BRAIN IN DIABETES: RESPONSE TO INCREASED METABOLIC DEMAND

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 海马体是一种位于颞叶深处的大脑结构，是学习和记忆的关键。研究人员和其他几个小组已经证明，在正常老年人中，MRI确定的海马体体积与最近的记忆表现直接相关。这项研究假设，外周葡萄糖代谢异常、核磁共振海马体体积减少和近期记忆表现之间存在特定的关联，与对照组相比，2型糖尿病患者的海马体和记忆力下降的程度将比糖尿病前期的人更大。此外，这些关系在解剖学和神经心理学上是特定的，在考虑到整体脑萎缩后将保持不变。它还假设大脑的灌流反应性将预测记忆能力和海马体体积。糖尿病患者对乙酰唑胺的脑血管反应迟钝，他们的记忆障碍和海马体体积减少最大。这些关系在解剖学和神经心理学上是特定的，在考虑到大脑萎缩后将保持不变。 本研究的目的如下：1)使用有效、可靠和标准化的方法，首次确定糖尿病近期记忆缺陷与海马体体积缩小之间是否存在特定的联系。研究人员将评估与匹配的正常对照组相比，患有2型糖尿病的个体以及现在被美国糖尿病协会(ADA)称为糖尿病前期的非糖尿病患者是否存在与MRI测量的海马体体积缩小具体相关的学习和记忆障碍。此外，研究人员将确定2型糖尿病患者是否比糖尿病前期患者在学习和记忆方面有更大的缺陷，以及海马体体积是否有更大的减少。2)为了确定与匹配的正常对照组相比，中年2型糖尿病患者是否对乙酰唑胺(Diamox)的脑血管扩张刺激表现出比糖尿病前期患者更低的血管舒缩反应性。研究人员还将评估这种血管运动反应性降低是否与记忆障碍和海马体体积减少有特殊关系。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The hippocampus, a brain structure located deep in the temporal lobe, is key for learning and memory. The investigators and several other groups have shown that among normal elderly the MRI-determined volume of the hippocampus is directly related to recent memory performance. The study hypothesizes that there is a specific association between abnormalities in peripheral glucose metabolism and reductions in MRI-derived hippocampal volumes and recent memory performance and that, relative to controls, individuals with type-2 diabetes will have greater hippocampal and memory reductions than those with pre-diabetes. In addition, these relationships will be anatomically and neuropsychologically specific and will remain after accounting for overall brain atrophy. It also postulates that cerebral perfusion reactivity will predict memory performance and hippocampal volumes. Diabetics, who have been shown to have a blunted cerebral vascular response to acetazolamide, will have the largest memory impairments and hippocampal volume reductions. These relationships will be anatomically and neuropsychologically specific and will remain after accounting for brain atrophy. The objectives of the study are as follows: 1) To ascertain for the first time whether there are specific associations between recent memory deficits in diabetes and volume reductions of the hippocampus using validated, reliable, and standardized methods. The investigators will assess whether relative to matched normal controls, individuals with type-2 diabetes as well as non diabetic subjects with insulin resistance syndrome, who are now referred to by the American Diabetes Association (ADA) as having pre-diabetes, have learning and memory impairments that are specifically associated with hippocampal volume reductions measured with MRI. In addition, the investigators will ascertain whether individuals with type-2 diabetes have greater deficits in learning and memory, as well as larger reductions in hippocampal volumes, than prediabetic individuals. 2) To ascertain whether relative to matched normal controls, mid-life individuals with type-2 diabetes show less vasomotor reactivity in response to the cerebral vasodilating stimulus of acetazolamide (Diamox) than those with pre-diabetes. The investigators will also assess whether this diminished vasomotor reactivity is specifically related to memory impairments and hippocampal volume reductions.