制认知和情感处理的前扣带。在大脑的这两部分里，一些没有再使用的细胞并没有被正确地裁剪掉。

"Together, this creates unusual brain circuits, with cells that are overly connected to their close neighbors and under-connected to important cells further away, making it difficult for the brain to process information in a normal way," Hua said.

Hua 说，这导致大脑的神经细胞连接出现异常，一些细胞过度的与临近的细胞相连而缺少与远处的重要细胞相连，使得大脑不能正常的处理信息。

"The brain regions where growth rates were found to be the most altered were associated with the problems autistic children most often struggle with -- social impairment, communication deficits and repetitive behavior," she added.

她还补充，大脑中被发现发育速率最异常的区域所控制的能力与患有自闭症的孩子经常遇到困难向关连 --- 社交障碍，交流缺失，单调行为。

Future studies using alternative neuroscience techniques should attempt to identify the source of this white-matter impairment, the researchers said.

研究员说更进一步的研究将使用另一种神经科学的技术来尝试找出导致这些白质异常的源头。

"This study provides a new understanding of how the brains of children with autism are growing and developing in a unique way," Levitt said. "Brain imaging could be used to determine if treatments are successful at addressing the biological difference. The delayed brain growth in autism may also suggest a different approach for educational intervention in adolescent and adult patients, since we now know their brains are wired differently to perceive information."

这一项研究对患有自闭症的孩子是以怎样一种独特的方式来成长的提供了一个新的见解，大脑镜像可以用来判断治疗是否有效，只要查看镜像体现的生理变化就行了。自闭症儿童大脑发展的延滞也会引入不同青少年教育方式以及家长的耐心，皆因我们已经知道他们的大脑以一种不同的方式来感知外界信息。

Other authors on the study included Paul M. Thompson, Alex D. Leow, Sarah K. Madsen, Rochelle Caplan, Jeffry R. Alger, Joseph O'Neill, Kishori Joshi, Susan L. Smalley and Arthur W. Toga, all of UCLA. Support was provided by the National Institutes of Health, the National Alliance for Autism Research, the National Institute of Mental Health and the National Institute of Neurological Disorders and Stroke.

参与这项研究的作者还包括 Paul M. Thompson, Alex D. Leow, Sarah K. Madsen, Rochelle Caplan, Jeffry R. Alger, Joseph O'Neill, Kishori Joshi, Susan L. Smalley 以及 Arthur W. Toga， 并得到国家卫生研究院，全国自闭症研究联盟，美国国家心理健康研究所和美国国家神经紊乱和中风研究所的支持

 (Credit: Carlos Mena, Courtesy of University of California - Los Angeles)

（Carlos Mena 撰写，加利福尼亚大学提供）