Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, 60612, USA.
Brain Imaging Behav. 2011 Jun;5(2):126-36. doi: 10.1007/s11682-011-9117-4.
The present study examined the relationship between entorhinal cortex and hippocampal volume with fMRI activation during episodic memory function in elderly controls with no cognitive impairment and individuals with amnesic mild cognitive impairment (aMCI). Both groups displayed limited evidence for a relationship between hippocampal volume and fMRI activation. Smaller right entorhinal cortex volume was correlated with reduced activation in left and right medial frontal cortex (BA 8) during incidental encoding for both aMCI and elderly controls. However, during recognition, smaller left entorhinal cortex volume correlated with reduced activation in right BA 8 for the control group, but greater activation for the aMCI group. There was no significant relationship between entorhinal cortex volume and activation during intentional encoding in either group. The recognition-related dissociation in structure/function relationships in aMCI paralleled our behavioral findings, where individuals with aMCI displayed poorer performance relative to controls during recognition, but not encoding. Taken together, these results suggest that the relationship between entorhinal cortex volume and fMRI activation during episodic memory function is altered in individuals with aMCI.
本研究考察了在无认知障碍的老年对照组和遗忘型轻度认知障碍（aMCI）个体中，内侧前额叶皮层（BA8）左右脑区的 fMRI 激活与情景记忆功能的关系。两组均显示出海马体积与 fMRI 激活之间的关系有限。在情景记忆编码过程中，右内侧前额叶皮层（BA8）的 fMRI 激活与右内侧前额叶皮层（BA8）的体积呈负相关，而 aMCI 和老年对照组的右内侧前额叶皮层（BA8）的体积呈负相关。然而，在识别过程中，左内侧前额叶皮层（BA8）的体积与对照组的右侧 BA8 的激活减少有关，但 aMCI 组的激活增加。在两组中，均未发现内侧前额叶皮层体积与意向性编码期间的激活之间存在显著关系。aMCI 中结构/功能关系的识别相关差异与我们的行为发现相一致，即 aMCI 个体在识别过程中的表现相对于对照组较差，但在编码过程中则不然。综上所述，这些结果表明，在遗忘型轻度认知障碍个体中，内侧前额叶皮层体积与情景记忆功能的 fMRI 激活之间的关系发生了改变。
