title: Altered brain activation patterns under different working memory loads in patients with type 2 diabetes.
abstract: OBJECTIVE
  Type 2 diabetes mellitus (T2DM) has important effects on cognition and the risk for Alzheimer disease (AD). Working memory (WM) is a susceptible cognitive domain of mild cognitive impairment and AD. Thus, the identification of brain activation patterns under different WM loads can potentially enhance our understanding of the mechanisms underlying cognitive dysfunction in T2DM.
  
  
  METHODS
  The current study assessed the effects of T2DM on cognitive performance and explored the related neuronal damage through a visual n-back task and functional magnetic resonance imaging.
  
  
  RESULTS
  We found that patients with T2DM exhibited worse executive and memory abilities than control subjects. Furthermore, the patterns of brain activation changed under different WM loads in the T2DM patients, who exhibited reduced activation in the left inferior frontal gyrus under low loads and reduced activation in the left middle frontal gyrus and superior frontal gyrus (SFG) under high loads. Thus, more regions of diminished activation were seen in the frontal cortex with increasing task difficulty. Furthermore, we found that lower SFG activation was associated with worse cognitive function.
  
  
  CONCLUSIONS
  The findings demonstrate deficient WM in patients with T2DM and the relation between cognitive function and degree of neuronal activity and their relevance to AD risk. Further longitudinal studies are needed to replicate these results and to evaluate the clinical value of brain imaging methods in the prediction of disease progress in these patients.
authors.affiliation: State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China BABRI Centre, Beijing Normal University, Beijing, China Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China.
authors.forename: Yaojing
authors.initials: Y
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China BABRI Centre, Beijing Normal University, Beijing, China Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China BABRI Centre, Beijing Normal University, Beijing, China Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China.
authors.forename: Junying
authors.initials: J
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China BABRI Centre, Beijing Normal University, Beijing, China Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China BABRI Centre, Beijing Normal University, Beijing, China Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China.
authors.forename: Sisi
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China.
authors.forename: Dongfeng
authors.initials: D
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China BABRI Centre, Beijing Normal University, Beijing, China Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China Institute of Basic Research in Clinical Medicine, China Academy of Traditional Chinese Medicine, Beijing, China zhang_rzs@bnu.edu.cn.
authors.forename: Zhanjun
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000368:Aged; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping / Q000379:methods; D003071:Cognition / Q000502:physiology; D060825:Cognitive Dysfunction / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000503:physiopathology / Q000523:psychology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D008875:Middle Aged; D009483:Neuropsychological Tests